What Is The Best Way To Bending Angle Iron?

How to reduce the flat part in bending angle?
Five Factors That Influence the Bending Angle Iron Process.
Greatest Load Bearing Aspects of angle iron.
This article solves the above question for you. And provide more knowledge about angle iron roll bending.

What is the difference between Angle Roll Bending and Angle Bending ?

What is angle bending?

It is a metal forming process used to form angle iron to a specific degree or angle. It can sometimes be used as another word for angle roll bending. Both refer to the metal forming processes in which angle irons are formed to a specific degree, radius or curve.

angle bending machine
hydraulic angle bending machine
angle banding machine

Angle bending (aslo called angle ring rolling or angle rolling) is a metal forming process used to form angle iron to a specific degree or angle. It can sometimes be used as another word for angle roll bending. Both refer to the metal forming processes in which angle irons are formed to a specific degree, radius or curve.

What is angle roll bending?

angle ring rolling machine
angle ring rolling machine

Also called angle rolling or angle ring rolling, it may be used to form or bend Angle iron into curves at specific radiuses, to form arcs and or rings.

Generally angle steel bending differs from angle iron roll bending in that it is more concerned with forming the angle steel to a specific angle or degree, rather than a curve or radius.

Angle roll bending

Roll-bending is a process whereby we obtain cold process deformation with a wider bend radius that theoretically can range from 5 times the cross-section to infinity. To achieve this process, the equipment used consists of angle roll-bending machines.

The steel angle is made to pass through a set of three rollers that, after one or more passages (depending on the difficulty of bending), will form an arch with the required radius of curvature. Roll-bending is, generally speaking, a simpler process than bending.

working principle

It works by pushing the angle iron through, normally, three rollers – two on one side of the angle iron and one, between them, on the other. If the rollers are lightly resting on the angle iron then it will clearly just pass through them without bending, but as the roller pressure is increased the angle iron will begin to deform, becoming concave on the side of the single roller as the two outer rollers try to push it around the inner roller. The greater the pressure the tighter the bend.

advantage & disadvantage

  • The particular feature of this type of mechanical process is that a single machine can produce different bend radii on the same angle iron, permitting the creation of complex geometrical shapes.
  • The disadvantage of roll-bending is the fact that in order to achieve a valid grip and begin the roll-bending process, the machine requires a portion of additional material at the beginning and end of the angle iron. This necessitates an increase in the total quantity of metal needed to roll-bend the angle iron.. We called it is unbent flat or flat part of roll bending angle iron.

unbent flat of roll bending angle iron

Again, typically a roll shop that bends a small workpiece on a large section bending machine must factor in a long flat section, which increases material costs.

After bending due to the position of the rollers on the angle steel inevitably remains a flat angle at the ends of the angle iron. This flat part is approximately half the length of the gap between the centers of the lower rollers.

Although the appearance of a straight part is considered to be a flaw of symmetrical roller with 3 roll section bending machine, their simple structure, comfortable use and low price still make them the most wanted model of roll profile metal section bendind machines.

How to reduce the flat part in bending?

In addition, there are methods which we can use in order to easily eliminate this problem. You can find some of them below:

Pre-bending:this solution involves bending the edges of the work piece on a press brake before the roll bending process.


Adding a “base” for the work piece during the pre-bending: this method involves the installation of a “base” together with a workpiece designed for bending and performing the edge pre-bending process on the circular bending machine itself. The application of this method should take into account the possibilities of the circular bending machine and calculate the strength of the applied force on the “base” and the workpiece.

BIT’s section bending machines have independent motion of the two side rolls allows the operator to minimize the sacrificial unbent flat sections on the workpiece.

But because the BIT angle rolls (profile bending machines) move the way they do, an operator can move a joystick or push a few buttons on the control to reconfigure them into a smaller-machine orientation. Beyond this, operators can fine-tune the roll position to minimize the unbent flat even further.

What is Angle Roll Bending Process?

Angle roll bending Processmay also be done with both legs in, and may also be done with both legs out.

angle rolling leg out (easy way)
angle rolling leg out

Angle rolling leg-out: rolling can be done with the leg out which is commonly referred to as rolling the “easy-way” of angle bending.

angle rolling leg out (hard-way)
angle rolling leg out (hard-way)

Angle rolling leg-in: rolling process of angle iron can be done with the leg in, which is often times referred to as rolling the “hard-way” of angle bending.

The angle rolling process may also be done with both legs in, and may also be done with both legs out. Bending process can be done on unequal leg angle iron as well, the end user should specify what leg needs to be in or out after rolling.

How to choose right a angle roll?

Whether operators are bending angle iron, tool choice is critical. The tools need to fit the profile yet not be so tight as to negatively affect workpiece shrinkage and growth. A tool that’s too tight can cause localized distortion and, at worst, actually gouge the material surface.

When operators need to bend an open profile like an angle , they have fewer distortion-mitigating tools at their disposal. Beyond tool choice and fit-up, angle bending machine must choose a correctly sized machine, one with sufficient forming tonnage and adequate grip lengths—enough to provide the needed leverage to reduce distortion, but not so long that they will require an excessively long sacrificial straight section, a long sacrificial flat section becomes expensive scrap, reducing the roll shop’s competitiveness.

What you need to know before bending an angle iron?

Six parameters

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

  1. Degree of bend
  2. Radius of the bent section
  3. Chord of the bent section
  4. Arc length
  5. 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.

Five Factors That Influence the Bending Angle Iron Process

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 machine 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.

How To Bend Angle iron?

Angle irons can be curved by hot and cold bending processes, but cold roll bending is the simplest and produces a quality, uniform product.

BIT’s angle rolling machine can also bend all types of angle as well; including aluminum, stainless and carbon steel. Carbon angle (mill produced) is classified as ASTM A36 resulting in a yield point (PSI) of 36,000 minimum.

Angle roll bending video

Angle iron is bending
Angle iron flange

What is Angle Ring Flanges ?

Steel Angle Flanges are pressed or rolled and used widely in joining ductwork together in dust and fume control work.

Angle iron

Construction, aerospace, automotive, railroad, furniture, HVAC, hardware and storage operations all make use of angle irons. Materials that are used in angle irons include iron, steel, brass and aluminum.

Iron and steel angle irons are the most common, but brass and aluminum are also used in angle iron fabrication. Brass, for example, is used as a light load bearing element when the element will be highly visible.

Greatest Load Bearing Aspects of angle iron

angle iron is stronger than non-structural steel because the two perpendicular flanges work in conjunction to give angle iron cross-sectional structural integrity, resistance to bending from pressure applied from the top or bottom, left or right.

The two flanges that make up the angle create a compound area. A compound area is the location of the axis of a piece of structural steel that is most resistant to the moment of inertia. The moment of inertia is when a static body begins moving around an axis.

The compound area is the most resistant load bearing area of a piece of structural steel — the area most resistance to the moment of inertia. In angle iron, the compound area is located in the trough between the two flanges.

But the physics of angle iron are not as important as the end results.

Layman’s Explanation of angle iron’s Strengths and Weaknesses

Angle iron is relatively resistant to the moment of inertia when the load is applied the top, bottom or either side. However, when pressure is applied in a manner that rotates the angle iron around the axis of the compound area, it will fail with the application of less pressure than when the pressure is applied around the cross section.

In other words, when angle iron is twisted from one end or the other, that is when its structural integrity is most vulnerable. Simply, angle iron is hard to bend, but easy to twist.

Implications of angle iron’s Strengths and Weaknesses

Angle iron works extremely well when used conjunctively. By welding pieces together at 90 degree angles and bracing the angles of the welds with short pieces at 45 degree angles, angle iron’s susceptibility to twisting is greatly reduced.

That means angle iron is a sound and solid material to use for the framing of:

  • crates and boxes
  • cages
  • load bearing support structures
  • free-standing, load-bearing frames

Angle iron is not good to use to span large distances, to support heavy loads as individual units or in any manner that twists the iron such as:

  • Fence posts
  • Light poles
  • Lean-to supports
  • Home-made ladders
MS angle roll

 Simple operation, small size and complete functions. It is also a multi-functional section bending machine, which can roll various profiles by changing the mold.

angle roll
  • Max . Section (mm): 30×4-80×10

More detailed parameters

W24s angle roller

W24 angle bending machine can roll bend angle iron into circle or arc.

angle rolls
  • Max . Section (mm): 80×10-200×30
  • Min.bending DIA(mm): Φ1000-Φ8000

More detailed parameters