Structural shapes (H beam) generally fall into one of two main categories, load-bearing or architectural, and fabricators have two primary ways to bend them.
Cold bending: roll bending, BIT section bending machines can be equipped with a traction unit that, when bending beams the hard way, prevents deformation of the web section.
Hot bending: induction bending
Bend and material integrity is the principal consideration for load-bearing structurals, and physical appearance is most important for architectural shapes.
H Beam & I beam
I-Beams or as they are sometimes known, Junior Beams or S-Beams are mostly made from structural steel and are often used in the industrial construction sector. These structural I-Beams have various applications within the construction industry but their most popular are building a framework or other general structural support purposes.
The main difference between I-beam and wide flange is that I-beam has tapered flanges while wide flange has straight flanges.
In building construction, a beam is like a mini bridge in a structure that carries a load. The load may be a brick wall or the floor or roof of a building.
Also, read: H-BEAM VS I-BEAM: WHAT ARE THE 17 DIFFERENCES?
Structural beams are referred to as either I beams or H beams because of the shape of their cross-section. Both H and I beams are capable of resisting shear forces and are extremely resistant to bending. The flat, horizontal sections of the beams are called flanges. The middle, vertical part that connects both of the flanges is called a web.
The function of the web is to resist shear forces that may cause breakages or collapses
I beams also have multiple fillets where the web connects in a curved angle with the flanges.
Beams and wide flange are both bent by BIT series beam bending machine ( profile bending machine ), from the very small sizes to the very large sizes.
- I-beams, so called because their shape resembles a capital “I,” are also known as S-beams or Junior Beams. Their flanges are tapered for greater strength. They are commonly used in industrial applications, and commercial and residential construction.
- W-beams resemble I-beams, except for a straight non-tapered flange. Used in all steel construction markets, these beams are also known as “wide flange.”
- H-beams are usually longer and heavier than I-beams, with longer flanges that resemble a capital “H.” Their webs and flanges are often the same thickness. You’ll find them in commercial and residential construction, bridges, and in heavy machinery bases.
- S-beams are the same shape as I-beams, save for a sloped section on the inner part of the flange surfaces. Also known as American Standard Beams, they are predominantly used in construction.
Cold bending beams
BIT H & I beam bending machine
BIT section bending machines can be equipped with a traction unit that, when bending beams the hard way, prevents deformation of the web section.
How to minimize the unbent flat of bending beams?
The BIT section bending machine independent motion of the two side rolls allows the operator to minimize the sacrificial unbent flat sections on the workpiece.
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.
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.
BIT section bending machine the adjacent 3D guide roll on either side are connected not to the rolls themselves but to the machine frame, so they’re free to move in various positions, always in proximity of the bending rolls, to provide the ideal workpiece support as the job dictates.
Cold bending beam process
This structural section has wide application in buiding and industrial uses, similar to the universal beam.
BIT series profile bending machine ability to bend wide flange and H-beam the easy way (against the weak axis) and the hard way (against the strong axis).
Section bending machine can bend all types of beam / wide flange including aluminum, stainless and carbon steel.
I-Beam and wide flange are specified in similar fashions.
The most common bending method is a roll bend or pyramid bends method. Straight material is inserted into the rolls; the rolls are then moved horizontally to put the desired radius into the material. The material can also be bent incrementally hot or incrementally cold. This is where small sections of material are bent at one time. When finished the section has a smooth curve to the bent section.
Other tools that sophisticated shops use to bend wide flange and I-beam are a web stretcher and mandrels. These tools are critical to use when bending the hard way as they keep the critical web from buckling or distorting.
Notes: When rolling steel beams, it is important to consider distortion.
Cold bending H and I beam
Just as certain types of machines are designed to bend tube and pipe, special types of machines perform H beam bending.
The most practical, accepted, and economical way to make large-radii bends generally is to cold-roll the material. Many variables have a bearing on the type of equipment you should choose, including wall, flange, and leg thickness.
For large-radii bends, cold rolling achieves the desired radius with a minimum number of passes. Because of their size, wide-flange beams can be cold-rolled as well. The larger the radii, the easier cold rolling is.
A 36-inch wide-flange beam can be bent with minimal distortion. Of course, it requires a heavy piece of equipment to make these bends. In addition, it is possible to camber beams up to 44 in.
Induction bending (Hot bending) H beam
In induction bending, an electrical coil conforming to the shape of the material being bent is wound around the workpiece. This coil is specially built, and a different shape is required for each different material shape.
With only a minimum amount of clearance between the coil and the section, uniform heat is induced into the workpiece. This heat is obtained from an electrical unit capable of producing high ranges of kilowatts. The larger the unit and bending machine capacity, the more kilowatts are needed to produce enough heat to bend the workpiece.
This heated area is controlled so that the heat coil induces only a narrow band of heat into the workpiece. This narrow band is where the actual bend takes place. A coil mounted around the workpiece delivers a water spray to cool the material immediately as it is bent.
The heated bending area then is the only malleable portion of the piece, so it is the only area that will bend. An air coil is needed to remove the water in an even flow to control the heat in the bent area uniformly. Some of the parameters you must maintain during the induction process are temperature, cooling water, airflow, and speed (inches per minute, IPM).
The machine has a bend arm that is adjusted to the required radius. This arm is clamped to the end of the workpiece. The workpiece extends through the coils where it is clamped to the pushing device. Normally, this is a hydraulic push ram, although some machines are equipped with a push clamp that is gear- and chain-driven. As the hydraulic ram pushes the workpiece through the heated area, the clamping arm pivots, swinging the piece around to the desired preset radius.
How to bending the H beams
As suggested by the name, the process relies on induction. The H beam (metal workpiece) is placed inside of an induction coil, which, when turned on, heats localized sections of the H beam to temperatures ranging between 1750° F to 1850° F. The exact sections depend on the part design and the exact temperature depends on the base material. As each section reaches the correct bending temperature, the machine slowly moves the H beam through the induction coil as a fixed radius arm mechanism applies the necessary force to bend the workpiece at the heated area. When the H beam exits the induction coil, it is immediately quenched with water to minimize thermal expansion.
This process can take up to an hour since it must occur gradually to avoid snapping or deforming the structure.
Benefits of Induction Bending
Compared to other methods, induction bending offers a number of advantages, including:
- Smaller tooling requirements: does not need dies or mandrels to produce bends.
- Lower material costs: machines allow manufacturers to create standard bent shapes from straight materials as required, which enables them to take advantage of the lower material cost. Additionally, they can save on storage costs since they no longer need to keep standard bends in stock.
- Cleaner operations: does not require the use of lubrication. Additionally, the water used for quenching operations can be recycled.
- Stronger parts: eliminates the need for welds at critical structural points, which improves an assembly’s ability to withstand pressure and stress.
About roll bending of the aluminum H beam
Consider the aluminum H beam (structural shape) in picture below, being bent in the direction shown by the black arrow. All legs are forced toward the center (as shown by the red arrows in the figure)—a tendency particularly noticeable on structural joist-type sections.
If this were a conventional carbon steel beam, the flanges would be pulled in the opposite direction, placing tension on the web and, therefore, keeping the web flat. This technique generally isn’t suitable for aluminum, though, so other techniques come into play.
Tees (Beam Splitting)
You can split any size wide flange into “T” (Tees) and straighten, in our profile bending machine, to mill tolerances.
PBH Series H/I beam bending MACHINE
BIT beam bending machine can bend H beam and I beam into circle or arc.
- Max. section. easy-way (mm): 120-700
- Min. Dia. easy-way (mm): Φ600-Φ6000
- Max. section. hard-way (mm): 120-500
- Min. Dia. hard-way (mm): Φ4000-Φ40000
Note: A larger size beam roll bending machine can be customized
CBM beam bending machine
CBM series profile cold bending machine has simple structure, reliable performance and low price. It is the most economical choice for outdoor engineering bending beam.