Sharpening bars for knives. Sharpening knives: how to do it right? Natural Knife Sharpening Bars

For those who are not in the subject, so that there are no misunderstandings, I will explain the terms used:

Blade- The part of the knife that is not a handle. Usually made from steel or ceramic.

Butt- the back of the blade opposite to the cutting side.

The descent- the constriction going from the butt to the cutting part. For knives with a wedge-shaped section, the entire blade is made in the form of a descent. But with many knives, such as the finca, the escapement takes up only a third of the width of the blade, while the rest remains a flat plate.

Cutting edge(edge, RK) - the edge of the knife used for cutting.

Approach (chamfer)- a sharpening going from the slope to the cutting edge. Usually, the approach ends the descents, making the knife finally sharp (theoretically, knives where the descents end with a cutting edge without the approach are possible). Almost always, the approach has a certain angle to the descent. If the knife is not altered, but simply sharpened, then it is the supply that is processed.

Micro lead (micro bevel)- the part of the approach is closer to the cutting edge, sharpened, in relation to the rest of the approach, at a more obtuse angle. Micro-leads are sometimes made deliberately, usually with a thinner abrasive, to increase the edge resistance (the so-called step). But sometimes they are the inevitable result of hand sharpening on a bar without rigid fixation, as a result of which the lead is slightly rounded. Since, when finishing sharpening on thin bars, they try to hold the corner more carefully, at the end of sharpening, the supply turns out to be a shaped coarse bar, gradually changing the angle and passing into a finer sharpening.

Micro-feed is not a prerequisite for good sharpness. Moreover, if done incorrectly (usually due to the difficulty of controlling the angle), the knife becomes duller than it was before the formation of the micro-feed. At the same time, the knife can cut well and for a long time. So, usually, even an unsuccessful micro lead does not spoil the sharpening. However, shaving starts to get worse, or stops shaving altogether.

Machine- usually an electric sharpening machine with a circle or tape. Used in industry to quickly form slopes (if they are not forged) and cutting edges. In everyday life, it can be used to quickly resharpen a knife at a new angle and create new carts. Some non-craftsmen try to use the machine for other purposes and, instead of altering or making a knife, try to sharpen it. This leads to unnecessary removal of metal, as a result of which, after several such sharpenings, the knife is disfigured. At the same time, it is not possible to achieve good sharpness on the machine (unless, of course, you have a set of disks of the required grain size, which in reality you never have). And, in fact, by sharpening a knife on a machine, people simply render the knife unusable.

In addition, sharpening on the machine often leads to overheating of the metal, as a result of which the knife is quenched, becomes soft and quickly dulls, requiring frequent sharpening.

Plate Broaching Sharpener- plates of hard steel or ceramics directed towards each other, between which it is proposed to drive a knife, peeling against the plates. As a result of peeling, the edge of the knife is thinned, increasing the sharpness. However, this peeling destroys the metal structure on the knife, leaving deep grooves (when viewed under a microscope) and stretching the metal. As a result, the edge is very unstable, it quickly becomes blunt, wrinkled, crumbled. It is necessary to sharpen often, spending extra time on it and killing the knife.

The longitudinal grooves left by the sharpener prepare the metal for quick fracture.
As a result, the knife quickly dulls and requires a new sharpening, and this increases wear and tear.

Musat- similar to a round file. Metal scraps are designed to unfold the crumpled edge on soft knives. It is impossible to sharpen a knife well on metal rubbish. For knives made of solid steel, metal scum is generally useless. Ceramic musats are usually a round sharpening stone and allow you to both unfold the edge and sharpen the knife. However, good sharpening of a knife on them is an almost impossible task. Sharpening bars of a square cross section, with a thickness of the order of a centimeter, can be attributed to musats. Sharpening on this hybrid is inconvenient, however, like on ceramic waste, you can both unfold the edge and sharpen the knife.

Since it is possible to unfold the edge not only with metal scraps, but also with the butt of another knife, and for hard steels, scraps are useless, the practical value of scraps tends to zero. Whether to use musat or not is a matter of taste. But the musat is convenient when there is no desire to wash the knife. You cannot use a dirty knife on a sharpening stone - the stone will then have to be cleaned for a long time. And the musat can be easily washed off. So, the presence of musat on hand will be convenient for butchers when cutting carcasses.

There is a widespread misconception that the grind treats the knife more carefully than a whetstone, since it does not remove a lot of metal. But, firstly, there is no need to edit the knives with shaving stones, and secondly, loosening the edge in different directions, musat does not make it stronger. So, with the ability to use stones, the choice and the ability to wash the knife, musat becomes superfluous.

Sharpening system- a system for manual sharpening of a knife, which allows you to do this with a constant preservation of the sharpening angle. In this system, the file or whetstone walks along a guide. As a result, in contrast to sharpening with hands on a stone, in which the hand inevitably changes the angle, making the approach round, in the sharpening system the angle is always the same. As a result, peeling off the excess surface is eliminated and, firstly, productivity increases markedly, and secondly, the result looks more accurate.

Abrasive- the working part of the main sharpening tools (bars, discs, sandpaper, ceramic mousses). It can be presented in the form of a powder, mixed with something in the form of a paste (for example, GOI paste), cemented with some kind of binder in a bar, glued to paper (metal plate, fabric). Also abrasives are part of natural whetstones. For example, many types of shale are sharpened due to the content of quartz crystals. Depending on the type of abrasive (Elbor, diamond, boron carbide, silicon carbide, chromium oxide, aluminum oxide, quartz, etc.), and the size of the crystal (grain), the abrasive properties of the tool vary.

Sharpening of knives and other tools begins with a coarse abrasive, gradually moving to a finer one. I think the best is to double-triple the grain size. For example, after a grain of 200 grit, go to grain 400, then to 800 grit, etc. Everyone will determine for himself what sizes to use (for example, 240 => 500 => 1000, and possibly continue 2000 => 4000, etc.) etc.). It depends on what size you want to finish sharpening and what kind of abrasive is available. I decided that enough sharpness to stop at was achieved with 800 grit. For kitchen knives that are constantly undergoing cruel tests, like cutting on ceramic plates, there is no point in fiddling with a finer sharpening, since you can spend a lot of time sharpening, then chop a tomato on a plate and get a knife that is blunt on a plate. So, for universal kitchen knives, I determined the sharpness obtained on a stone of 800 grit is sufficient. And I determined the rest of the dimensions from this representation, dividing (for preliminary sharpening) or multiplying (for finer refinement) the values ​​by 2 and choosing from the available assortment the values ​​that are closest to the division obtained. It is the step size that is important. For example, a one and a half step will take quite a long time to align the furrows left in the previous step, and then the same amount of time in the next step. Each step one and a half will consume the same amount of time as each double step. The quality will not change. Only time will change. Moreover, there is a possibility of unnecessary metal removal. If you take a step too large, for example, after 220 go to 800, the furrows from the coarse bar will have to be leveled so thin for a very long time. As a result, in order to achieve the same quality, with a large difference in grain size in each step, the time costs will have to be increased.

If you want to get the job done quickly, not at the expense of quality, choose the right tool, and in terms of grain size, choose the right abrasive step.

In other matters, it's okay if, in the absence of an intermediate abrasive, you switched from 180 Japanese grit to 800. The work will just take a little longer, and the wear of 800 stone will be a little more. But, on the contrary, adding a lot of intermediate ones, for example, 240, 320, 400, 600, you will not only increase the time spent, but, most likely, remove too much metal. In this example, it is better to insert 1 stone at 320 or 400 grit, although it is possible not to insert anything, just slightly increasing the processing time.

In conclusion, about abrasives, I want to note that if you do not make knives yourself, but only sharpen the existing ones, using an abrasive rougher than 400 Japanese grit (European standard F280, grain 36 microns.), You need it, just in case. But for work requiring an abrasive coarser than 400 grit, it is better to use not a bar, but an electric sharpening machine. Thus, the bars usually sold for sharpening knives are just not suitable for her. They can only perform preparatory work before sharpening knives. And they are sold everywhere just because they are cheap. An ordinary buyer cannot be convinced that he needs to buy a stone 5 or even 10 times more expensive. He would prefer to take a block for a dollar and not delve into the intricacies of sharpening skills. Accordingly, there is no one to sell normal sharpening stones for, and therefore there is no need to supply them for sale. In addition, for most sellers, whetstones are only related goods, in which they understand no better than ordinary buyers.

Stone(bar) - an abrasive connected by some cementing bond. At home, you can get it by mixing cement with quartz sand. However, industrial stones are made from more sophisticated bonds and abrasives. For a grindstone, it is of great importance what bundle it is made on. For example, diamond stones are often made by electroplating a diamond to a metal plate. Such bars very aggressively peel off the metal, as they have strongly sticking out sharp and very hard diamonds. They are well suited for forming slopes on a plate while turning it into a knife and for restoring a badly killed knife. They are also the only method for sharpening ceramic knives. However, under excessive pressure, diamonds can be pulled out of the bond, which leads to baldness of the bar and the loss of its sharpening ability. In addition, diamonds cut deep grooves in the metal, which, if not aligned, will quickly dull.

Some abrasives are not very strong and quickly become dull when rubbing against the metal that is sharpened on them. To prevent the bars from losing their abrasive ability, brittle abrasives are often kneaded on a soft bond, which gradually grinds off, allowing the worn out abrasive to crumble and reveal a fresh, not yet worn out abrasive. This is how, for example, the Japanese synthetic water stones Naniwa Professional (formerly called Chaucer) are made. However, the disadvantage of these stones is their rapid depletion, leading to thinning of the stone and the formation of pits on them, which do not allow sharpening normally. As a result, stones with a soft bond, although they retain their abrasive ability, need to be systematically leveled (on glass, another stone, or even on a road curb). It is good to sharpen very hard steels with such stones, as they will never become blunt. Also, they will not lead to edge chipping, since overpressure breaks down the bond of the bar, and not the sharpened steel.

Stronger abrasives are often held together with a stiffer bond. The toughest is ceramic. The ceramic bond is of 2 types: ceramics and glass ceramics (vacuum-tight ceramics). In ceramics, the bars are brought to a temperature where the clay begins to sinter. And they are called ceramic-bonded bars. Glass ceramics are produced at much higher temperatures, at which the clay turns into glass, in a vacuum environment to remove bubbles. They are usually called not vitrified bonded sticks but ceramic sticks or super hard ceramics. Ceramic bars practically do not wear out, but their price is not low, and their range is not great, since not every abrasive can withstand the glass transition temperature of ceramics. At the moment, corundum (aluminum oxide) is used in ceramic bars, as it can withstand the required temperatures. Therefore, the bars are often called aluminum ceramics. Also, in glass-ceramic bars, ruby ​​(a type of corundum), zircon, cubic zirconia, chromium sesquioxide, boron carbide, silicon carbide can theoretically be used. The disadvantage of glass ceramics is its high hardness. Excessive pressure on glass ceramics can cause chips on the edge of a knife made of brittle steel. If you press too lightly, the speed of work decreases.

Some bars are made using an organic bond (Venevsky Diamond Plant, Naniwa Super Stone, and others).

How rough or fine a whetstone will work is determined by the height by which the tip of the abrasive rises above the rest of the stone surface and the distance between the tips of adjacent abrasives. In synthetic (artificial) stones, this is almost always determined by the size of the abrasive grain filling it. However, in some cases, the grains grow together and intertwine with each other (typical of quartzites), or fused into each other (glass ceramics), that the distances and heights depend on the degree of accretion (fusion). In this case, they say that the stone wears away not with grain, but with structure.

Suspension- gruel from abrasive and water (oil). Either it is induced from powder (or nagura), or it is formed as a result of grinding off a stone. The presence of slurry on the stone will usually speed up sharpening, but can make it harsh when working on very thin stones. And the thickening of the suspension on thin stones leads to a relative dullness of the edge (relative to what could be obtained on a clean stone).

Nagura- volcanic tuff (natural nagura), containing abrasive grains and a very soft bond, comparable to the strength of chalk, as a result of which it is used as a stone for slurry. Thanks to the suspension from nagura, it is possible to increase the roughness and aggressiveness of a thin stone, or to increase the performance of a stone of the same grain size as nagura. Due to the very high cost of nagura and the fact that it only slightly speeds up the process, outside of Japan only special connoisseurs use it.

Naguru can also be used to clean the bar from salting or as an independent bar. But in the case of using nagura as an independent bar, its wear is very great. It's cheaper to buy new knives than to sharpen at nagura.

Sludge- abraded metal.

Coolant(cutting fluid) - There are 2 main types of cutting fluid used in sharpening: oil and water. They are called lubricating-cooling, because in sharpening, drilling, cutting materials with machines such as an electric grinder, drill, grinder, mechanical saw and others, local overheating occurs, leading not only to a loss of material properties (hardened steel loses hardening), but also destruction of material and tools (locally overheated glass breaks, diamond abrasives ignite when heated above 800 degrees). There is a need to cool the area of ​​contact of the tool with the workpiece surface. Also, to reduce wear, it becomes necessary to lubricate.

When sharpening without the use of machine tools, the cooling capacity of the coolant does not matter, since critical overheating without high speeds is unlikely. However, lubricity is still important.

Actually, the process of sharpening a knife

If you are making a new knife from a plate, grind it sequentially on stones 120 and 240 grit, creating descents on it and removing so much metal that, as a result, on each bar the end becomes twice as thin (it is, of course, easier to start with an electric grinder). After 240 stones, the butt should have a thickness of the order of a millimeter. Then grind the resulting workpiece with sandpaper or thinner blocks, thus obtaining a very blunt knife.

On a very blunt knife or a knife with a damaged edge that needs to be corrected (if the edge is bent, it is advisable to straighten it with the butt of another knife or musat before sharpening so that it does not scratch the grindstone and does not break out), it is necessary to form a cutting edge with a 240-400 grit stone, making an approach. In this case, a burr should appear on the edge. This burr will indicate that the edge is completely machined and you can proceed to the next stage.

Before moving on to a thinner stone, you need to remove the burr by moving the knife with the butt forward, as if you were guiding the razor on the skin, over a piece of wood, or, in extreme cases, over the same stone without pressure (another way to remove a burr is to change the sides of the knife with each pass).

Starting from 400 grit, the burr must always be removed when moving to the next stone or when finishing sharpening.

Sharpening a knife on a 400 grit stone, you get a knife of medium dullness, which, however, can start to shave uncertainly. You can stop at this, but the edge will not be durable and will quickly become dull. And the sharpness is not enough for delicate work. Therefore, I recommend switching to a bar of 800 grit.

800 grit is a stone for sharpening a not very sharp knife. After receiving and deburring this stone, you get a knife that shaves uncertainly and has a relatively stable edge. For many kitchen knives, this is enough, because as soon as they are cut on a plate, they will blunt, regardless of the edge resistance (the hardness of the plates is much higher than the hardness of steel). However, if the knife is used only for cutting on wooden boards, or it is a chisel that requires the highest sharpness and durability, you need to sharpen it on a stone of 1500 grit.

1500 grit is the limit for the classic European kitchen knife (but not for the chisel and planer blade). After removing the burr, the knife will shave well without scratching, chop tomatoes without crushing, and it will be nice to keep sharp.

But if this is not enough, sharpen 3000 grit and higher on a bar. As a result, it can be brought on the skin with GOI paste. But the skin should not hang loose. Due to its softness, it flexes under the edge. A pit is formed in the skin, giving the edge of the knife a large radius and, thereby, blunting it. Ideally, the leather should be firm and glued to a wooden base to form a leather whetstone.

In other words, after stones of 10,000 grit and above, a leather block is not needed. But these stones must be perfectly polished. Due to the laboriousness of this task and the high cost of fine-grained stones, many people prefer leather.

To sharpen quickly, you need to take the right block. For example, a 60 grit diamond in a minute will give the plate the shape of a knife, but a fine-grained corundum block will not cope with this in an hour. Therefore, it is very important to choose the right grain and aggressiveness for a specific task. Coarse grinding of hard steels can be accelerated with a diamond. Priority for mild steels: corundum, boron carbide, silicon carbide. It is good to use a sharpening system for this. It will not only make the work more accurate, but also, by eliminating unnecessary processing, will reduce time costs.

I do not recommend trying to get an invisible edge with a coarse abrasive. Especially with a diamond. Coarse abrasive creates deep furrows. If, after sharpening, these grooves remain, the knife will cut perfectly, but it will also quickly become blunt as the teeth formed by the grooves break. What's more, deep grooves can lead to cracks and chips.

In order not to remove excess metal from the knife, with abrasives from 200 grit and coarser, it is better not to make slopes thinner than 1 millimeter at the end and not to grind the cutting edge if it does not require alteration.

With a bar of 400 Japanese grit, you can bring the slopes to 0.8-0.4 millimeters and shape the cutting edge so that its end is invisible to the naked eye.

An edge is never perfect, consisting of a line one atom thick. There are thousands or even millions of atoms on the edge. They form a rounding of the edge. The smaller the radius of this rounding, the sharper the knife. But the abrasive always pulls out metal particles as it moves away from the edge and drives them inward as it moves to the edge. The size of these particles is comparable to the size of the grain. As a result, if you go to the edge with a rough stone, it will leave teeth with relatively sharp tops and blunt bases. To increase the sharpness, you will first have to grind off these teeth to the bases, thereby reducing the size of the knife. The thinner the abrasive, the thinner both the tops of the teeth and their bases. The smaller the corner radius and the sharper the knife. Therefore, in order not to reduce the size of the knife, you do not need to go to the edge with a rough stone. You need to go to the edge with bars that give an acceptable sharpness, those on which, in principle, you can finish sharpening (for example, a 400 grit knife cuts quite well).

The knife will cut easily even at large sharpening angles if it is cut on a very fine stone. Due to the large angle, it will slightly jam (dull) when colliding with solid particles, and thanks to the finish on a thin stone and small size of the teeth, the teeth will break less when cutting (blunting the knife). Thus, setting the knife to a relatively obtuse angle, but tinkering with it on thin stones, you can get a knife that will cut frozen meat and fish bones, without jamming and without losing sharpness, but at the same time, and cut tomatoes well. For these operations, of course, it is better to have different knives. However, thin stones, increasing the time spent on sharpening, not only increase the durability of the knife, compensating for the time spent, but also increase its versatility. Obtuse knives begin to tackle delicate tasks, while sharp angled knives are less afraid of rough work.

When trying to increase edge durability, it is important not to overdo it. Our kitchens are dominated by mild stainless steel knives. For example, the commonly used Tramontina wood-handled knives have a hardness of 52 HRC. When sharpening such a knife up to 10 thousand grit, the edge becomes much thinner than hair thinner than any foil. With such a thickness and such soft steel, it bends and smoothes, almost from the breath of the wind. If you cut with pressure, the knife will do a good job of cutting and shaving (until the edge bends). But if you cut it by pulling, it will slip (soap) because of the smoothness. And it turns out that the same knife, sharpened for 1500 grit, cut by pulling better due to a relatively large saw on the edge, more resistant to smoothing. And the time for grinding up to 10,000 grit is spent a lot. And it is more difficult to control such a fine sharpening, since due to the microscopic dimensions, it is no longer clear either by eye or by touch, whether the edge is well machined with the next abrasive. But it turns out that the time was wasted, and at the initial stage the knife cut better. Plus, you need to take into account the thread on the plates, which kills sharpening in one movement. So, in each specific case, you need to determine your reasonable limit, and not mindlessly sharpen up to 20 thousand grit with a Suehiro Gokumyo GMN200 stone for $ 250 just because someone wrote so on some forum.

It is important that during sharpening on thin stones, in order to avoid enveloping the metal on the edge and the formation of craters, the knife must be moved with the tip in the direction of movement or, at least, with the tip in the direction of movement, including (that is, in extreme cases, if otherwise inconvenient, sharpening back and forth). On coarse stones, it is also better to move the point forward in order to quickly expose the middle (edge). However, after sharpening on rough stones, it may be useful to make a few strokes from the direction of travel to break off the microburrs.

Time spent

With the correct selection of the bars, sharpening even a badly killed knife to a razor sharpness, even without a sharpening system, will take only a few minutes.

Don't listen to people sharpening a powder steel knife almost as hard as diamond on Japanese water stone or Arkansas. Diamonds are sharpening diamonds!

Do you want to spend a week sharpening?

Do you want to level the bars on the glass with silicon carbide powder for several hours after that?

Do you want to spend a few salaries on unproductive bars?

If yes - full speed ahead, natural stones, Japanese watermen ... and be patient.

Other gurus offer to sharpen everything with Venev diamonds on an organic bond. They can be understood: why, in our technological age, hold on to the technology of the Stone Age? Down with natural stones, down with too troublesome Japanese water workers! A few minutes and the knife is sharper than a razor!

But it's expensive. And, in fact, the cutting ability and blunt resistance of a knife will not be ideal.

For those who are not ready to spend half their salary on sharpening stones, there is at least technological solution: electroplated diamonds for coarse sharpening, fused alumina, boron carbide and silicon carbide in the middle of the path (but finer-grained diamonds are also possible), alumina ceramics or natural stones at the final stage.

That is, the combination different types most suitable for specific operations.

The speed is about the same. The cost is several times lower. Instead of carbides, stones of various types of corundum can be used. Slightly slower work, update stones a little more often, but very cheap! The main thing is the correct grain size, the correct pitch, and not to remove excess metal, not to try to get a finished edge on a too coarse bar. As the end of the edge becomes thinner, move to a thinner stone. You don’t have to remove the excess, you don’t have to waste time and grind the knife.

Division of whetstones by type of coolant

Since there are 2 main types of cutting fluid (oil and water), in addition to the type of bond, the type of abrasive and the origin (natural or synthetic), it is customary to divide the whetstones into oil and water. Water bars do not need to be moistened with distilled water. As oil for different purposes is filled with different additives, so water can contain "additives". Any not too dirty water from the tap or reservoir will go for sharpening. To reduce its volatility from the surface of the bar (at manual sharpening) and increasing the ability to keep the sludge afloat, glycerin can be added to it. Detergent can be added to the bar to reduce the absorption of the slurry. These additives will not change the essence of the cutting fluid: water with "additives" will remain water.

The same can be said about oil: diluted oil or oil with impurities does not change its essence. Moreover, the word "oil" in this case should be understood broader than the usual ideas about it. First, the oil is composed of esters fatty acids and, for example, oleic acid, as if not being an oil, is an excellent cutting fluid, and secondly, instead of oil, you can use any oily or soapy liquid, be it kerosene, glycerin, or even a detergent (for lack of a better one).

Of course, the whetstones do not have to be used with exactly the type of coolant recommended by the manufacturer. But this will not do without negative consequences: Arkansas will clog up with sludge on the water and stop sharpening, the Soviet silicon carbide bar will be soiled by the oil soaked into it until the end of the day. Therefore, the bars are best used as the doctor ordered. And if you do this, peculiarities are found in the bars: the water bars release a suspension consisting of a free-rolling abrasive. From this they wear out more (than when used with oil), but sharpen faster. On the fine-grained blocks, another feature appears: the fine-grained oil sticks give clear strokes, smoothing out the metal around them and thus creating a mirror effect. In contrast, in water stones, the formation of clear strokes and smoothing is prevented by a cushion of suspension, which, breaking the contact of the bar with the treated surface, leaves its own short strokes and a matte effect.

Eventually stones in water generally work faster, while stones in oil will produce a highly reflective surface and a more aggressive cutting edge faster(due to sharper strokes on it, which is good for knives, but bad for razors). This ability is used by craftsmen: after working with a knife on a water bar with water, they finish on it in a dry one to obtain an average result between oil and water stones.

There are bars positioned as dry bars. These include vacuum-tight ceramics and diamonds in organic or galvanic bonds, as well as Naniwa Super Stone. However, vacuum-tight ceramics only with oil can be protected from contamination with sludge, and galvanic diamond plates lose speed if the sludge is not washed out with water. As a result, diamonds and Naniwa Super Stone work better with water than dry and should be classified as water bars, while vacuum-tight ceramics work better with oil and should be classified as oily.

For ordinary knives and knives made of steel that are prone to rusting, it is better to use oil stones. For knives with Scandinavian slopes, when sharpening without a micro-feed, it is better to use water stones, since wide slopes float in oil, almost without touching the adrazt. If you have to use an oil stone on scandispieces, instead of oil, it is better to use either a solution detergent, or a very thin oil or kerasin. In general, aquatic kainis are more versatile. However, some steels can corrode with prolonged sharpening of water and stones.

Do not sharpen soft steels with electroplated diamond stones. Diamonds will cut deeply into the steel and gradually break out of the bar. Diamond stones are designed for sharpening very hard steels that slide over ordinary stones without sharpening.

Do not sharpen very hard steels, such as chisels and quick cutters, with sticks on hard, such as vacuum-tight ceramics, bonds. The abrasive will gradually dull, but the bar will not be renewed, thus the bar will quickly lose abrasiveness. Alumo-ceramic bars can serve without wearing out for a long time, provided that very hard steels are not sharpened on them, so as not to render them unusable. Vacuum-tight ceramic bars are very good for sharpening relatively soft stainless steel, with a hardness of up to 58 (you can sharpen and steel a little harder, but the harder the steel, the more the bar will be smoothed).

Japanese synthetic water stones and their soft bond counterparts are suitable for most steels. However, many of them wear off relatively quickly (although there are also bars on a relatively hard bond). This abrasion causes renewal of the abrasive. Instead of a blunt one, a new, sharp abrasive appears on the surface. This is the reason for the universality of these bars: they sharpen any steel, as they are constantly updated. Thanks to the fast renewal, the stones are not greasy. But when grinded, they lose their shape, require alignment and are gradually consumed. Buying new stones, instead of worn off, is somewhat costly, and leveling out those that have lost their shape is troublesome. But, worst of all, many of the branded Japanese stones are demanding on drying modes and can crack when dried quickly. Keeping them wet, as is customary to do with Russian stones, is also impossible for many, since the most expensive Japanese synthetic stones are made on a gradually decaying magnesian bond. That is, when buying a Japanese synthetic stone, you need to understand very well how to work with this particular stone, the ways of using which can be very different from the ways of using other stones (including stones of the same company, but of a different series). Be especially careful with the bars glued to the stand. Due to the difference in the degree of deformation during swelling and the difference in the speed of swelling-drying, the bars glued to the supports tend to burst.

There can be no consensus on Japanese water stones similar to Naniwa Professional (formerly Chaucer). On the one hand, they are versatile and sharpen everything. On the other hand, they need to be wetted, but then dried very carefully so as not to sour and crack. They are clearly not as good as expensive. Needless to say, if sandpaper glued to a piece of moisture-resistant chipboard costs 4,500 yen! For rough work, they are often inferior in performance to wear-free and cheaper Venev diamonds (and even more so, galvanized diamonds), and for fine work they are inferior in performance to good specimens of natural stones.

But buying a Japanese is easier than buying a good one. a natural stone... Natural deposits are depleted, and Japanese synthetics are inexhaustible.

Natural stones have different properties and there is no general recommendation for them. They are of 2 types: some, in fact, are petrified silt with an admixture of silicon dioxide. Where silicon dioxide is an abrasive, and sludge is a binder. These natural stones are not fundamentally different from synthetic ones. Contrary to the popular belief that the concept of grain size is inapplicable to natural stones, silicon dioxide works according to its grain size, no matter how the stone is initially polished. Just keep in mind that the strength of silicon dioxide is significantly lower than that of synthetic abrasives, and it grinds quickly, giving a softer grinding. These stones work by releasing a suspension. Other stones, in particular, quartzite (black hard arkansas and arkansas translucent), are almost pure silicon dioxide, the crystals of which have grown together. Their grain size is determined not so much by the size of the crystals as by the degree of polishing of the stone.

Quartzites have unique properties. They are mounted not with glue, but with time. It will take millions of years to reproduce artificially.

As a result, each natural bar should have its own recommendations. But personally, I see no reason to use natural stones with a grit value below 1500. Diamond, silicon carbide, aluminum oxide (corundum), and often boron carbide, work faster and are better suited for quick metal removal.

Venevsky organic-bonded diamond stones have proven to be wear-resistant and sharpen any steel. But I would not recommend sharpening soft steels with them, so as not to increase their wear (because diamonds there are no less sharp than diamonds on an electroplated bond, and also, being bogged down in soft metal, can be ripped out of the bond). In addition, the manufacturers agreed that on fine abrasives, somewhere from 1 micron (about 10 thousand grit), the powder can clump uncontrollably, forming clots in the bar, leaving rough scratches on the treated surface. Thus, the question arises, will a 10 thousandth organic-bonded diamond block give a sufficient polishing purity? And in general, is this disease not peculiar to other artificial bars? Will synthetic bars on the order of 10,000 grit give the clarity of a good natural stone? Judging by the fact that large inclusions are sometimes found even in expensive Japanese synthetic stones, manufacturers of artificial stones cannot completely get rid of this problem.

Summarizing the information on the bars, you can offer options:

1. Correct selection of natural stones;
2. a set of Japanese water stones;
3. organic bond Venev diamonds;
4. a combination of electroplated diamonds for hard steels and ceramics for the rest.

The options are listed in order of cost and hassle of caring for the bars (the need to level and grind). Although, often, it is more troublesome to care for water stones than for natural ones. At the same time, Japanese water companies can be replaced with cheaper analogs and the option can be made the cheapest, but, nevertheless, very troublesome.

The speed of work on each of these options depends on the metal being processed, but in general, option 3 is the fastest, and option 4 is only slightly inferior in speed. However, after diamonds, even Venev diamonds, it is better to finish with a less harsh abrasive. For example, sharpening a knife with a hardness above 61 with galvanic bar up to 800-1500 grit, bring it to good resistance on 1500-3000 grit bars of aluminum oxide (corundum) on a relatively soft bond. And then, for maximum durability, bring 5000 grit and above on a good natural stone. Thus, both the maximum speed and maximum quality, and a very low price will be achieved (the price in comparison with sets either from pure Venev organic bars, or from Japanese high-quality synthetics, or from natural stones). An attempt to further reduce the cost of a set of stones will lead either to a loss of speed (sharpening only on cheap aluminum oxide bars), or to a loss of quality (sharpening only on diamonds with a galvanic bond), or to the loss of both at the same time.

Besides, speed is usually not important for kitchen knives. And the quality does not matter if the knife is immediately thrown into the sink, where it gets dents, knocking on other knives, forks and plates. And then cheap aluminum oxide bars are quite appropriate. And the grain size of 1500 grit is unnecessary. Sharpening such knives with a stone thinner than 800 grit is a waste of time. Edge durability will still be compromised by rough handling. Only if the attitude towards the knife is careful, there is a sense of its subtle refinement.

You should not buy thin Venev diamond stones with a low percentage of filling. By making a budget option, managers of the Venev plant are promoting it, claiming that neither in terms of speed of work, nor in quality, fine-grained bars with a low diamond content are not inferior to bars with 100% filling. However, at the expense of not high density diamonds, each particular diamond experiences more pressure during operation and cuts into the metal harder than with 100% filling, making the processing more rough. Thus, bars with 100% filling work more accurately. And if they seem too expensive, then it is better to think about electroplated diamonds or other abrasives.

For a visual representation of the difference in filling, hold 4 studs between your fingers to create a mini comb and scratch your hand with it. It might even be enjoyable. Then try scratching with one nail. This is unlikely to be pleasant. This is the difference between Venev bars 100% and 25% filling. 25% of the bars hurt the metal! Of course, diamonds do not stick out of the bar like nails, and the effect is not so terrible, but, nevertheless, 100% sharpens the bar faster and better.

Starting from 8 thousand grit, the bars do not so much sharpen as they smooth the metal (but for this they must be well polished, otherwise they will work much rougher than their gritness suggests). So if you don’t need a mirror surface, then you don’t need high-density bars. They will not sharpen. Their task is to level out the smallest irregularities that accelerate the dullness of the knife.

In addition to choosing the type of bar, it is of great importance correct selection of grain size... If the knife stops chopping tomatoes, but cuts them well, you need to start sharpening it from about 1500 grit. If the knife cuts tomatoes poorly - 800 grit. If the knife cuts very badly - 400 grit and coarser. You do not need to start sharpening a slightly dull knife with a coarse bar. This will not achieve more sharpness or speed, but more wear on the knife. It is better to sharpen a little longer with a thin bar than unnecessarily grind off the steel with a coarse one. In addition, smoothing furrows from a rough stone may take longer than sharpening directly on a fine stone.

The hardness of the bond and the density of the abrasive particles are also of great importance. The hard block does not lose particles and if the tips of the particles are cut off, the abrasiveness is reduced. In rough stages, this has a negative effect on speed. But in the middle stages, especially at high particle densities, it can be used to give a bar with a relatively coarse grain to give a smoother surface. This is sometimes used to make Translucent or aluminum ceramics give a thin razor finish. This is often used, rubbing different sides of the stone on powders of different grain sizes, in order to sharpen quickly on one side, and finely finish on the other. But this feature should be taken into account just when selecting stones. For example, after a hard stone at 800 grit, the knife will be sharper than after a soft stone at 1500, although the strokes after 1500 will be thinner, and the surface finish and durability are higher. In this regard, it is often said that it is impossible to compare the gritness of natural stone (usually having a high hardness and quickly grinded, polishing abrasive) or glass ceramics, with the gritness of a synthetic stone. But this is a simplified approach that interferes with understanding the physics of the process. Generally speaking, different stones cannot be compared in terms of grit at all. A soft aluminum oxide stone will work completely differently than a hard diamond stone with the same grit. The hard silicon carbide stone will also give its character of work. And on a soft silicon carbide stone, you get the 4th option. And all with the same grain size. Grit is only one of the guidelines for abrasive ability. Ligament hardness is another guideline. Soft stones work faster with the same type of abrasive, while hard stones give more sharpness. Accordingly, for the initial stages, if the wear rate is not critical, soft stones are preferred. And for the finish, hard ones are better suited. For example, sharpening a razor to 3000 grit is good on soft ones, and then go on to hard ones. And a kitchen knife, on which you are not going to spend a lot of time, you can finish on a hard stone of 1000 grit. However, it can turn out to be sharper than brought to 3000 grit on an expensive, but softer Japanese water stone. That is, by choosing the correct hardness, you can get an inexpensive sharpening set that gives the same sharpness as a large and expensive set of stones with poorly selected hardness (but you need to take into account that the hardness of the bond provokes salting).

The density of particles is almost always the better, the higher. Only if it is necessary to loosen the surface is the low density useful.

Quartz widespread in nature in the form of sand, sandstone, quartzite, etc. Due to its relatively low abrasive ability and strength, it is practically not used in synthetic whetstones. Quartz is an abrasive for grindstone, which is petrified clay mixed with silica dust. It does a good job with classic steels. But not effective for powdered ones.

Corundum(Electrocorundum) due to the relatively low abrasiveness due to the rounded shape of the grain (partially compensated by alloying and, for example, chromium electrocorundum - technical ruby ​​- has sharper edges), does not very effectively remove hard metal at normal pressures. But, having high strength (for example, in relation to brittle silicon carbide), it retains its abrasive ability for a long time. When used on fine grained hard bond bars produce inexpensive wear resistant bars. And when used on coarse-grained bars, it can increase the processing speed of mild steels by increasing the pressure (for rough processing, an increase in pressure is acceptable, but the silicon carbide would crumble at the same time, without allowing an increase in speed). In general, corundum bars are the most unpretentious and are usually used for sharpening stainless steel knives.

Carborundum(translated as "green carbon stone" or silicone carbide), having an average abrasiveness and low price, it is used in sandpaper and grinding powders, allowing to quite effectively remove metal of various hardness and viscosity. However, it is afraid of pressure and collapses into small particles, losing its ability to quickly remove. Therefore, in coarse operations it is often replaced with cheaper corundum, which makes it possible to increase the processing speed by increasing the pressure. Due to its low deformation strength, it quickly wears out when processing ductile steels. And, despite the general versatility of silicon carbide, it is more practical to use corundum bars for sharpening stainless knives. However, the rapid wear of silicon carbide (as well as silicon dioxide) has a positive effect on fine-grained bars: grinding on a suspension obtained by breaking crystals gives a cleaner surface. Therefore, fine finishing and grinding, all other things being equal, it is better to do not on aluminum oxide, but on silicon carbide or silicon dioxide - quartz.

Boron carbide according to the table has a fairly high abrasiveness. However, it should be borne in mind that this is an indicator of the amount of glass worn out when 1 gram of free-rolling abrasive is worn (in relation to the amount of glass worn out by the same mass of diamonds). Since boron carbide is light, there will be one and a half times more abrasive particles in 1 gram than that of electrocorundum. Therefore, when comparing the operating speed of 2 bars of the same size, one of which is boron carbide and the other is aluminum oxide, the relative abrasive ability of a boron carbide bar should theoretically be one and a half times less than expected from the table. In addition, the ability to abrade a large number of glass, for boron carbide is determined not so much by its cutting ability as by its wear resistance more than 2 times higher than that of electrocorundum. Boron carbide does not wear out longer, due to which it surpasses electrocorundum in "relative abrasive ability". In fact, if we compare the wear time of abrasives and the result obtained, the speed of boron carbide will be lower than that of fused alumina. This happens because boron carbide does not produce sharp edges during crushing. But it has high strength, maintaining the specified abrasiveness for a long time. As a result, it is usually used not in bars, where it would be superior to cheaper aluminum oxide only in wear resistance, but in the form of powders and pastes for finishing cutting tools made of superhard materials such as tungsten carbide and titanium carbide alloys (where corundum and carborundum would quickly wear out). However, boron carbide can be used in bars for mild steels, which can be processed without blunting. Due to the high wear resistance of boron carbide, such bars are logical on a very hard bond. The hardness and grain and bond result in very wear resistant whetstones. But this creates the problem of salting, since the layer clogged with sludge itself does not crumble. Accordingly, when using a hard-bonded boron carbide bar, you should try to prevent salting, and if it happens, refresh the bar by cleaning or peeling off the clogged layer. It was these complexities and the limitation to only mild steels that made the boron carbide bar unpopular. However, when other types of bar are available, hard bond boron carbide bars can be used on mild steels to reduce overall bar wear and thus reduce the cost of sharpening in the long term. Moreover, due to the combination of high hardness and roundness of the shape, boron carbide well removes metal, ruffled with a coarse abrasive, leaving a smoothed surface. This allows you to start sanding immediately after roughing, reducing grinding time and reducing the need for medium-grained stones.

Experience shows that boron carbide is effective on steels up to 55 HRC. That is, it works well on almost all cheap stainless knives, including the cheap Tramontina series. But on the Tramontina Professional Master and more expensive Tramontina knives, its effectiveness drops noticeably. That is, depending on your knives, it can be either an eternal, indestructible bar, or a useless bar.

Diamond(mainly synthetic), having high hardness and strength, cuts metal like plasticine. Due to the high cost, to obtain a bar, it is usually applied to the plates in the thinnest layer. But from this layer, grains of diamonds are pulled out by viscous steels. Therefore, it is most advisable to use for processing very hard steels and ceramics, which are difficult to process with other abrasives.

Elbor(cubic boron nitride) is almost as hard as diamond. In addition, it has good chemical resistance and can withstand temperatures higher than diamond, which allows it to be used for fast cutting and grinding, significantly increasing the processing speed on machine tools. In manual processing, where there are neither high temperatures nor contact with aggressive media, it does not have any special advantages over diamonds, and therefore, due to the cost exceeding the cost of synthetic diamonds and low abrasive ability, use in sharpening stones is not economically justified.

Marking of grindstones made in Russia

A - electrocorundum

C - silicon carbide

V - ceramic bond

B - bakelite bond

I would like to note that the manufacturers of Venev diamond bars claim that a grain of 1 micrometer corresponds to 12-15 thousand Japanese grit. But this is not the case. 12-15 thousand grit is already a fraction of a micrometer. However, regarding the bars, the statement of Venev manufacturers may be true, since in a 1/0 bar the particle size is less than 1 micron, which means that the bar can really have 12-15 thousand grit.

I also want to note that the type of operations performed is indicated conditionally, since everyone determines for himself which grinding is fine for him and which is rough. In addition, by varying the type of abrasive, type of lubricant and pressure, it is possible to increase metal removal for fine-grained blocks or achieve finer work from coarse-grained ones. So, the operations performed are indicated only for an approximate idea of ​​the purpose of the abrasive of a given grain size.

In all descriptions I use the Japanese system, since the grain size is in microns, almost no one indicates, and the Japanese grit system is commensurate with the grains. That is, in a Japanese stone 800 grit, the grain is 2 times smaller than in a stone of 400 grit. And in the Russian F400 (corresponds to the Japanese 800 grit), the grain is 3 times finer than in the F220 (although the F value would suggest about a twofold difference). Thus, only in the Japanese system does the value correspond to the size (such is the pun). For the European system, it would be more convenient to simply indicate the grain size in micrometers. Even more confusion in the European standard is introduced by sandpaper, which, unlike the bars, is marked as "P" and has its own gradation of grain sizes, which does not correspond to the gradation in the bars.

Approximate grit sizes of the most recognized whetstones (Spyderco alumina ceramics and natural Arkansas):

According to this table, the Spyderco Aluminum Ceramic Kit is a complete kit for sharpening not too dull knives to near razor sharpness. Unfortunately, Spyderco does not offer a rough version. Together with it, the kit would allow you to quickly sharpen even very blunt knives. But, alas, they don't have the coarse option. But the Arkansas set is even presented too full for sharpening (some of the stones can be excluded). However, due to the fact that it is a natural stone, its speed of work may be inferior to aluminum ceramics. Thus, the price / quality ratio of Arkansas is not justified even in relation to the expensive Spyderco. The exceptions are the Translucent stones, which, judging by the reviews, can be polished up to 6000 grit and higher, and Black Hard, which, thanks to the close intergrowth of crystals, sharpens 8-10 thousand grit, and quite quickly. These stones are considered to be the best for sharpening knives before switching to leather with paste. In this segment, with Arkansas, perhaps only the Chinese ruby ​​ceramics can compete, which, judging by the reviews, can be polished to the same degree, having received a cheaper analogue. Other fine-grained counterparts do not compete in either speed or durability.

It is also clear that at the moment there is no point in acquiring Norton India and Norton Cystolon, since in any city it is easy to find the same rough stones 20 times cheaper. Probably there will be a different level of quality. But for such rough work, quality does not matter. With such a striking difference in price, for such rough work, only the price and ease of use matter. In the red and purple areas of the table, you can ignore the quality of the stones. Roughing on Stayer is as good as Roughing on Norton Cystolon. However, as the grain decreases, the requirements for the quality of the stone begin to increase.

) In particular, GOST determines in which 4 sieves of different sizes how many percent of the grains should settle. As a result, to determine the size, you can take the maximum possible grain size (but such large grains are only a couple of percent and they will give only individual scratches), the size of the average of these 4 sieves, or the average size of the main fraction (but not the main fraction can be contained in enough large quantities to determine the nature of the processing). In fact, none of the options will provide a precise definition. But even if all the grains were exactly the same size, the abrasiveness would depend on the abrasive substance, the type of bond, the cutting fluid (coolant), the hardness and viscosity of the material being processed (which is not directly related to the abrasives themselves, but is closely related to the substance , of which the abrasive consists). Pressure is equally important. At high pressure, the diamond cuts to the full possible depth, and the silicon carbide simply crumbles. As a result, diamond stones work harder than carborundum, faster on hard materials, but usually slower on viscous materials. So, even within the same size, the nature of the work of different bars is different. Let's add here different percentages in different sieves for different standards and we will get a possibility of only an approximate comparison of standards.

) Naniwa Professional Stones are not produced below 400 grit. Since it is believed that below 400 grit, the quality of the stones is not important. And on this page it says that 400 grit is the roughest stone you need to sharpen. Coarser stones are needed either to change the sharpening angle or to fix a chipped knife. That being said, this page states that 1500 grit is an upper limit for many needs and provides a sharper edge than most new knives out of the box.

The Suehiro website says roughly the same thing. Namely, the main sharpening of kitchen knives is done on stones of 320-800 grit, and the final adjustment is made for 1000-1500. Sharpening on finer-grained stones, according to Suehiro's experts, is not required for kitchen knives.

As you can see, the opinion of Japanese experts does not completely coincide and, in part, is determined by the taste of specific people. But if to generalize, then their opinion converges on the fact that for sharpening kitchen knives, stones of 400-1500 grit are required. Coarser stones are needed if the knife has received severe damage, and thinner stones are needed for specific purposes (for example, for carpentry tools).

The knife, no matter how good it is, begins to dull over time. And, consequently, each of its owners sooner or later faces the need for sharpening. Currently, there are several options for solving this problem: using an electric grinder, a mechanical grinder, and manual sharpening with whetstones... The last method is the most common. This is due to the fact that sharpening with the help of bars is one of the simplest, but at the same time, high-quality options for bringing the cutting edge of the knife to the required sharpness. When working with bars for sharpening knives, remember the following points:

• It will be easier for beginners to operate with bars, the length of which will be equal to or greater than the length of the sharpened blade;
• Full, high-quality sharpening is carried out using three types of stones, with varying degrees of grain size. It all starts with stones with a large grain and gradually ends with fine-grained bars;
• When working with sharpening bars you must use a lubricant. Its role is played by both ordinary water and special oils;
• For daily dressing of the cutting edge, musat is required. Musat resembles a file in appearance, with ribs parallel to its canvas. It is used to optimize the sharpness of the blade. And also the cutting edge is corrected, after its contact with excessively hard materials.

Ceramic sharpening stones

Ceramic bars are a rather controversial product. Despite their positive traits(good surface finish and durability), they are inferior to other types of bars in a number of parameters. First, sharpening with a ceramic bar will be very slow and time consuming. Secondly, it is very difficult to find a fine-grained bar in modern realities. But ceramic sharpening stones relatively cheap and unpretentious to use (there is no urgent need for lubrication, although its use will extend the life of the bar). Such sharpening stones are usually used for frequent fine dressing and debugging, sometimes such a bar can even replace musat. Ceramic bars are produced not only for sharpening ordinary knives, but also for finishing serrated sharpening, fish hooks, and needles. There are a large number of ceramic whetstones on the market, produced in Poland, China and Germany. However, there are still products of the USSR, such bars can be bought without hesitation and can safely count on the excellent quality of the product. Since ceramic stones are relatively cheap, if the integrity of one bar is broken, it is easier to go and get a new one than to pore over leveling the old grindstone. But for the most economical, there is just a way to bring the old bar to its proper form: it is necessary to regularly rub the bars against each other under a stream of warm water.

Japanese water stones

Among the advantages of Japanese water bars are high quality metal processing and high speed of work. And although japanese sharpening water stones, of course, a good thing and useful in the household, but not for beginners in business. First, water stones are expensive. Very expensive. Secondly, they are whimsical to use: working with sharpening water stones requires constant lubrication, pre-soaking before use and thorough drying after sharpening (this applies to fine-grained bars). It is recommended to store coarse-grained and medium-grained stones in water, which must be regularly changed and decontaminated. Water stones stand out for their softness and, consequently, their grinding speed. The thinned stone can be glued to a piece of wood, thereby extending its service life to the maximum possible level.

In addition, water stones of natural origin tend to grind unevenly, which leads to sad consequences. To bring the grindstone into working condition you will have to grind and level its surface. Unlike ceramic stones, which, as mentioned above, can simply be periodically rubbed against each other under running water, Japanese bars will require a whole procedure. In short, the process will be to find a suitable smooth marble or glass surface, cover it with waterproof sandpaper (pre-moistened in water) and with methodical movements, slowly edit the block, sliding it over the skin.

Diamond whetstones

Diamond Bars are often produced not only as a separate tool for sharpening, but also as an integral part of some kind of grinding machine. Therefore, you can find diamond whetstones on sale in a wide variety of shapes and sizes. Moreover, periodically complete with diamond stones all kinds of fasteners are supplied for sharpening.

The bars produced by the American company DMT have won a good reputation. Typically, such bars are a metal (and sometimes plastic) base, on which a diamond pattern is sprayed. Diamond abrasive grains are held onto the substrate surface, usually by electrolytically deposited nickel or copper. Diamond bars are very durable, they just take a while to get used to. All unreliable grains crumble and the whetstone takes on its normal shape, designed for a long time of high-quality work.

Sharpening stones like these are just what a beginner will do. They are affordable and easy to use. When working with them, lubrication is desirable, but not at all necessary. Water or soap solution plays its role here. After sharpening, the diamond block just needs to be thoroughly rinsed and removed to a safe place. Diamond whetstones wear-resistant and provide a high rate of work. The reverse side of the coin here is the possibility of irreparably damaging the cutting edge, with a careless quick sharpening. Diamond bars never lose their flat working surface, they do not need to be straightened. Such sharpening stones are not afraid of falls and bumps. It is extremely difficult to damage the working surface of a diamond bar. To do this, you need to attach special effort and persistence.

Natural sharpening stones

There are a great variety of natural stones suitable for creating whetstones... Among this variety of materials, the "Belgian stone" is distinguished, which is a fine-grained muscovite shale and Arkansas stone (quartz), as well as different kinds slate. Arkansas stone has a unique structure. It can rightfully be considered the finest-grained and homogeneous rock with amazingly strong bonds between grains. You can work on such blocks only with the use of grease. The most common lubricant is mineral oil. If this is neglected, then the entire working surface of the grindstone will very quickly become clogged and become unusable.

Natural stones do not always outperform artificial stones. If only because the abrasive grains in them may be far from homogeneous and tend to fluctuate greatly in their size. The optimal length of a bar made of natural material is 20 centimeters or more. Good natural whetstones are expensive to their owners. Moreover, most often, an artificial analogue is more durable and effective. Natural whetstones are very fragile and will likely need to be sharpened and smoothed by hand when you just bought a stone.

This review continues my series of reviews of various knife sharpening bars. Today we will talk about a diamond bar from the Venevsky diamond plant for sharpeners of the Apex type.

As usual, the review is presented in text and video versions. The video is attached at the end of the review.

WHAT IS THIS
By themselves, Venev diamond stones are widely known and are popular among sharpeners. The Hansa has a large topic dedicated to them, they are mentioned in many topics related to sharpening.

But this format is new. Until now, Venev bars have been produced in the format for manual sharpening in three sizes:, and. Users of the Apex type sharpeners have adapted to sawing these blocks and using them in sharpeners. This procedure is quite doable at home, albeit with certain problems. True, a bar 200 mm long does not fit into a standard mount, so two options were used: either shorten the bar, or remove the mount from the guide, holding the bar with your hand. Bars with a length of 120mm have their own minus - shorter length. But all these difficulties paid off with the performance of the bars and their acceptable cost, especially given the fact that the bars are double-sided. From time to time, a regret-wish was expressed on the forums: "Oh, there would be forms especially for the sharpener!"

And then there were bars, created specifically for the sharpener, with the appropriate mounts and standard size 150X25. Hooray! Finally. But then a dilemma arose. It turned out that a sharpener bar costs about the same as a standard bar, and even more. You can buy the hero of the review for 1180 rubles or a bar 120X35 for 900 rubles or a bar 200X35 for 1132 rubles. And this despite the fact that standard bars are double-sided, i.e. these are two stones in one. This alignment led to the fact that people thoughtfully scratch their turnips and think what to prefer - the convenience of work or economy? There is no definite answer, everyone sets priorities for himself.

WHY
Today, there is a steady trend in the knife industry: hard steels are becoming more widespread. Moreover, the point is not only in hardness as such, but also in the fact that carbide-forming alloying additives are widely used, primarily vanadium.

Not so long ago, a person accustomed to sharpening a banal stainless steel was often confused by D2 or P6M5 and had to hear “this knife cannot be sharpened! The stone wears out, but at least henna for a knife! ”, But there is only a maximum of 2.1% vanadium. Today, people are unanimously turning up their noses from steels that are below S30V and a hardness below 59HRC, and S30V with its 4% vanadium is already considered an average steel, and vanadium monsters with 9% are no longer such a rarity.
In short, knives made from hard steels with a high vanadium content have already come to dominate and need to be sharpened somehow.

In principle, rumors about the impossibility of sharpening knives from such steels are greatly exaggerated. In most cases, they can be sharpened without the use of diamonds, the same S30V and M390 are perfectly fine sharpened with ordinary stones. But at the same time, sharpening of modern knives often turns into a problem, taking a lot of time and leading to severe wear of the bars. In general, if you need to regularly sharpen modern knives, alas, you cannot do without diamonds.
The review was posted on YouTube before the text review was written. And in the discussion under the video, one viewer has already complained that it is not possible to sharpen a vanadis knife with stones based on aluminum oxide - the bars simply slide along the blade without removing the metal. This is an illustration of the above.

ORDER
Everything is simple here. I ordered in an online store, received a confirmation of dispatch and a track number by mail, watched the travel of the parcel in Russia, received it in a couple of weeks. With shipment to Kazakhstan it cost 1326 rubles (even before the devaluation. Eh ...). In general, everything is fine and usual.

THEORETICAL ASPECTS
There are a lot of controversies and myths surrounding diamond bars.
There are two extremes:
1.Diamonds are the best abrasive of all existing, everything else loses to them in all respects, except maybe the price, so you can buy diamond stones, and you will get the perfect tool for all situations.

2. Diamonds can only be used if you don't mind the knife. Yes, diamonds work very quickly, this cannot be taken away from them, but at the same time they work very roughly, creating a defective metal layer, leaving microdefects that go deep into the blade and lead to chips on the cutting edge. Sharpening with diamonds is very short-lived, there is no work hardening effect, etc. etc.

I do not pretend to be the ultimate truth, I will just express my subjective opinion. In my opinion, as usually happens, the truth is in the middle, and both extreme points of view are not unequivocally correct. Diamonds should not be absolutized or demonized. It is just a tool that is optimal in a certain situation and for a certain application, but not very good in another situation and / or application. It has its advantages and disadvantages that must be taken into account when choosing a sharpening tool.

First of all, it is wrong to talk about “diamonds in general”. Diamond powder caricatured in a lap, diamond powder in the form of a free grain on a lap, diamond paste on paper, a diamond bar with an electroplated bond, a diamond bar with an organic bond - these are all diamonds, but they work very, very differently.

Speaking specifically about diamond bars, they are different. In practice, the most common are two options: solid electroplated bonded bars and soft organic bonded bars. Venev diamonds are representatives of the second category.


Electroplated bars are a metal plate on which diamond crystals are fixed (usually with a nickel bond). Diamonds form a layer simply spread over the surface of the bar. This type of diamond is produced by many manufacturers - both Chinese, Edge Pro, and the Poltava plant. This technology is well illustrated by the diagram from the DMT website:


Diamond crystals are firmly fixed in the bond and protrude strongly above its surface.

Venev bars are made in a fundamentally different way. Here, diamond crystals are evenly distributed in the bond and form a layer with a thickness (on the bar from the survey) 3mm. Basically, this is the same as traditional sharpening stones - an abrasive powder distributed in a binder, only here diamond powder is used instead of silicon carbide or aluminum oxide powder.

How does this difference affect the properties of the bars? It has a very strong effect, so much so that it is not worth giving any generalized assessment of "diamond bars in general" to these bars.

Electroplated bars remove metal from the treated surface very quickly and very effectively. This is the merit of the rigid bond and strongly protruding diamonds, which act as cutters that cut deeply into the steel. In most cases, such a bar provides the fastest sharpening in comparison with other abrasives (although, due to certain features, it can sometimes lose in speed). In any case, it is to this type of stones that the assessment of diamond stones as the fastest and most effective abrasive belongs to the full.
The downside is a couple of features.
First, it is clear that since diamond "cutters" cut metal very effectively and deeply, the marks they leave are very rough. Conversations about the very rough work of diamond bars refer, again, to them.
Secondly, if such a bar is curved, then it can be straightened only by bending the plate on which the diamonds are applied, and this will not always be possible, to put it mildly.
Thirdly, in the process of exploitation, diamonds are gradually worked out, torn out of the bundle, and the bar literally becomes bald. As a result, the bar gradually loses its original efficiency and speed.
Fourthly, diamonds are often very unevenly protruding above the bond surface, either as a result of insufficiently high quality workmanship immediately on a new bar, or as a result of uneven baldness. Individual diamonds sticking out will leave deeper risks, greater pressure and risk of flaws.

Bars on an organic bond are very similar in their properties to ordinary sharpening stones. Diamond crystals do not protrude much above the surface; they are embedded in a soft bond. Because of this, such a bar, by definition, cannot work as quickly and efficiently as an electroplated bar.
The downside of this is a couple of features:
Firstly, with an equal size of diamonds, a bar with an organic bond works much less roughly than a bar with an electroplated bond. The risks left behind are not that deep. Talk of ugly rough diamonds plowing the cutting edge mercilessly is largely outside the scope of this type of stone.
Secondly, such a block can be easily leveled.
Thirdly, it retains its properties during operation. When is triggered upper layer diamonds, diamonds below it emerge from under it, and so on until all 3 millimeters of the diamond layer are worked out. According to user reviews, with intensive (but correct) use, Venev diamonds last 5 years or more without problems.
Fourth, there is no problem with individual height-grinding diamonds. But another problem appears - diamonds can be unevenly distributed over the volume: in one place it is dense, in another empty.

If you look at the results of the comparison, you might get the impression that Venev diamonds are better than bars on an electroplated bond, because they have much more advantages. But this is not the case. I'm not trying to conclude that some are superior to others. They are simply DIFFERENT, each type has its own pros and cons that need to be taken into account.
Electroplated diamond bars are indispensable when you need to remove a large amount of metal (remove damage, form leads, change the angle of the RK, etc.). And when peeling is performed, all their disadvantages fade into the background, paying off with performance. But if you need to ensure accurate metal removal, then they are rough. So both types of bars get along well in one set, are used at different stages of sharpening, and, if used wisely, do not lead to negative consequences for a knife.

Returning to the extreme points of view mentioned above. Are diamond stones the ideal sharpening tool for all types of knives and steels? No, they are not. For some knives and steels, they do not work well.
Is everything so bad that it is better not to sharpen knives with diamonds? No, with judicious use, the risk of negative effects can be eliminated or minimized.

INSPECTION
A bar arrived in a plain envelope

Inside there was a sales receipt and a bar in a leatherette case, traditional for the Venev factory.


The case, in principle, is nothing special. Velcro fastener is completely normal. The material of the cover itself is unlikely to impress with some amazing wear resistance. But the very presence of the cover is still a plus, since the bar is protected from any accidental blows.




Let's move on to the bar itself.
The first thing that catches your eye is the reverse side of the form. She looks just gorgeous. Well, really. The surface is as if covered with diamonds and shimmers and gleams when you tilt the bar. The lettering makes it easy to read and looks good in terms of aesthetics.




The original diamond bar Edge Pro looks very pale against the Venevian background.


The external design does not affect the functionality, but still creates a pleasant impression of the product. A little discord with this splendor of the facets of the blank, which have traces of rough processing. The plant would have to remove these traces, since they paid attention to the presentation of the bar.

Well, okay, the bar was not purchased in order to admire it. We inspect the work surface.




There is some kind of unevenness in coloring - somewhere lighter, somewhere darker. What is the reason, I do not know (after the first sharpening, the color became uniform).

If you look with the naked eye, shaking the bar, then the diamonds shining on the surface are clearly visible. I turned it this way and that, it seemed that the distribution of diamonds was quite uniform, I did not notice the difference between the different areas.

Looked under a microscope. It also seems that the bond is quite homogeneous, and the diamonds are evenly distributed.








I measure the bar. It turned out 150.6X25X3.1. There are deviations from the declared dimensions, but a thicker working layer is a plus, not a minus.
One of the most intriguing questions: "What about flatness?" They often complained about the traditional Venevsky bars for manual sharpening that they were crooked. V recent times they began to write that the quality had improved, but there were no reviews about the sharpener bars yet. So…


There is a slight saddle shape, but within the acceptable limits. I didn't even bother to align. The Edge Pro had a similar saddle shape.

Summing up, we can say that the workmanship is good, no obvious flaws were found.
EXPERIENCES OF WORK
Before talking about what results a stone gives when sharpening, I want to note one very pleasing feature of diamond stones. They deliver a minimum of hassle in terms of the sharpening procedure. Unlike water stones, soaking is not required, and so much dirt does not form during the sharpening process. Sharpening is easier and cleaner, less space is required.

The bar is easily cleaned of sludge, dries quickly after rinsing.

Now about the results.
For the sake of experiment, I tried a bar on different knives and steels - from a "pan" soft stainless steel type 40X13 and worse to a quick cut and powder with all sorts of intermediate options between them - such as 8Cr13MOV, 440C, etc.

If you just make some general conclusion, then the bar works well, quickly and copes with all the steels that have been tried. We can say that it is quite universal and, in general, can be a single type (but different grain sizes will be needed) of a bar for different knives.

But there are also nuances.

The bar cuts soft kitchen stainless steel like plasticine. Sharpening happens very quickly, literally a few movements are required. The cutting edge under the microscope looks pretty decent, the risks fall evenly

All this is great, but I consider the use of Venev diamonds for such steels unjustified. Firstly, ordinary stones, including cheap Chinese ones, can easily cope with such steels. Secondly (and this is the main thing), such inferior steels wear out the bar more than hard ones. It seems to be a paradox, but in fact this is understandable: on hard steel, the diamond works like a cutter, cutting and scratching hard carbides, and in such inferior steel it sticks like in plasticine, and as a result, diamonds are simply torn out of the bond, which leads to rapid wear bar.
In general, it is pleasant to work on such steels with this bar, but too wasteful.

Steel-"simple", they are the same average, such as 440C, AUS8, 8Cr13MOV, the bar sharpens easily and very quickly. On this group of steels, especially with low hardness and high toughness, there is still a risk of diamond tearing out of the bond, but not the same as on the previous group. The use of a Venev bar for such knives is, perhaps, generally justified, although it does not provide any special advantages in comparison with ordinary abrasive stones. Lack of soaking and dirt - yes, it is more convenient to work. But in terms of speed, ordinary stones can compete with Venev's. At the same time, diamonds work, whatever one may say, coarser than ordinary stones. It should be understood that the softness and delicacy of Venev diamonds is quite relative. They work delicately against the background of electroplated bars, but the properties of diamonds as crystals have not gone anywhere. So I still prefer to sharpen thin knives at a small angle with other abrasives.

And, finally, the most interesting group steels for which, in fact, the bar was purchased - hard high-alloy powders and tooling. It is on them that the Venev bar fully reveals its merits.
If I say that the bar is eating these steels like crazy, it would be a gross exaggeration. This can be said only about galvanized diamond bars. The Venevsky block rather simply reliably removes the metal, allowing you to sharpen these knives in the same way as you usually sharpen knives from mid-range steels, and not curse because you crawl and crawl with a stone on a knife, and the result is not visible.

With the naked eye, of course, the risks are clearly distinguished:


In general, sharpening of hard alloy steel knives is the main niche for such bars, in my opinion. I do not want to say that the Venev diamonds have no alternative in this regard. Not at all. It is quite possible to pick up bars that, in a given situation, will cope with sharpening no worse or even better than Venev ones.
The main advantage of Venevski is that in them are simultaneously combined versatility, speed of work, softness of work, durability, convenience of work. The alternative options are more highly specialized, they surpass the Venev ones in some of the parameters, but lose in others (galvanic ones are faster, but coarser, silicon carbide in a soft bond works more delicately, but it has strong wear and a lot of dirt, etc.), and Venevian ones combine advantages in all these parameters at once.

ABOUT ACUTE AND GRAIN

To get acquainted with the new bars, the option with a grain size of 50/40 was chosen for two reasons:

Firstly, this block is a "workhorse", which bears the main load during sharpening, and if we take a block for a start, then the most popular one is better.

Secondly, it was interesting to check one point of view. Quite often, among sharpeners, the opinion is expressed that 50/40 is the optimal grain size for achieving "working sharpness" and that there is no point in bothering sharpening to a high degree of sharpness - this is a waste of time that has no practical sense. This is expressed specifically in relation to Venev diamonds. Sounds tempting. If you practice this approach, then sharpening is simplified to the limit. The 50/40 bar works quickly and allows not only sharpening, but also repairing minor damage, i.e. in fact, it can become generally the only bar from which sharpening begins, and on which it ends.

The cutting edge obtained as a result of sharpening by 50/40 is naturally quite "toothy", which is clearly visible in the photo under a microscope. How sharp it is is clearly visible in the video. Could this sharpness be considered optimal? Everyone decides for himself. In principle, yes, the knife is quite sharp, it allows you to shave hair from the forearm, etc. But I would not consider such a sharpening optimal for all applications of the knife. This sharpening is good when you need to cut some ropes, tarpaulin, meat and other similar materials - it cuts very aggressively, "with a crunch." But if you need to plan something, when you need increased durability of the RK, I will choose a thinner and more thorough sharpening and finishing.

OUTPUT
I will summarize for those who do not have time to read the entire review.

The workmanship of the bar (size correspondence, flatness, uniform distribution of diamonds in the bundle) is good.
-Impressions of the sharpening results are positive
- It is very convenient to work, since it is not required to soak, there are no problems with cleaning from sludge, there is no such amount of dirt as when using water stones.
-The main advantages are the combination of versatility, productivity, accuracy of work and durability in one bar.
-Although the bar is versatile, in my opinion, it is still better to use it for sharpening knives made of hard alloy steels, which are problematic to sharpen with traditional abrasives.

disadvantages
- no obvious shortcomings were revealed. But, perhaps, a rather high price can be noted, in connection with which the sharpener bar is experiencing internal competition from the hand sharpening bars of the same manufacturer. You have to choose: "economy or convenience?"
-Another factor is not a disadvantage, but rather a feature of Venev diamonds: the speed of work is moderate. It is normal, but it can deceive the expectations of those who have heard enough about the crazy speed of diamond stones.

QUESTIONS WITHOUT ANSWERS

Just in case, I clarify that all the above conclusions were made regarding one particular bar with a grain size of 50/40 with a concentration of 100%. To what extent they can be extended to other options, I do not yet know. This version of the bars is a novelty, and so far there are practically no reviews.

I myself have questions to which it would be interesting to get answers. Perhaps someone will tell you if he knows and / or has already bought it?

1. How consistent is the quality of new bars of different grain sizes? Previously, on small blocks there were problems with uneven distribution of diamonds in the bundle.
2. Has anyone compared bars with the same grain size but different diamond content (25/50/100%)?

3. What is the difference between the new versions of the bars and the old ones? I decided to purchase a range of coarse to fine bars and it turned out that there is a variety of bars on the market with a slightly different designation (letter designation Coarse, Medium, etc. and a different grit range - 60/40 instead of 50/40). Recently, even in their descriptions it was indicated that they have some kind of new improved bundle, but now I do not see this phrase. So how are these options really different and what to prefer?