How to bend a square pipe yourself

How to bend square pipes?

Most owners of dachas, cottages and private houses have to deal with the issue of how to bend a profile pipe at home without a pipe bender.

The desire to arrange the local area in a presentable and original way leads to the need to create arched structures. These are canopies, gazebos, canopies and greenhouses made of cellular polycarbonate.

Buying factory-made products comes with costs that can be avoided by bending the steel in-house. To do this, there are enough tools and materials available in every workshop.

Bent pipe

What is the problem with profile bending?

Rolled metal with a rectangular cross-section is easy to work with, and the workpieces can be joined at different angles. Difficulties arise when there is a need to give the design parts a curved shape. This is due to the fact that a tensile force acts on the outer wall of the product, and the inner side is subjected to compression.

Attempts to bend a profile pipe without a pipe bender are associated with the following problems:

• The appearance of cracks in the material. If the wall thickness is small, then metal rupture is possible.
• Crinkling of sides. A similar effect occurs when excessive pressure is applied while passing workpieces through bending fixtures.
• The appearance of internal folds. The greater the height of the product profile and the smaller the straightening radius, the greater the likelihood of such a defect occurring.
• Section break. Occurs when sudden force is applied to the workpiece.
• Changing the section configuration. If the technology is violated, the planes, the longitudinal axis are displaced, and the part is bent in the form of a spiral.
• Reduced metal strength. Such a flaw is a consequence of overheating and, as a result, a violation of the crystalline structure of iron.

It is not difficult to avoid such complications. It is enough to approach the matter competently and thoughtfully.

Methods for bending profile pipes

Dacha owners often have to think about how to bend a profile pipe for a greenhouse quickly, without spending money on professional equipment. Even with financial resources, it is not always possible to immediately find arches of the desired shape and size.

You can use one of the suggested methods:

• Cold pipe bending. It is used when working with small section profiles 10x10 mm and 10x20 mm, with a wall thickness of no more than 1.5 mm. In such cases, the deformation is carried out by the muscular power of the master, and he himself can control the condition of the metal. It is necessary to constantly measure the position of the section horizontally and vertically. The correctness of the work is checked by the template.
• Preheating. A flame source is used in which the workpiece is heated until it reaches a red color. After this, it is bent to the desired configuration. The bent workpiece must be kept under tension until it cools completely. For heating, a gas boiler, stove, blowtorch or country grill with a high content of charcoal is used.

• With internal filling. Sand, machine oil or water are used as filler. It is necessary to ensure that the cavity is filled as tightly as possible. The best effect is achieved by freezing water. Ice prevents the pipe from collapsing under pressure. Tightness is achieved by welding the holes or hammering wooden plugs into them.
• Sector cutting. To do this you will need a grinder with a cutting disc. Triangular slits are made in the profile and the sawn fragments are removed. Then the pipe is bent, and the edges of the cuts are welded with thin electrodes. This method is long but reliable. Its use eliminates bending and deformation.

Given time and creativity, unconventional approaches can be used.

Alternative bending methods

In order for radial bending of profile pipes to bring the desired results, it is necessary to take into account factors such as:

• plasticity of facing material (tin, plastic, monolithic and cellular polycarbonate);
• cross-sectional shape and wall thickness - square products withstand deformation better;
• elasticity of the metal - when cold forming, the workpieces need to be deformed 10-15% more than the required radius.

The following alternative methods for bending rectangular pipes exist:

• Forging. Bending is done by methodically striking the workpiece with a heavy hammer. An anvil is pre-made, the top of which has a rounded shape. The workpiece is rigidly attached with clamps to the base of the anvil. After this, blows are applied to the profile. Care should be taken as Excessive force may cause the product to flatten. It is more convenient to work with segments no longer than 1 m.
• According to the pattern. The basis for placing the part can be a concrete, asphalt or tiled area. The outline of the arc is drawn on it, after which reinforcing pins or thin steel pipes are driven into the ground. The part is fixed to the first pin. As bending progresses, welding is carried out with pins. When the elastic force weakens, the arch is cut off from the pins with a grinder.
• Rental under pressure. To create pressure, a vehicle with side-mounted wheels and without wings is used. The lath is placed in a pre-prepared groove made of steel or concrete. After this, the wheel is methodically rolled along the profile. Axial alignment is controlled manually or by metal guides.

To reduce the likelihood of deformation of the walls of the product, you can insert a thin and long steel spring into it. When heating is used, do not cool hot steel with water. This may cause it to crack or burst. It's better to use working out. When using muscular force, it is recommended to attach a long and strong lever to the free end of the link. This way you can achieve your desired goal with less effort.

Necessary equipment

To bend a profile pipe with your own hands, you must have the following devices and equipment:

• roulette;
• level;
• Bulgarian;
• welding machine;
• protractor;
• sledgehammer;
• heavy hammer;
• blowtorch;
• core;
• marker or chalk.

To achieve an accurate result, it is recommended to use a special tool. The jig is a device for precise calculation and cutting of joined parts. The mechanism is used for marking at the ends of arches, stops, jibs and crossbars. Thanks to the use of a jig, the welding seam is smooth and neat.

Help the development of the channel - like, repost, subscribe to our channel and you will not miss many more useful articles! And visit our website dedicated to self-installation of various pipes.

Source: https://gscomplect.com/kak-gnut-kvadratnye-truby/

How to bend a profile pipe without using a pipe bender - methods and tips

Such pipes have recently been used in construction or repair work no less often than traditional ones (round section). Their profile can be rectangular or square, sometimes in the form of an oval. Such products are universal in use, so they are used to construct not only utility lines, but also various structures (including decorative ones), sometimes of the most complex configuration.

Therefore, such a pipe must be bent. But how and with what? The peculiarity of working with profile products is that the usual pipe bender will not help here. It's all about its rollers and shoes, which are shaped for laying round workpieces. Therefore, it is not suitable for working with parts of a different cross-section.

The easiest way to bend such pipes is on a special machine called a “profile bender”. But its cost is approximately 150 - 180 thousand rubles, and this is not the most expensive mechanism. For domestic use, it is advisable to purchase one of the manual models, the price of which starts from 11,760 rubles. Naturally, when working with such a device you will have to work hard.

But if this is a one-time job, then there is no point in spending money on a product that will then remain unclaimed. Of course, the easiest option is to contact a workshop. But this is not always possible, and it often happens that there is simply no time for this. In such situations, you can use one of the “folk” methods. But you need to take into account that such methods are applicable only to pipes of small cross-sections.

Welding + “grinder”

It is necessary to correctly determine the required bending radius. On 3 sides (lateral and “internal”) along the length of the future arc, cuts are made with a “grinder”. Only one side remains intact, which in this form is an ordinary strip of iron. It won't be difficult to bend it.

After this, the cut areas are “welded” and processed with a grinder. If this is done efficiently, there will be no noticeable seams.

Spring

It is pre-made with a square (or rectangular) cross-section. The size is selected so that it can be inserted inside the pipe without much effort. The wire used is “hard”, steel. In practice, it is taken with a cross-section from 1 to 4 mm. The principle is simple - the larger the “profile” size, the thicker the wire.

Depending on the required bending radius, the diameter of the sample (blank) is selected. First, the pipe is heated with a blowtorch, and then it is bent on a selected form.

Water

A copper profile is bent in this way, but this is done in winter. Water is poured inside, and both ends are “muffled”. After a few hours spent in the cold, such a pipe will easily bend on the blank. By the way, you can bend products made of brass or duralumin this way.

Sand

One end of the pipe is sealed “tightly” (for example, with a wooden chop). Sand is poured inside, which must be absolutely dry and sifted with high quality. “Backfilling” is done along the entire length of the pipe, after which its second end is also “damped.”

A small profile is bent by hand on a blank in a “cold” form. For larger sections, you can also use a flame source (blowtorch, burner, etc.). After finishing the work, the choppers are removed and the sand is poured out.

Some tips

• When working with a square profile pipe, it should be bent to a small radius closer to the end.
• If the chop (wedge) cannot be pulled out, then it is not difficult to burn out such a piece of wood.

Perhaps there are other methods. The main criterion is the quality of bending and the absence of deformation, especially metal tears.

Source: https://ismith.ru/metalworking/kak-sognut-profilnuyu-trubu-bez-trubogiba/

How to bend a square pipe at home? — Machine tools, welding, metalworking

Almost all summer residents and owners of private houses have to face the question of how to bend a profile pipe at home without a pipe bender.

Arches from profile pipes are used in the construction of greenhouses, gazebos, canopies and arched canopies. Purchasing special bending devices or making them yourself is not economically profitable.

They are needed for mass production, not individual production. Let's look at what methods exist for bending profile pipes to the required radius.

What is the problem with profile bending?

The essence of this process is that one side of the pipe is stretched, and the inner part is compressed. Pressure is applied to the workpiece, which may be accompanied by heat, to make the metal more pliable.

Bending a profile pipe along a radius with your own hands is associated with the following difficulties:

• displacement of the longitudinal axes and planes of the part, which leads to misalignment;
• rupture and appearance of cracks on the outer part of the workpiece under the influence of tensile force;
• uneven compression of the inner part, leading to a corrugation effect;
• change in the diameter or shape of the workpiece.

To know how to properly shape steel pipes into an arch, you need to take a number of factors into account.

Influence of material on the choice of bending method

Profile pipes are made in accordance with the requirements of GOST 54157-2010 and have certain properties.

It is necessary to bend profile pipes taking into account the following parameters:

1. The minimum bending radius of the facing material that is planned to be laid on the arches. For cellular polycarbonate, these indicators depend on the thickness and structure.
2. Profile size and wall thickness. Products with a wall height of up to 10 mm can be bent using muscle force. Profiles from 20×40 mm and larger must be bent in a complex manner using pressure and heat or on a machine.
3. Elasticity (plastic moment of resistance). It must be included in preliminary calculations, giving the workpiece a smaller bending radius.

Based on the analysis of this data, a choice is made on how to perform the task.

Bending methods and bending devices

Using available materials and household tools, you can make a bending device at no additional cost.

As for professional devices, their cost can be several times higher than the price of the material for making arches.

Let's look at ways in which you can make bent rectangular arches of an ideal shape.

Cold

Without heating, cold steel is bent if the master’s muscular strength is sufficient for this procedure. As a rule, these are square pipes with a cross-section of 10×10 mm and rectangular pipes with a cross-section of 10×20 mm.

If the walls of the workpieces are thick, then filling the internal cavity with resistance is not carried out. Let's consider the main options for creating arches from metal blanks.

Lever with nozzle

First, a pattern is made with a certain semicircle length corresponding to the specified parameters. It is made from chipboard, plywood, drywall or boards.

After this you need:

• Securely secure the vise to a heavy, stable table. A piece of pipe with a larger size than the workpiece is firmly fixed in a vice;
• perform bending in several stages by inserting the profile into the hole of the section clamped in a vice and applying force to it.

A lever of sufficient length is attached to the bent fragment to create the necessary pressure to deform the metal. During the work, the curvature is controlled by a pattern.

By mandrel

The mandrel is made on a solid base, which is a concrete or asphalt platform or a large workbench. In essence, this is a special template along the contours of which the profile pipe will bend.

Taking into account the degree of elasticity of the metal, the master needs to give the mandrel a smaller radius.

The procedure is carried out in the following sequence:

• the part is securely fixed to the base;
• the end of the workpiece is screwed to one of its edges with wire or clamps;
• the profile is bent until it is given the desired shape.

The template can be replaced with reinforcement driven into the ground. As the pipe deforms, it is successively welded to the pins. After finishing the work, the arch is cut off from the stoppers.

Using internal countermeasures (sand, water)

This method is used when the profile parameters are less than: height 10 mm, width 20 mm, wall thickness 1 mm. Pipes filled with a dense substance retain their shape better, even under strong pressure on a small area of ​​the product.

The use of sand and water guarantees a high-quality result without defects. And this factor is important, given the cost of rolled steel.

The filler must fill the entire volume of the profile pipe cavity. It is much easier to achieve this with liquid. The sand is compacted by vibration and spilled with water. The holes on both sides are welded or tightly clogged with wooden plugs. If heating is used, it is important to leave one side unclogged to allow gases to escape.

Grinder cutting and welding (sector welding)

Cutting with a grinder and welding does not require significant effort. The master needs to be prepared for the fact that this event will take a lot of time. The advantage of this technology is that there is no chance of damage to the profile; its shape can be adjusted throughout the entire bending process.

The work is carried out in the following sequence:

1. A diagram is drawn up. It shows the distance between the cuts and their configuration.
2. Markings are applied to the profile. Using a grinder, triangular cuts are made along it. The cut fragments are removed.
3. The workpiece is bent. If the metal is elastic and unbends after compression, then the joints are immediately fixed by spot welding.
4. The cracks remaining after compression are welded or sealed. After the metal has cooled, the seams are sanded and painted over.
5. The edges on the arch are almost invisible. When laying polycarbonate, small differences are compensated for by a thick seal.

Hot

Preheating is carried out in cases where the profile pipe has a large cross-section or thin walls. That is, it is either impossible to bend it manually, or it is fraught with damage or breakage of the workpiece. Let us dwell on the techniques that are used for thermal bending of rolled steel.

Using a spring and a blowtorch

The spring is needed to prevent the profile walls from being pushed through during bending. In addition, the elastic insert will give the finished product a neat and even shape. It must be strong enough to absorb and withstand the pressure exerted on the profile.

One end of the section is rigidly fixed in the ground or in a vice. Before bending the fragment, it is heated until the metal turns red.

You can cool the bent area only with warm machine oil - water causes the iron to crack and become brittle.

Using a spring and a blowtorch saves the worker from exerting unnecessary effort.

Hot forming

It is possible to give the desired shape to the profile without preliminary internal filling. When heated, steel becomes so soft and flexible that it can be bent by hand, without the use of levers or complex devices.

For this purpose, a convex semicircular stop is made. It must be made of material resistant to high temperatures. A car wheel or fireclay brick coated with clay is best suited for this. The heated part is applied to the template. After this, it bends in one slow and precise movement. After a few minutes, you can continue the procedure.

Tips and tricks

Giving profile pipes an arch shape is a complex process that requires skills in handling household tools and metal.

When making arches, you should adhere to the following rules:

• It is easier and more convenient to work with short workpieces. Before bending, it is advisable to cut the parts into segments 1.5-2 meters long. Subsequent welding will not weaken the strength of the finished arch.
• Heating of the metal should be done slowly to prevent uneven heating and deformation. The resulting scale must be cleaned off immediately, as it causes corrosion.
• Rolled steel cannot be exposed to temperatures above + 800 ºС. This impact leads to the destruction of the metal crystal lattice. The profile becomes soft or brittle.
• All bending actions should be performed slowly, gradually increasing the load.

How much does it cost to bend a profile for a greenhouse?

The cost of services is determined by the status of the workshop, its geographical location and the equipment used.

The average price for bending profiled steel is (in rubles per linear meter):

1. 10×10 — 80;
2. 20×20 — 100;
3. 25×25 — 110;
4. 30×30 — 120;
5. 20×40 — 125;
6. 20×45 — 130;
7. 40×40 — 140;
8. 50×50 — 150;
9. 60×40 — 160;
10. 50×50 — 180;
11. 80×40 — 240;
12. 80×80 — 360;
13. 100×100 — 480.

Cost may vary depending on market supply and demand.

Special devices for bending

In order to achieve high quality of the finished product, you can use factory-made and home-made devices.

Pipe bender

Pipe benders consist of a frame, several rollers, limiters and a drive. The device is controlled manually, by an electric motor and by hydraulic cylinders. In private construction, profile pipes with a wall height of up to 20 mm are used. A manual pipe bender handles their bending.

Conductor

This tool is designed for precise manufacturing and joining of profile joints when cutting with a grinder and connecting arches with vertical, transverse and inclined posts.

Thanks to the use of a jig, the most accurate connection of parts at right angles and a neat seam between them is achieved.

Bending plate

This device is a removable structure installed on a workbench or on the workshop floor.

For fastening, embedded parts or anchor bolts are used. The curvature of the base plate is adjusted with bolts.

After bending is completed, the equipment is removed and the embedded parts are closed with plugs.

Making a bending machine with your own hands

We already wrote about how to assemble a manual pipe bender yourself in a previous article. This is not the simplest device, but it will allow you to quickly bend fairly large volumes of profiles. For assembly you will need 3-5 blanks for shafts, a channel, an I-beam, an angle grinder, a welding machine and a door with a set of fasteners. The photo below shows exactly the rollers we were talking about.

Source: https://stanki-info.com/kak-sognut-kvadratnuyu-trubu-v-domashnih-usloviyah/

How to bend a profile pipe for a greenhouse correctly

Due to the fact that the metal structure is much thinner compared to wood, there is more natural light in the greenhouse. This material is also more technologically advanced.

When constructing an arched greenhouse, the profile needs to be bent. It bends for an arch that runs vertically from the base up, and in the middle, in an arcuate manner.

For example, if you choose a Mitlider greenhouse, the strength of the frame will be ensured by connecting the posts and beams.

In dome-shaped greenhouses, the structures consist of polygonal frames (aluminum/metal), but they are quite difficult to assemble on your own.

The frame material itself is selected “to suit the design” of the entire structure and its dimensions. If you are going to build an arched greenhouse, the frame of which is made of metal rather than plasterboard, prepare:

• flexible rods (for half-arches) - one and a half meters long, in the amount of 12 pieces; 
• for a building 1.8 m high - 10 pieces of rods, the length of which is 2 meters and the diameter is 30 millimeters; 
• To make a frame, you must begin by identifying the holes for the rods; sometimes you need to bend a square pipe, in which the cross-section is 20 by 20 and the diameter will be three meters.

You will need these tools:

• bending machine;
• profile pipes; 
• tape measure, simple pencil;
• Bulgarian;
• welding.

You can make a bending machine yourself; you actually need to bend the profile pipe on it. Scroll it with the handle.

It will take a lot of effort, even when the wall thickness of the material is about two millimeters, because it’s not like folding drywall! If you don’t have a machine, you can bend it with your hands.

Secure the pipes running parallel. Draw an arc of the required radius directly on the ground, attach the product and bend it so that it becomes exactly the same as in the drawing.

The next arc must be bent according to the pattern of the first.

The pipe must be cut into equal parts in advance using a grinder, and then bent according to the sample.

In those places where there were undercuts, process using spot welding. The light and strong profile is quite easy to connect to the planes.

In addition, it is able to withstand a fairly large lateral load.

Using a Pipe Bending Machine

Anyone who has tried to bend a profile pipe is aware that it is very difficult.

It is much simpler and easier to work with drywall, but not in this case! Here a special pipe bending machine or a manual method can help.

Also one of the ways is fire. One part of the pipe is heated, then, using a lever, it is bent at a certain angle.

The disadvantages include the appearance (on completion) - rather unaesthetic and the fact that a lot of physical effort will be required, because this is not drywall!

Of course, using a pipe bending machine you can bend a pipe much more accurately, faster and easier. Holding the handle, the profile stretches along the machine’s rollers, while the other one presses down the material, thereby deforming it.

It is much more “pleasant” to bend a product in this way when it passes through a pipe bender and turns into an arch, moreover, of the radius that was given to it. Using a manual machine, products can be bent to warm up the greenhouse during cold weather.

Make a pipe bender. You will need:

• 3 pieces of roller;
• special bracket with a clamping axis and a lead screw; 
• metal table;
• template and blank; 
• steel pipes with a diameter of 0.7-1.5 cm;
• channel and welding;
• concrete solution.

Bending methods

You can bend pipes for a greenhouse using a cold or hot method. Both options are provided. If you heat it with a gas burner, the plasticity will be much higher.

But if the pipe has a small cross-section, it can be easily bent without exposure to high temperatures. Pipes with thin walls are flexible and easy to bend.

There are no specific recommendations regarding heating materials, with the exception of pipes with a diameter of more than one hundred millimeters.

But if the pipe is square or rectangular, you need to work with them a little differently.

If the profile height is less than ten millimeters, it must be bent cold. If the height is forty millimeters or more, then you can’t do without heating.

Regarding bending material with a height of ten to forty millimeters, everyone decides for himself how it is convenient for someone and in what way, after all, it’s not drywall that needs to be bent! If you have a special device for bending the pipe, then you can do without heating.

 “How to make a pipe bender and bend a profile pipe with it”

A lot of necessary information about a pipe bender to ultimately make a frame for a greenhouse.

Cold method

If the profile height is up to ten millimeters, it must be filled. For this you can use sand, rosin or a tightly wound spring.

You can do this yourself, for which you will need: a bending plate, a vice and a mandrel, a bending profile (you can either make it yourself or purchase it in a store).

Heated

Material that is not amenable to the cold process must be heated at high temperatures. The pipe is first filled with sand to ensure uniform bending and quality of work.

You will definitely need canvas mittens. Trimmings (logs) will be needed for a pyramid-shaped plug, ten times longer than the base.

The base area of ​​the plug itself should be twice the size of the hole it will cover. Try on how the plugs fit, then make longitudinal grooves on one of them, on each side.

On the future bend you need to anneal the workpiece.

Prepare a filler from construction medium-grained sand (it must be thoroughly sifted several times through a sieve with cells of different diameters, first 2 mm, then 0.7 mm).

Next, the filler must be heated at a temperature of 150 degrees Celsius. Plug one end of the pipe with a plug, and place a funnel on the other.

The workpiece must be installed perpendicular to the ground, or at an angle, it all depends on the size. And fill it with sand through a funnel.

Then close the second plug with the end of the pipe through which the sand was poured. Secure the product in a pipe clamp or vice. The welded joint should be on the side.

Very carefully give the required shape to the pipe. In one step, bend it not sharply, but always in a vertical or only horizontal position. Everything worked out.

The plugs can be knocked out (burnt out) and the sand poured out, the material for the greenhouse frame is ready!

 "How does a pipe bender work"

In this video you can see the sequence of actions that need to be performed in order to bend a pipe.

Source: http://srovopros.com/kak-pravilno-gnut-profilnuyu-trubu-dlya-teplitsy/

How to bend a square pipe at home

Almost all summer residents and owners of private houses have to face the question of how to bend a profile pipe at home without a pipe bender.

Arches from profile pipes are used in the construction of greenhouses, gazebos, canopies and arched canopies. Purchasing special bending devices or making them yourself is not economically profitable.

They are needed for mass production, not individual production. Let's look at what methods exist for bending profile pipes to the required radius.

How to bend a square pipe: bending square pipes with and without a pipe bender at home

Bending of profile pipes can be useful in any area related to the construction or installation of structures. After all, their main purpose lies precisely in the construction of supporting structures.

Square pipe

Bending a square pipe is not that difficult, but at the same time this process requires a very careful approach. Each awkward step can simply destroy the integrity of the structure, and then you will have to buy new metal products.

To bend pipes, as a rule, special devices called pipe benders are used. But what to do if there is no such device, but you need to bend a profile square pipe? In such situations, human ingenuity and a garage foreman’s kit come to the rescue. In any case, you can bend the profile without a pipe bender, at home!

Features of bending square pipes

The peculiarity of these products is their square shape. Unlike classic round ones, they can easily be bent at any angle, spending less effort on this process. All thanks to a smaller bending area and a thinner profile.

In addition, they are easily fixed without the use of a vice. The profile can be clamped between two posts, which will be enough for a more or less high-quality fixation.

But often the problem with high-quality bending is the material of manufacture and the cross-section diameter. If the material of manufacture is steel, then there will be little cold bending, because steel is a very strong material. Here you will need a torch or heating element for bending pipes.

The diameter of the section is also important. The larger it is, the more difficult it is to bend the product. That is why it is better to choose a pipe for a greenhouse or for other needs with a smaller diameter, since working with such profiles will be much easier.

During the incorrect bending process, the pipe may become unusable. This happens for several reasons:

• The profile may come off the clamps. This cannot be allowed. Otherwise, bending will occur in different planes, and ultimately the product will be unsuitable for installation.
• During bending, a fold is formed inside the shape. On the one hand, this will not affect the final structure in any way unless it is bent back. In this case, a crack will form at the place of the fold, which is already quite a serious problem.

Fold

• Strong or too sudden pressure on a section of the profile can also damage the integrity of the structure. It may not withstand the pressure and burst at any moment.

Important! All of the above points can be avoided only if the pipe bending technology is followed!

Types of pipe bending

At the moment there are only 4 types of bending. Each method is designed for specific technological features of products. Therefore, not every method can be applied to every profile.

Hot bending

The method is relevant for those who do not have a pipe bender. Bending work in this way is quite labor-intensive, but the result will not take long to arrive.

Heating with a gas burner

The bottom line is this: sand is poured into the pipe cavity. Ordinary river sand, which should be thoroughly sifted to remove flammable elements (wood, fluff, etc.) before starting work. The sand needs to be filled in as densely as possible. After this, both ends of the profile can be closed with wooden plugs to prevent sand from spilling out. Using a gas or gasoline burner, the bend area is heated to a temperature of 900°C. The main thing is to prevent overheating.

You can understand the state of readiness for bending by the color of the metal - it will be red. After this, you can bend the pipe to any angle, using stops or simply with your hands (depending on the thickness and material of manufacture).

The advantages of this method are the possibility of using it at home and the low cost of the process. Disadvantages - an inexperienced craftsman can overheat the metal, causing the profile to burst.

Cold bending

At the moment, this is the most optimal and common way to work with metal surfaces. It does not require the use of fire and is completely safe for others.

The cold process involves the use of special equipment and its absence. It’s worth clarifying here: the pipe can be bent without fire or equipment if the diameter allows this.

Without equipment, it will not be possible to make an even bend, but at the same time this will be enough to, for example, create a 90-degree angle. The profile is clamped in a vice, after which it is bent down/up using a crowbar or a thick rod. The process is long and labor-intensive, but results can be achieved.

There is the possibility of using bending equipment - it is better to take advantage of it. This is the most accurate and safest way. There are 2 types of such equipment:

• Stationary pipe benders;
• Portable pipe benders.

Types of stationary pipe benders

Their main difference lies in the scale of the work performed. With the help of the former, as a rule, thicker and longer products are bent. Such devices are highly accurate and powerful. Portable pipe benders are more compact and, accordingly, are designed for small pipes.

Depending on the modification of the devices, the pipe can be bent up to 360 degrees! The result is a complete circle, which may be interesting for metal surface craftsmen.

All pipe benders have one thing in common - they have thrust rollers. A pipe is placed on them, and bending occurs from its own pressure or from pressure from a special stop. Human effort here is minimal. You just need to watch the bending angle.

Pipe bending along a radius and at an angle of 90°

If the future design of a greenhouse or summer gazebo involves the use of twisted supports, then a stationary pipe bender will be required to perform the work efficiently. Without it, it will not be possible to provide an accurate slope angle without damaging the material.

To bend pipes along a radius, a pipe bender with a designated bending scale is used. As a rule, it is located on the front of the device. The entire work process will be carried out on this scale.

Bending at an angle of 90°

The pipe is laid on the fixing rollers, after which it is clamped with a thrust roller. Using the rotation levers, it is necessary to bend the pipe at an angle of 90 degrees according to the scale. During bending, the pipe will bend into the cavity under the rollers, so there should not be anything superfluous there. As soon as the scale shows 90°, you can remove the stops and pick up the product.

Bending with a pipe bender

Radius bending

This process is practically no different from the process of bending at an angle of 90°. The only difference is that it is now necessary to achieve a different result on the scale. And during operation, it is necessary to periodically change the position of the pipe depending on its length.

How to make a pipe bender with your own hands

In the store, such devices cost incredible amounts of money. Not everyone can afford to just go out and buy them. That is why garage craftsmen found a way out of the situation and began making pipe benders with their own hands.

Here is one of the simplest pipe benders for square pipes that absolutely anyone can make!

The principle of its operation will be hydraulic. The basis is the use of a conventional car jack, which can be purchased at any auto store.

The following components will be required:

• jack (preferably with a lifting capacity of at least 2 tons);
• 4 metal pins that will act as a support;
• metal plates with a thickness of 6 mm for the base and fixing elements of the rollers - 3 pcs.;
• metal rollers – 2 pcs.

The main advantages of the design are its simplicity. Disadvantages - only pipes of small diameter are suitable for work and the maximum bending angle does not exceed 180 degrees.

First you need to assemble the structure using a welding machine. The design should look like an inverted stool. A jack can be inserted into the finished structure, and it is advisable to tighten it with bolts to the base. So that it does not jump off during work.

The rollers are installed last. For them you need to make many holes with which you can adjust the bending angle of the pipe.

The end result should look like the image below.

Do-it-yourself ready-made pipe bender

It must be used in the following way: the rollers are installed in the desired position, the jack is lowered down. The profile is pushed onto the base of the jack above the rollers, so that when the jack is raised, the pipe rests against the rollers. That's it, the preparatory stage is over. Now you can bend it. This must be done using a jack. Which should be lifted until the pipe is bent to the required position.

This device can easily bend an aluminum pipe.

Recommendations from experts and common mistakes

As in any business, beginning craftsmen may encounter some difficulties, which subsequently lead to mistakes. Below are a number of the most common mistakes that beginners make that everyone should avoid.

1. Overheating of the pipe during hot bending. A very common mistake. You can avoid this by using a non-contact thermometer and monitoring the heating temperature.
2. Poor quality fixation in the pipe bender. A poorly fixed product can not only be bent poorly, but also cause injury. It is better to ensure the quality of the fixation before starting work.
3. You only need to use entire profiles! If there is damage, then you should not even try to bend such rectangular pipes with your own hands.
4. It is better to bend a large profile in professional equipment. It will be difficult, if not impossible, to bend such products at home. It is more profitable to purchase already bent square pipes in advance.

Source: https://ZnatokTepla.ru/truby/metody-gibki-kvadratnyh-trub-svoimi-rukami.html

Description of methods for bending a profile pipe at home

Many home craftsmen would like to know how to bend a profile pipe without a pipe bender, without using other special equipment. These are the questions asked by people who are planning to build, for example, a greenhouse on their property, but have little idea how to bend a profile pipe at home.

Such structures are made from bent pipes, since they transmit a lot of light and are highly stable and durable when compared with other devices. It may seem that bending metal is very difficult, but if you understand this issue , then it is quite possible to effectively perform this procedure yourself and without the use of special tools.

Difficulty in bending profiles

The essence of the process of bending rolled metal is to give the profile a partial or full bend. This operation is usually performed in two ways : by applying pressure to the pipe or by heating a certain area in the area where the bend needs to be made.

As a metal pipe bends, two forces act on the surface of the metal:

1. The compressive force that falls on the inside of the bend.
2. The tensile force to which the outer part is subjected.

It is precisely the influence of such multidirectional forces that causes various difficulties that are typical in the process of bending any metal pipe.

Common Problems

When bending, the material may lose its alignment, and this will lead to the fact that some areas will be located in different planes.

The wall, which is located on the outside of the bend, will be subject to strong stretching, and therefore may not withstand any loads and simply burst.

The inner wall is also subject to compression, so it is covered with folds that resemble corrugation in shape .

Many people who try to bend a pipe on their own for the first time, instead of giving it the required shape, simply crush the product and ruin it.

To avoid such problems, it is necessary to take into account not only the characteristics of the material, but also geometric parameters, such as:

• Wall thickness;
• section dimensions;
• the radius to which the bend must be made.

If you have information about all of the above, you can choose the appropriate pipe bending technology. As a result, the material will not wrinkle or get a corrugated surface.

Profile accounting

Profile pipes include products that have different cross-sectional shapes:

• square;
• round;
• flat-oval;
• oval.

Even with this variety, to build a greenhouse or shed, a rectangular or square pipe is usually used. This is explained by the fact that it is much easier to install the outer covering on flat walls.

A large number of profiles are sold in stores. There are different geometric parameters, the main ones of which are cross-sectional area and wall thickness. It is also worth looking at the plastic capabilities of the material. This indicator will show the minimum acceptable radius of curvature and will help determine the radius to which the pipe can be bent so that it does not deteriorate.

To determine the minimum bending radius parameter, you need to know the profile height. If you are going to bend a profile pipe that has a rectangular or square cross-section, then you should follow some recommendations.

If there is a profile no more than 20 mm, then it must be bent in those areas whose length exceeds a value equal to 2.5 xh (h is the height of the profile).

If the product profile exceeds 20 mm, then it can be bent in areas whose length is 3.5 xh or more.

These recommendations will be useful to those people who are going to bend a metal profile with their own hands to make a rack, canopy or other similar structures.

But it should be borne in mind that for high-quality bending it is also necessary to take into account the wall thickness. A product whose thickness is less than 2 mm is completely unsuitable for bending, and therefore it is necessary to choose a thicker structure.

If the wall thickness is less than 2 mm, then it is better not to bend the pipe, but to use welding to connect the parts.

If you need to bend a pipe at home that is made of carbon or low-alloy steel, you need to take into account a number of nuances. Such metals, after bending, can spring back and return to their original position, and therefore such structures must be re-checked using a template.

The amount of springback is characterized by such a parameter as the moment of resistance - Wp. This parameter is indicated in the construction documentation. And the lower it is, the less likely it is that the profile will return to its original position during bending.

At home, you can bend metal using heat, as well as in a cold state. Heating is usually carried out using a gas burner, then the ductility of the metal will significantly increase, and therefore much less effort will be required for bending.

Before bending, only pipes with a cross-sectional diameter greater than 10 cm should be heated. If you need to bend square or rectangular structures, then you should only rely on your own experience and the advice of craftsmen who have already been involved in such an operation. If the profile height is no more than 10 mm, then it is not necessary to bend it using heat. If the profile is larger than 40 mm , then heating is required.

If the pipe is small in size, it can be bent in a cold state using hand tools. To obtain a workpiece with a small bending radius, you can use a stationary plate with stops or a vice, as well as a roller device. If a large radius of curvature is required, then you need to use fixed mandrels or plane-parallel plates on which the part can be fixed.

When hot, the metal must be bent only if the profile height exceeds 40 mm. Heating is carried out using a blowtorch or gas burner flame. The pipe should take on a cherry-red hue. The length of the red section should be approximately 6 pipe diameters.

Of course, the easiest way to bend is to use a pipe bender; with it you can very easily cope with the task. If there is no such device, then it is necessary to conduct preliminary tests on an unnecessary piece of metal.

Then it will be possible to decide whether the pipe should be heated or whether this is not necessary. One end of the pipe must be clamped in a vice, and a tube with a large internal cross-section must be attached to the other.

If you can bend metal with such a lever , then the process can be carried out without heating.

Preheat

In order to bend a pipe yourself using the hot method, you must first fill it with sand. This way the bending will be uniform and of high quality. The metal will be very hot, and therefore all work must be carried out with special gloves.

Bending is carried out in the following sequence:

1. Both ends of the pipe are plugged with plugs. The length of the plugs should be 10 times the width of their base.
2. After the fitting of the plugs has been successful, it is necessary to make 4 longitudinal grooves on one of them, through which gas vapors that accumulate inside when heated will escape.
3. The area that will heat up must first be annealed.
4. Medium grain sand should be poured inside. If you don’t have good cleaned sand, you can take any from the playground, but first you need to sift it through a good sieve to remove all the small pebbles.
5. Preparatory sand must first be calcined at a temperature of 150 degrees Celsius.
6. Before filling the sand, one end of the pipe must be plugged, and the plug must be inserted into the second end only when all the sand is completely inside. To fill the pipe completely with it, you need to tap on the walls of the product. To do this, it is better to take a wooden or rubber mallet.
7. Now you can close the second plug.
8. The area that will be heated must be marked with chalk.
9. The pipe is secured in a vise with a template or in a special clamp. Do not clamp the weld if there is one, as it may burst.
10. The area that was marked with chalk is heated red-hot using a burner. Then they carefully begin to bend the pipe in one step, applying enough force.
11. When the metal cools, the product must be compared with the template. If everything is fine, then plugs and sand can be removed from the pipe.

This method can be easily applied at home, and should be used if there is a need to form a single angular bend. It is better to avoid repeated heating of the material , since strength will be lost, and this will be detrimental to the arched structure.

Bending without heating

You can bend the pipe without heating with or without filler. Do not fill a pipe with sand that has a profile height of no more than 10 mm.

If the pipe is small, then instead of sand you can fill it with a steel spring, which will ensure uniform deformation. You need to choose a spring so that it fits inside freely, but sits there tightly enough. To avoid problems with removing the spring after the operation, it is necessary to attach a wire to the extreme link.

The bend is obtained using simple devices such as a vice, bending plate or mandrel.

It is much easier to use a manual pipe bender, which has a round profile. Working rollers are attached to this device, the shape of the recess in which corresponds to the profile of the pipe .

A profile bending machine, which you can purchase or make yourself, is very effective in bending.

Bending devices

Cold bending can be performed using the following devices:

1. If the pipe is soft and steel with a profile height of no more than 10 mm, then you will need a flat plate with holes where the stops will be inserted. Using these pins, bending will be carried out according to the required parameters. This method has disadvantages: the bending is not precise enough, and when applied, a large amount of physical force must be applied.
2. If the profile is 25 mm high or more, then roller devices must be used. The pipe must be firmly fixed in a vice, and the force must be applied using a special roller. Such a device will allow you to get a better bend, but it will also require a lot of effort.