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What is angle iron?

Angle iron is a common standard structural steel shape. Angles are L-shaped cross-sections made by hot or cold rolling at the mill.


The basics of bending are the same for all materials in that certain information is required to produce an accurate part:

  1. Degree of bend
  2. The Radius of the bent section
  3. Chord of the bent section
  4. Arc length
  5. The Slope of the bent section
  6. Tangent lengths

It isn’t necessary to know all six parameters. However, at least three must be known to produce a bent section.

W24S-250 Profile Bending Machine
3 roller angle roller


After the information is collected and analyzed, the appropriate method of bending for angle iron is chosen.

  1. Rotary draw bending
  2. Induction bending
  3. Roll bending
  4. Increment bending
  5. Compression bending

As with all bent parts, the customer’s tolerances and appearance requirements help determine the proper method.


Several tips can help to ease bending square or rectangular material and reduce the amount of distortion in bent sections.

  1. Method of Bending. This is a key factor in controlling distortion. A correctly chosen procedure can help to produce consistent tolerances and accurate parts. Design distortion and material size are important factors for determining the bending method.
  2. In many cases, there is no better factor than experience. Many trained bending artisans know what is required to produce an acceptable product.
  3. Size of Material. Larger material bent to a smaller radius has a greater chance to distort than smaller material bent to a larger radius. Design and planning are necessary to help solve bending problems before they arise.
  4. Tooling. After the parts have been designed, the method of bending has been chosen, and procedures to bend to proper tolerances are established, the angle roll bender must be set up with the proper tooling.
  5. Decrease the friction between tooling and material to be bent. When friction is reduced, material flows smoothly through the bending equipment, allowing the machinery to perform its designed operation efficiently.

Bend Angle Iron Flange

A major bending (rolling) angle product is the angle ring. The majority of angle rings are also called angle flanges. Angle flanges are rolled leg out and are commonly provided with or without bolt holes.
angle roll
angle roll machine

How to bend an angle flanges with an angle roll?

Common types of curved structural steel are angle rings or angle flanges. Angle steel rings, usually made of carbon steel, stainless steel, or aluminum, are made by rolling a piece of structural angle steel into a ring and then welding the two ends together.

Typically, the ring is rolled with the horizontal leg radiating out from the center to create what is called a “leg-out angle ring” (as opposed to a “leg-in angle ring” or “off-axis” angle ring.)

These rings are commonly manufactured to standard diameters, but they also can be made to custom specifications. They are used as flanges to connect pipes or to connect to equipment such as a fan. The flanges can be welded together or bolted. In this latter case, the angle iron flanges are provided with bolt holes once again either with standard sizes and locations or with special patterns.

The holes can be put in the angle by several means: drilled, punched by a mechanical or hydraulic press, or punched or drilled by automated equipment. For connection purposes, it is important not only that the holes be located with the correct bolt circle and spacing but also that the bolt circle is concentric with the angle ring.

Large angle rings can be made by connecting ring segments. Ring segments are rolled and commonly cut to length and fitted up into full rings before the holes are put in. The holes can be drilled or punched. After the holes are put in, the ring can be shipped “as is” or cut apart again. In this last case, the ends to be connected are often matched and marked for reassembly. This method is sometimes required when the completed ring would be too large to ship.

More Angle Bending Information (Video Etc.)

Angle Bending
Angle Rolling

How to bend an angle iron with an angle iron roller?

Angle iron has high strength, stiffness, toughness, and ductile properties. However, it does not actually bend very easily. The most natural way to bend an angle iron is the apex in or out but most angle rings are rolled being in or out. What happens is that the bending causes the angle to twist.

The reason is that the vertical leg of the angle is being bent the “easy-way” or like a belt, while the horizontal leg is being bent the “hard-way” like a washer. The twist is caused because the neutral axis is somewhere between the two legs. All the material inside the neutral axis compresses while all material outside the axis stretches.

bent angle iron profiles
Bent angle iron

As anyone who has tried to bend a structural angle has experienced, it is difficult to roll the member perfectly square. Angle bending causes the metal section to twist because the easiest way for it to bend (the weakest section modulus and moment of inertia) is either apex-out or apex-in and not leg-out or leg-in.

Consider what is happening when we try to bend an angle leg-out. The vertical leg of the angle is being rolled the “easy way;” the horizontal leg the “hard way.” But because the two legs are connected, the center of mass / neutral axis is somewhere between the two legs. Any material inside the neutral axis undergoes compression. Any material outside the neutral axis sees tension or stretching. The stretching is limited to about 25% elongation or strain. The compression limit is trickier to define because it will buckle/ripple long before the ultimate compressive strain of the material.

Leg-in angles are the hardest to roll, partly because the thin innermost edge is under the most compression (because it is farthest away from the neutral axis). Often we see an offset in the vertical leg.

With the PBH series Angle Iron Roller, however, we can avoid all this bad behavior and end up with perfectly square rings.

angle roller cost and angle roll machine price in 2022

Our angle iron roller price is lower than our peers’, and our angle roller is high quality, we have our own angle roll machine manufacturing factory, all products are factory price, there is no middleman markup, we accept both small angle rolling machines (MSH-50) customer and large angle iron roller (PBH-700) wholesale customer, angle rollers and section rolling machines for sale online.

If you have any questions, please contact us by email, we can give you efficient solution and low cost quotation, your inquiry will be highly appreciated.

List of our products:profile bending machine
Must know section bending information:practical guide to the section bending of various metal profiles