Fixture for bent square pipe. Is it possible to bend a profile pipe without a pipe bender? Hot bending method

Often the question arises of how to bend shaped tube without a pipe bender? It is known that the execution of various construction or renovation works on a suburban area assumes the widespread use of profiled pipes.

The use of this type of rental has a number of advantages:

It has great strength at a relatively low weight.
The profile pipe can be used for the installation of any structures from a greenhouse to various sheds, gazebos or verandas.
Possibility of processing by welding or different kinds hand tool allows you to do most of the work with your own hands.
The construction, assembled from a square profile, will look much more attractive than its counterpart from a traditional round pipe.

If there is a desire to make an arched structure to decorate a gazebo or install a greenhouse, you will have to bend it manually or resort to the help of specialists.

Main features of bending technology

It is necessary to clearly understand the processes that occur in the metal during its controlled deformation. The main goal in this case is to obtain a uniformly curved shape without violating the integrity of the rolling profile. To correctly bend a pipe of any cross-sectional shape, two methods are used:

flexion under the influence of external force;
combination of pressure and local heating in the bend section.

In both cases, the following processes occur simultaneously - the material of the outer layer of the arc will stretch, and the inner layer will shrink. As a result of bending, a significant excess of the load can lead to cracks and destruction of the outer wall of the pipe. The inner surface can lose its smoothness, while well-visible metal folds are formed. Violation of the process technology can also cause distortion of the pipe walls or dislocate their alignment. Such a phenomenon will have an extremely negative effect on the aesthetics of the resulting arch and will cause its forced rejection.

There are other parameters to consider as well. The radius of the desired curvature, the wall thickness of the workpiece, its material and cross-sectional dimensions will be of great importance.

The industry produces shaped pipes that have a square, rectangular, oval, flat-oval or round cross-section. Use when executing construction works products of square and rectangular shape have their advantages. Such pipes are much more convenient when performing installation works... They simplify the marking, docking and fitting of structural elements with each other. It is much easier to attach various coatings to a flat surface of such a profile or combine them with other materials.

Methods of cold bending of pipes: a - with running-in; b - winding; c - by dragging; d - rolling; d - on two supports; e - stretching; g-with internal hydrostatic pressure; and - through a die having a curved axis; k - by copiers.

Pay particular attention to the section height. This indicator determines the plastic parameters of a particular grade of rolling material. Based on its value, the maximum possible bending is calculated. Let us denote the height by the letter h. Then, with a size of up to 20 mm, it is possible to bend the pipe without destruction in a section of 2.5 × h and more. In cases where h> 20 mm, the formula is: 3.5 × h or more. Violation of this rule will lead to the formation of cracks or general warping of the metal.

The thickness of the profile walls must be taken into account. If it does not exceed 2 mm, it is impractical to bend the material. In such cases, welding has to be used. Thicker walls lend themselves to bending, but the increase in thickness makes it much more difficult.

The material of the rolled profile can also have an effect on the process. Low-alloy and carbon steel pipes have significant elasticity. Such material, after removing the external load, tends to restore its previous shape. This will require re-machining until the required arch radius is maintained. Copper pipes do not have this disadvantage. Due to the high ductility of the material, they easily change shape and retain their changed state after removing the load.

Profile bending methods and sequence of their execution

The choice of bending method depends primarily on the size of the cross-section and the available tools and equipment. Usually small materials are cold bent. Such pipes have sufficient ductility and amenable to controlled deformation with low external forces. For profile big size heating is usually necessary. Temperature action significantly increases ductility and reduces the required amount of applied pressure.

For pipes with circular cross-section, heat treatment is used with a diameter of 100 mm and more. For square and rectangular products, the calculation takes into account the cut height. If the profile height is up to 10 mm, heating is not applied. With a height of 10 to 40 mm, the processing method is selected based on the experience and capabilities of the performer. When the size exceeds 40 mm, local heating is necessary.

The presence of a pipe bender allows the manufacture of arched structures without additional heat treatment. In cases where machining is not possible, test bending should be performed. The profile is clamped in a vice, a pipe is put on its protruding end larger diameter, which is used as a lever for the applied force. No heating is required.

Bending with local heating

The technology of such processing involves filling the pipe with sand. Its presence in the inner cavity of the product guarantees the quality of workmanship and the uniformity of the arch.

Initially, you need to prepare two wooden plugs. They must have a pyramidal shape for a tight seal. The length of the plugs should be 10 times the profile width. After manufacturing, the plugs are tried on to the pipe holes, while checking the tightness. Further, on one of the plugs, sawed longitudinal grooves on the side surfaces. Their presence is necessary for the discharge of overheated air from the pipe during heat treatment. The place of the future bending of the product is determined and the preheating of the metal is performed.

After that, they begin to prepare the sand. It is best to use dry and clean medium grit material. It is successively sieved through sieves with meshes of 2, and then 0.7 mm. This removes large impurities that can cause a bumpy surface and dust that can sinter inside the pipe. The filler is heated to a temperature of 150 ° C.

We hammer a cork into the pipe, which does not have longitudinal cuts, and fill the prepared sand through the funnel. When backfilling, it is necessary to tap with a wooden mallet on the walls of the profile to ensure the compaction of the material. After the final filling, the second plug is installed and tightly clogged.

The fully prepared pipe is positioned in a vise or pipe clamp next to the template. If there is a pipe seam, it must be positioned on the side of the arch. The area marked with chalk is heated with a blowtorch to red and bends in one smooth, unsharp movement. The resulting arch is compared with a template, after which the plugs are removed, and the filler is poured out. It must be remembered that repeated heating is highly undesirable, as it significantly reduces the strength of the material.

Bending without heating

The question of how to bend profile pipes without a pipe bender can be solved without temperature exposure. The use of the filler depends on the dimensions of the section. If its height does not exceed 10 mm, no sand is needed. For large sizes, the use of bulk material is highly desirable. Alternatively, it is possible to use a steel spring made of wire with a diameter of at least 2 mm. It is preliminarily placed in the place of the future bend to give it a smooth uniform contour. The technology of the process itself completely coincides with the hot method, with the exception of heating the metal.

The use of manual pipe benders or specialized machine tools during the bending process of profiled metal significantly speeds up and facilitates the process.

The work of professionals guarantees the high accuracy of the contour and its quality. But if the possibility of attracting them is not available, it must be remembered that this work can be done independently, while significantly reducing your costs.

When performing construction or repair work on the house of various levels, the problem of bending shaped pipes regularly arises. This is usually necessary when building greenhouses on summer cottage, installing the gate, various designs for winter garden, at home, as well as in the arrangement of terraces. The profile pipes themselves have a high strength index, and in order to give them the necessary shape, you need to make some effort.

In this article, we will describe how it is faster and more convenient to bend a profile pipe on your own at home using special pipe bender equipment or using a conventional angle grinder (grinder) and a welding machine. We will tell you all the secrets of correct pipe bending and describe a number of problems that can be encountered in this process. We will also tell you why you cannot bend square pipes with the help of special equipment.

Pipe bending technologies: how to bend a pipe correctly?

How to bend a steel or copper pipe correctly? Can this be done without losing the properties of the metal? There are several different technologies, one of the most convenient and fastest is the use of a special machine designed for bending shaped pipes. In professional language, it is called a profile bender, but the cost of such a device is quite high, so you need to have many good reasons to purchase it.

In the event that you plan to bend pipes a small number of times, then in specialized stores you can purchase special hand-operated pipe benders, with which you can bend pipes of various shapes, but this is most optimal for round pipes, because all the elements have exactly a semicircular shape. The cost of such equipment is relatively low, usually it is about 3-3.5 thousand rubles.

For bending pipes at home, you can use more simple ways based on the use of a welding machine and an angle grinder. This technology will be described a little later.

Often, copper, steel and polymer pipes with a small cross-sectional width can be bent with the help of improvised means and physical efforts, but in this case it is difficult to control the bending radius. This method is best suited for copper pipes, since ordering it in a workshop is not cheap at all.

Features of bending using a pipe bender

The priority of using a special pipe bender in the household should be foreseen even during the purchase of products, if you nevertheless decided to take such a step. Most often special equipment purchased to work with big amount shaped pipes, for example, in the construction of houses and the construction of fences. In this case, you need to immediately take into account what kind of pipes this device can bend, because often inexpensive models can only work with circular shaped pipes.

Bending a round or square pipe with a pipe bender is quite simple on your own. In this process, only the wall thickness, the diameter of the pipe section, the radius of the future bend and the material of manufacture need to be taken into account. During operation, the bending is carried out in accordance with the technical tolerances of the pipe wall thickness and the size of the section, while during operation it is necessary to ensure that no breaks appear on the inside of the product, as well as flattening of the cross-section of the profile.

When working with square pipes, when it is necessary to bend with a small radius, the force must be applied closer to the ends of the product, because in the central part the pipe will be very difficult to bend.

How to bend a profile pipe?

In order to bend the pipe not independently, but with the use of special equipment, it is necessary to use devices whose operation is based on cold stretching technology. In this case, stretching the profile leads to the fact that the neutral axis of the entire structure is displaced towards the required bend, therefore the probability of obtaining a corrugated part is practically zero. The pipe remains smooth throughout its entire length, fractures and other defects simply cannot appear on its surface, strength and other important characteristics remain the same.

The pipe bender wraps around the product very tightly, bends and stretches at the same time with absolutely verified movement of the bending template.

With the help of special equipment, the profile product can be qualitatively bent in the desired direction and at the required angle, preserving all the characteristics of the pipe and preventing the loss of stability by the walls. The secret of this technology is extremely simple, the bend is made in the presence of hydrostatic pressure inside. Special plugs are installed at the ends of the profile pipe, and liquid is fed into the system. Then the bending template is brought to the center of the product, and the required shape is achieved using the applied force.

How to bend a profile pipe without a pipe bender

You can bend the pipe at home quickly and easily enough, without resorting to using a pipe bender. This does not require the use of expensive and bulky tools and machines, but the bending quality is quite good, and the profile remains attractive. appearance without losing their properties. You can do this yourself using a welding machine and a grinder. Work is carried out according to the following instructions:

Initially, you need to correctly calculate the radius of curvature, optimally prepare a preliminary scheme, which will greatly simplify the process of work, make it high-quality and fast.
On the surface of the profile product, along the length of the section that needs to be bent, it is necessary to perform uniform cross cuts on three sides. This is done independently using an angle grinder.
Next, you need to make some physical effort and bend the pipe in the required direction. Many professionals recommend that it be carefully fixed so that the bend is neat and the pipe is located in the same plane. This can be done, for example, in a vice.
Using the prepared welding equipment, all cuts are welded in accordance with safety regulations.
Now the welding spots need to be sanded and carefully processed.

This technology can achieve the most accurate results without the use of complex and specialized equipment, which is a pipe bender.

Pipe bending using internal means

Profile pipes of various cross-sections can be bent using means that have an internal effect on the structure. To do this, you first need to make a spring with a square section of steel wire, which has a thickness of one to four millimeters. The value must be selected in accordance with the profile thickness.

The prepared spring must be carefully wound, while the size of each section of the spring should be 1.5-2 millimeters less than the inner diameter of the section of the profile product, in this case the spring should be free inside the product that needs to be bent.

Now, with the help of a blowtorch, the section intended for bending is heated. This should be done very carefully, using pincers and protective gloves. After heating on a specially installed blank with a radius equal to the profile radius, the pipe is bent.

If the pipe needs to be bent in winter period or in a cold room, a slightly different technology is used. For this, the pipe is initially filled with water, and plugs are installed at its ends. After the profile is set in the cold, until the water inside the product completely turns into ice. Now the pipe can be bent independently on a blank without any serious physical effort.

Duralumin and brass pipes can be bent according to the same principle, if this is possible, then the profile product will retain its properties and integrity.

How to bend a profile pipe at home

Any of the above methods can be used to create a pipe bend. All technologies differ in the required equipment, process time and necessary physical efforts. Of course, it is best to carry out this process using special equipment, but if this is not possible, you can use the classical methods of bending shaped pipes. A manual pipe bender can greatly simplify and speed up this process; you can find it in any hardware store at a fairly affordable price. However, if you already have a welding machine and an angle grinder, you can use them. The main thing - do not forget about safety measures, always wear a protective mask and special gloves, only then the process of bending pipes will not be difficult and will not lead to possible problems.

The greenhouse frame with a square or rectangular cross-section attracts with its reliability and durability. A very strong metal structure allows maximum light to pass through, because its racks, supports, ties are much thinner than those of wooden rivals. The metal is inferior in manufacturability. Without knowing the nuances, it is difficult to make an arched arc or frame for a door from a straight blank. Because of these complications with a metal base, it is in vain that they prefer to buy "green houses". However, if you really understand how to bend a profile pipe for a greenhouse, you can build an inexpensive arched structure with your own hands at low cost.

The essence and problems of bending profile pipe

The bending of metal products, regardless of the cross-sectional shape, consists in giving them a partial or full smoothly curved configuration. One of the common locksmithing procedures is performed either under pressure alone or under pressure in combination with heating the bent section. At this time, compressive forces with inside workpiece and tensile forces along the outer wall. Complications are that:

the material in the process of changing the shape may lose the coaxiality of the segments, i.e. parts of the bent workpiece will not be located in a single plane;
the stretched outer wall at the bending section may not withstand the impact and it is corny to burst;
the compressible inner wall may, instead of being uniformly contracted, fold into corrugation-like folds.

Without knowledge of the intricacies of profile bending, there is a risk of simply crushing the product, spoiling the workpiece. But recklessness is not our way! Moreover, if it is accompanied by material losses. For the glory of rational economy, we will take into account all the vagaries of the profile and characteristics of the "iron" material. Let's not forget about the dimensions of the section, the thickness of the walls of the profile pipe, the required bending radius and the elasticity of the steel alloy. Focusing on the specified parameters, we will choose the correct technological path - it is also a bending method.

Why do you need to know profile characteristics?

Profile pipe-rolling differs from the standard round version in the shape of the section, which can be square, oval, rectangular or flat-oval. According to the regulations of GOST R under the number 54157-2010, the round product is also included in the list of profile products. However, in greenhouse construction, products with a square and rectangular cross-section are most often used, for example, profile pipes 40x20 mm, because it is easier to attach a coating to their even flat walls.

For various national economic needs, products are produced in a wide range of sizes. It differs in configuration and cross-sectional area and, naturally, in wall thickness. The set of sizes determines the plastic possibilities. In professional language, they are called the minimum permissible radius of curvature. So, before you know how to make a workpiece for the frame, you need to find out what the smallest radius of flat round deformation the workpiece can "survive" without damage.

To determine the minimum allowable bend radius of a square or rectangular profile, we need the height h, because:

products with a profile height of up to 20 mm will be bent without passing into the category of unsuitable rejects, if the bending is performed on a section with a length of 2.5 × h or more;
rolled pipes with a profile height of over 20 mm will withstand deformation without loss in a section with a length of 3.5 × h and more.

The indicated limits are necessary for those who conceived to make racks, shelves and frames for vents or doors. The wall thickness also makes adjustments to the area of limitations. Wide pipes with thin walls up to 2 mm thick are generally not recommended to bend. Better to use welding.

Home craftsmen, who decide to make arcs for, need to take into account that products used in everyday life made of ordinary carbon or low-alloy steel alloys tend to "spring" slightly after applying efforts to them. They seem to be trying to return to their previous state. Therefore, after a novice locksmith with his own hands completes the bending of all arcs, he will have to repeat the processing and re-fit the arches according to the template. It is desirable to initially take into account the value of the plastic moment of resistance Wp. It is usually indicated in the documents of the building material sold. The smaller the moment, the less fiddling with fitting.

Bending methods and their features

Profile pipe-rolling is bent both in cold and hot condition. Heating with a gas burner will noticeably increase the ductility. However, a material of small cross-section bends excellently without unnecessary temperature effects, because thin pipes are quite plastic and more easily amenable to the force applied to them.

There are no precise guidelines for using heat for bending. The standards indicate only the dimensions of the round bars, according to which the flame must be exposed to the treated area at Ø 100 mm or more. With square and rectangular shapes, everything happens a little differently. Based on the experience of craftsmen:

at a profile height of up to 10 mm, the workpieces are uniquely cold-bent;
with a profile height of 40 mm or more, pipes are bent with heating.

How simpler and easier it is to bend a profile with a height in the range from 10 to 40 mm at home, the performer will have to decide on his own. If there is a profile bending in the arsenal of the master, with its help you can create an arched rounding without heating. There is no apparatus, it is better to test your strength in advance. To do this, you need to clamp one end of the material in a vice. On the other end, put on a pipe larger than the height of the profile, and pull on the "shoulder" enlarged in this way. If it works, heat hardware it makes no sense.

Option # 1 - bending with heating

We will deform the non-yielding material by the hot method, having previously filled it with sand. So the quality of processing will increase, and the uniformity of the fold will be ensured. We'll stock up on tarpaulin mittens for hot work and start:

from scraps of timber or logs we will make two pyramidal plugs, the length of which should be 10 times the width of the base. The base area of each homemade plug should be almost 2 times larger than the square or rectangular hole that it has to plug;
let's try how the plugs will "sit", then on one of them we will select the longitudinal grooves on the four sides. They are needed to release the gas that accumulates when the filler is heated;
pre-anneal the workpiece in the area of the future fold;
let's prepare the filler. As it we will take clean building sand of medium grain size. In the absence of bulk building material, we will use the sand from the children's sandbox. First we sift it through a sieve with meshes of 2 or 2.5 mm to remove gravel and gobies from the packing. Large inclusions on the pipe surface can form unnecessary relief. Then we “pass” the sifted mass again, but this time through a fine sieve with 0.7mm meshes, so that dusty particles do not sinter when heated. All screenings, as well as the filler at the end of the actions, will be returned to the sandbox;
calcine the filler at a temperature of 150 ° C;
we will hammer in one end with a wooden stopper, on which there are no channels for exhausting gases. Install a funnel at the other end. Depending on the size, we will install the workpiece at an angle or perpendicular to the ground. We will pour the filler through the funnel in portions. Periodically tap on the walls of the product from bottom to top with a wooden or rubber mallet so that the sand is compacted. A dull sound will be a signal of sufficient compaction;
close the filled blank with a second plug;
mark the heating section on the workpiece with chalk;
fix the workpiece either in a vise with a template, or in a clamp. Install the material with the welded seam so that the welded joint is on the side. It is undesirable to stretch or squeeze along the seam;
heat the marked area red-hot, and carefully give the workpiece the required shape. We bend in one step with a forward, unsharp movement in a strictly horizontal or vertical plane;
after cooling down, compare the result with the template. If everything is in order, knock out or burn out the corks and pour out the sand.

The described method is good for the formation of single corner bends, because it is strongly not recommended to heat pipes several times. Metal loses strength from repeated thermal shock. However, when creating a rounded arch, repeated heating is inevitable. After all, it is unrealistic to do the work in one go, and chilled to a light cherry hue, i.e. up to 800 ° C, the workpiece can simply burst.

Option # 2 - cold method

Cold plastic deformation of profiled steel is carried out with or without filler. Material with a profile height of up to 10 mm does not require filling. A thicker pipe is best filled with sand or rosin. An alternative to the sand filler will be a tightly wound spring, the dimensions of which will allow it to be tightly installed in the cavity at the processing site. The spring washer will prevent a sharp change in the profile section at the bend points.

You can bend "cold" at home:

manually using the simplest devices such as bending plates, vice and mandrel;
with the use of a mobile profile bender - an improved analogue of a manual pipe bender. The profile bending device differs from the device for bending round pipes only by the shape of the working roller recess;
by rolling on a homemade or factory roll forming machine, which can be made by hand or purchased ready-made.

It is more reasonable and profitable to rent technical means of mechanization of bending if they are needed for a one-time construction of a greenhouse. If, in the future, the construction of green houses for relatives and neighbors or the construction of a beautiful metal fence, for example, there is a reason to acquire your own bending machine.

Bending devices and machines

In the family of devices and units for bending there are representatives of varying degrees of technical complexity. To begin with, consider the means for those who are puzzled by the question of how and by what means it is possible to bend a profile pipe without the use of special equipment. Then we move on to homemade rolling plants.

Variants of the simplest devices

The use of elementary "helpers" for cold deformation is regulated by the size of the material:

thin rolled pipes with a profile height of up to 10 mm are bent using a horizontal plate with holes. Metal pins are rigidly installed in the holes, playing the role of stops. Bend the product by placing it between the stops installed in the holes according to the bending radius. They start from the middle of the workpiece and gradually move towards the edges. The disadvantages of the method are the application of considerable muscular efforts and a rather low deformation accuracy;
pipes with a profile height of up to 25 mm are bent using roller devices operating on the principle of the Volnov machine. The metal workpiece is firmly fixed in a vice, and a physical force is applied to the workpiece through a roller. The bending is performed more efficiently and more uniformly than in the previous case. But from the performer, by analogy, remarkable efforts will be required.

To form a bend with a large radius of curvature, such as arcs for an arched frame, fixed rounded templates with clamps are used to fix the workpiece. These devices belong to the category of plane-parallel plates. The workpiece is forced into a groove, the dimensions of which are equal to the dimensions of the pipe. The pipe, which is manually bent with a mandrel, takes the shape of a predetermined contour.

Upgraded bending plate

If a home locksmith is not deprived of physical strength, he will come in handy for his own needs simplest tool for a rather laborious deformation of the profile pipe. It can be made in the form of a panel attached with clamps to the work table or workbench. In the case shown in the photo, the bending plate is welded to a metal pedestal, but it is screwed with four bolts to concrete floor workshop. To remove the device at the end of the work, it will be enough to unscrew the bolts. After dismantling, no fastening pins remain or rise above the floor surface, which means that nothing will interfere with movement and create traumatic threats.

The principle of manufacturing the working plane is extremely simple:

The bending plate is a panel cut from thick sheet iron.
The panel is welded to a profile pipe, installed according to telescopic rules in a pedestal post.
In the working plane, two holes were drilled for the bolts, which are stops.
The bending radius is adjusted by installing a suitable size nozzle on one of the bolts.
In order to maintain the alignment of the segments adjacent to the bend, a metal plate is installed above the workpiece, fixed with bolts.

The pedestal is multifunctional. Its owner has the opportunity to use it as a miniature workbench for performing an impressive number of plumbing operations.

Mandrel for bending the profile pipe

The method is suitable for products with a wall height of up to 25mm. The master will need a large workbench and a significant amount of free space around working area... One edge of the workbench is perforated with frequently spaced holes for fixing the mandrel and for choosing the optimal position of the part holding the pipe. The template for the impending plastic deformation is cut from thick plywood. True, the plywood mandrel is only suitable for one-time bending procedures. If there is a lot of bending work to be done, it is better to weld the mandrels from a steel corner.

Using the manual profiler

Significant volumes of deformation work require mechanization. Mass production of bent parts will take too much health away from the performer. To facilitate bending, it is advisable to make a machine according to the drawing. They are mainly used for working with large-sized workpieces. The main working bodies of the hand-held unit are three rolls, two of which are fixed motionless. Changing the position of the third movable roll determines the bending angle.

If the above methods are not acceptable, then the future owner of the greenhouse has two options - renting a manual installation or ordering the manufacture of rounded parts. The process of deformation of the workpiece was demonstrated by a video: how it is easier to bend a profile pipe - by repeated rolling or physical impact, it is up to the performer to decide.

When working manually, it is important to follow the rules for bending shaped pipes and not make sudden movements. It is necessary to monitor the uniformity of deformation on the outside and inside of the rolled product. However, you should not be too upset about small folds on the inner surface of the fold: they can be corrected with hammer blows. Before starting work, it is necessary to make templates from wire, chipboard or gypsum board for verification and obtaining a result corresponding to the project.

In the presence and independent arrangement of a private house or summer cottage, almost every developer is once faced with the need to perform pipe bending. Many people think about how to bend a profile pipe at home when erecting greenhouses, gazebos and other structures of this type on the site.

And this is not surprising when you consider that shaped pipes look much more advantageous in comparison with products of ordinary circular cross-section.

However, if a pipe with a circular cross-section can be bent with an ordinary pipe bender, then the profile one cannot be bent with it, since with ordinary hydraulic pipe benders the rollers and shoes have a rounded bend, which when trying to bend the profile pipe will lead to cracks, kinks on it, or the pipe will simply flatten.

Profile pipe bending methods

How to bend the profile pipe yourself in this case, avoiding damage? For this purpose, several methods are used, one of which is bending by means of special machines that are designed just for shaped pipes.

This type of machine is called profile bending machine. Nevertheless, the cost of such machines is quite decent, and why would an ordinary homeowner need professional equipment?

If you do not need to bend the professional pipe all the time, but from time to time, you can find hand benders on sale that are suitable for both profile and "round" pipes, which, moreover, are not so expensive - up to about $ 100. It should be borne in mind that in the process a manual pipe bender will require the application of significant physical effort.

With a single need to bend a profile pipe, it is impractical to purchase a tool and it is better to contact a workshop or a workshop of the corresponding profile, which will provide the necessary service for reasonable money, or sell a finished bent product.

This option will save both time and money, while the result of resolving the issue will be exactly what is needed - bending the profile pipe to the required radius.

Another method that is often practiced in such cases is to bend the profile pipe with your own hands using, so to speak, folk remedies... However, in this way it is possible to bend pipes of small sections - steel, copper, polymer.

Bending of shaped pipes using pipe benders

Features of bending

How to bend a profile pipe yourself? This should be done based on the size of its section, wall thickness, material from which it is made, and also the bending radius.

In addition, consideration should be given to the manufacturing conditions, the required bending accuracy and the quality of the resulting product.

The bending of shaped pipes is carried out within the technical tolerances for wall thickness and section size. In this case, the task is to avoid such undesirable phenomena as fractures on the inner part of the bent pipe and flattening of its cross-section.

Before bending a square pipe along a small radius, you need to remember that bending should be made closer to the ends, since in the middle part of the pipe it will be more difficult to succumb to this.

Bending a pipe

To bend, you will need a pipe bender specially designed for cold bending with stretching. The resulting tension with such a tool will shift the neutral axis of the pipe in the direction of the bend, which reduces the likelihood of a corrugated surface at the bend.

While in the machine, the pipe is wrapped around the edges and stretched, and at the same time it bends when the bending template moves.

How to bend a stainless steel pipe without losing the quality of the pipe? To prevent the loss of durability of the pipe walls at the bend, bending is performed under internal hydrostatic pressure: plugs are put on the ends of the pipe and a liquid is fed into it, after which a bending template is brought to the middle of the pipe, with the help of which bending is performed, giving the pipe the desired shape.

Bending pipes at home

You can bend a profile pipe with your own hands without the help of special machines and tools. Moreover, in most cases, you can achieve a bend of really good quality.

Bending using a grinder and welding

Before bending the profile pipe, you will need to arm yourself with a grinder and a conventional welding machine.

Bending is performed in the following sequence:

Calculate the radius of curvature of the pipe.
Along the length of the bent section, cross cuts of three sides are evenly performed.
After that, the pipe is easily bent.
The sawn places are welded.
The welding site is processed and polished.

In this way, an impressive external result can be achieved with the desired bending radius of the pipe.

Bending using internal countermeasures

One of these means can be a specially made spring. Before bending the profile pipe, a square spring is wound from steel wire 1-4 mm thick (depending on the thickness of the bent pipe).

The size of each side of the spring segment should be 1.5-2 mm less than the internal values of the pipe section so that the spring can penetrate into the pipe without any effort.

After installing the pipe in the place of the intended bend, immediately before bending the profile pipe, the bent section is heated with a blowtorch. Next, the pipe is bent on a blank, the radius of which is equal to the required inner radius of the bending pipe.

If it is necessary to bend in winter, a somewhat original method can be applied.

So, how to bend a profile pipe:

A copper pipe is filled with water, having previously closed one of its ends with a stopper.
Expose the pipe to frost until the liquid completely freezes.
The bending of the copper pipe can then be carried out according to the template of the corresponding radius with practically no loss of section and without effort.

Duralumin and brass pipes can be bent in the same way.

How to bend a professional pipe without a pipe bender? Prepare several buckets of dry, clean sand. If it was not possible to get clean sand, ordinary sand lying in the yard will do.

It will need to be sieved and dried properly by calcining it over a fire or using gas burner until the sand ceases to float and smoke. After processing and cooling, the sand is poured into a dry and clean container.

Before bending a square pipe, a wooden wedge is driven into it from one side to a depth of 10-20 cm, and then prepared clean and dry sand is poured into the free hole of the pipe until the pipe is completely filled. Next, a similar wedge is hammered on the other side of the pipe and the bending process begins directly.

The operation, as in the previous cases, is performed using a blank with a diameter corresponding to the required inner bending radius. If the bend is too steep (small radius), the bend can be heated with a burner. The sand tightly packed into the pipe will prevent it from losing its integrity or severely deformed.

At the end of the bending, one of the plugs is burned out at the stake, the sand is removed from the pipe and the second plug is knocked out or burned out of the pipe. It will not take much more time to bend in this way, in comparison with how to bend a profile pipe using a pipe bender.

The methods for bending shaped pipes presented in the article will be effective if all the above conditions are met, however, bending of really high quality in every sense of the word can be achieved only with the help of professionals who will perform work on specially designed equipment. Approach work with knowledge of the matter, only thanks to this it will be possible to achieve the desired result, while spending a minimum of money and effort.

Almost every owner has a situation when it is necessary to change the bend of a metal rod to install a greenhouse or wiring a sewer. Since it is quite easy to bend a profile pipe at home with your own hands, this work does not require the involvement of specialists.

The average homeowner rarely has special equipment available. Therefore, you need to know how to correctly bend aluminum or steel pipe for a greenhouse, a canopy (shed) and other needs without a pipe bender.

Photo - bending pipes without a pipe bender

It is very convenient to produce this work using a welding inverter and a household grinder. To begin with, a drawing is being developed, according to it, the required angle will be drawn and calculated in the future. In the scheme, the rounding is necessarily accurately measured.

Step-by-step instructions from an expert on how to bend pipes using a vice, a grinder and a welding machine:

If you plan to bend the professional pipe in a semicircle, then at the place of the proposed bend, several thin cuts are made with the help of a grinder;
You can do the work yourself only if you first fix the reinforcement in a clamping vise. When the cuts are made and free of chips, you need to carefully start bending the pipe;
After the ring has closed, you need to weld the holes that were formed as a result of bending with a welding machine. Some craftsmen use simple soldering irons if the communication has a small diameter;
In order for the place of the fold to be neat, it will need to be additionally sanded and covered with a protective agent - this will help prevent the appearance of corrosion or premature destruction of the connection.

You can bend the pipe exactly by means of a spring, which is suitable for the size of the profile section:

Communication is fixed in a vice;
A spring of the appropriate diameter is inserted into the hole. This will prevent the profile pipe from breaking or taking an irregular shape when bending;
To facilitate the work, you need to warm up the joint and carefully manually bend the communication to the desired diameter;
Various metal products suitable for inclination, for example, grinders, arches, etc., are very helpful here.

Similarly, you can try to deform communication. with sand... How to properly bend a canopy pipe without the use of a vice and springs:

It is necessary to stop one end of the tube by closing it with a wooden wedge or any other plug;
The closed end of the pipe is fixed in the ground or in a vice (if possible). You can also use any other device that allows you to establish communication;
After that, you need to pour sand into the open end and warm up the blowtorch;
A heated lamp must be held at the place of the future bend, and then carefully bend the pipe into the desired shape. It is necessary to work rather quickly, since the metal after it cools down will be unsuitable for processing.

Video training on how to bend a 20 mm pipe without a pipe bender using sand

After making the bend, it is required to leave the pipe in a fixed position for a while - this will help the material to fix its new shape. If the work is carried out in the winter, then the masters put them out even in the cold.

Arch (canopy) without pipe bender

As you know, for a canopy, for example, in the form of an arch, a curved profile pipe is needed. It is important to make sure that the arcs are equally curved, otherwise the canopy will not work. Now we will look at how to do this without using a machine, a pipe bender and other aids of this kind.

We need:

A support on which we will work, for example, a metal table;
As a beam, you can take a pipe 80 by 60 or 50 by 50 mm with a length of 3 meters. But this method is universal - so what kind of support beam you will end up with is not important;
Profile pipe 20 by 20 or 20 by 40 mm, which we will bend.

Procedure (step by step instructions):

Important note from an expert:
In the length of the racks, the whole secret of bending the professional pipe with an arch for your canopy lies. The lengths of the two posts are formed from the length of the middle post (we have 250 mm - you can take a different length, but not more than 250 mm - otherwise the pipe may break when bent). The coefficients 0.8888 and 0.5556 are valid for any length of the support and B-pillar.

Video instruction on how to bend professional pipes for a canopy (arch) without a pipe bender

Now let's look at how to bend a pipe using a pipe bender

There are two types of pipes:

Profile;
Round section.

Depending on your needs, you need to choose a specific option, but it should be remembered that working with round reinforcement is much easier than with square one. The fact is that when bent, the corners can bend or flatten, moreover, there is a high probability of cracking.

Photo - Greenhouse from shaped pipes

To bend a profile pipe at home, you need to work with a special device - or a profile bending machine. Their feature is the ability to establish communication in the device and fix it in a certain position. Due to the pressure, which is exerted equally on both the outer corners and the inner ones, an even bend is formed without sharp drops and cracks.

Photo - mechanical profile bending machine

Exist two kinds of roll forming equipment:

Manual;
Professional automatic.

The first is a fairly simple device that consists of a work surface (table) and a number of rollers. Due to the movement of the rollers, the pipe moves along the work table and changes its angle, while not distorting the desired semicircle.

Professional devices are more convenient to use, but their cost often exceeds 20,000 rubles. They are used for complex work, most often required for the production of complex decorative metal elements. The advantages of the model include the ideal radius, which will be accurate literally to a tenth. Of course, when using the machine it is more convenient to work, but at home it is practically not needed, since it is intended for processing a large number pipes per shift.

Photo - manual pipe bender

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