What is Bending Machine?
Let’s first read the definition of this term on Wikipedia: “A bending machine is a forming machine tool (DIN 8586). Its purpose is to assemble a bend on a workpiece. A bend is manufactured by using a bending tool during a linear or rotating move. The detailed classification can be done with the help of the kinematics.”
According to this definition, it is just a proper noun for a bending machine. In fact, a bending machine has another name: press brake or just called brake. The source brake comes from the Middle English verb (to brake), which means “to bend”.
However, the rapid development of metal forming technology in modern times has led to more types of bending machines, and people even give them the names of professional individual metal materials, such as plate bending machines, square tube bending machines, flat steel bending machines, profile bending machines, and aluminum bending machines. machine and so on. In this case, there are too many bending machines and various types in the world of metal forming, so in official documents, manufacturers are still accustomed to dividing these profile bending machines by the bending principle.
In one of our previous articles, we introduced a total of 12 kinds of metal bending processes that currently exist, now let’s review them, or you can click here to get them.
12 Kinds of Metal Bending Proceses
- Air bending: It is the process of forming materials by pressing a punch into the material.
- Bottoming: Is sheet metal pressed against a bottom die featuring a V shape.
- Coining: the punch and the workpiece bottom are on the die.
- Three-point bending: Is a relatively new bending process that requires the use of an adjustable die.
- Folding: Changes the shape of sheet metal parts by cold forming along straight lines, simultaneously over the entire length.
- Wiping: Aka edge bending, is performed by holding the sheet between a pad and die then sliding the wiping flange across the face pushing and bending the sheet metal which protrudes from the pad and die.
- Rotary draw bending: Rotary draw bending is a cold bending method where the member is clamped to a rotating bend die and drawn around the bend die.
- Compression bending: an older method of bending, it is often used on construction sites for bending electrical conduit or rebar.
- Roll bending: Roll bending or roll curving is use the 3 rollers to designate the manufacture of sheet-metal parts(steel plate or aluminum profile, etc) that are rolled or curved into cylindrical shapes or shapes that have a smooth radius associated with them.
- Elastomer bending: the bottom V-die is replaced by a flat pad of urethane or rubber. As the punch forms the part, the urethane deflects and allows the material to form around the punch.
- Stretch bending: is part of metal forming where the metal is bent or “stretched” to create perfectly shaped parts.
- Roll forming: is the continuous bending of a long strip of sheet metal (typically coiled steel) into a desired cross-section.
Top 10 Types of Bending Machine
Coining, Bottom, Wipe, and Air Bending
A Surprising Fabrication Process - Press Brake Forming: Press brake metal forming is one of the oldest mechanical metal deformation processes. During this process, a piece of metal is “formed” along a straight axis. The three types of press forming most often employed by metal fabricators include air bending, bottom bending, and coining each requires different strategies in tooling and press brake operation.
Wiping bending(aka edge bending) is suitable for machinery such as cornice brakes, and press brakes.
Type 1#: Brake Press/Bending machine
Press brakes are fabrication machines used for bending sheet metal, it has a Ram fitted with a punch that forces the material being worked into a die. The material is placed over a V-shaped die and pressed into from above by a punch. Press Brakes can also be operated by manual or CNC Controls. These machines can bend sheet metal work from just a few inches to some that are many feet long.
Press brakes can bend simple and complex parts, and they are used in a variety of industries ranging from automotive and aircraft to housing and cabinets.
Type 2#: Folding Bending machine
Folding bending machines (folding bending process) are used to give a sheet metal product its shape. They are easily identified by their large support tables and swinging “folding beam”, which bends the flange while the workpiece remains flat on the support table. Folding machines operate in a similar way as historic handbrake bending. Depending on the level of automation, a workpiece is referenced against CNC-controlled backstops that are nested in the support table. A clamping axis, called the upper beam, is driven by servo-electric motors to a specific position to hold the blank in place. Once the material is clamped, the iconic swing-beam folding arm will drive in an arc, carrying the flange to the desired angle. On manual machines, this referencing happens for each bend; on semi-automated systems, this reference step happens only once per side; on fully-automated solutions, this reference occurs only once per part!
The main difference between a folding bending machine and a press brake is how they handle a workpiece. On a press brake, the flange is gauged and the rest of the part is rotated up. On a folding machine, it’s the other way around—the part is gauged and supported on the sheet support system and the flange is turned up.
Roll bending is a cold bending process whereby we obtain cold process deformation with a wider bend radius. Roll bending process in which tubes, steel/aluminum plates, and metal profiles are fed past contoured pressure rollers resulting in a continuous bend, will form an arch or circle with the required radius of curvature.
A roll bending machine is a mechanical jig having three pressure rollers used to bend a metal profile(tubes/pipes, steel/aluminum plates, metal profiles, H-beams, angle irons, etc) into a circular arc. The pressure rollers freely rotate about three parallel axes, which are arranged with uniform horizontal spacing. Roll bending pushes an extrusion around three different pressure rollers placed in a triangular shape. The pressure rollers are adjusted to form a precise angle, up to a 360-degree rotation, that can roll horizontally or vertically.
Generally, there are three types of bending machines that apply the roll bending process, they are: Plate Rolling Machines, Profile Bending Machines(aka section Bending Machine, anglle roller), Aluminum Bending Machines(aka Aluminum Profile Bending Machines)
Typec3#: Aluminum Bending Machine
Aluminum profile bending machines (also called aluminum benders) are used to form aluminum profiles. It can be bent in many ways, but the most commonly used is roll bending. More Detail: Aluminum Bending Machine, Extrusion, Spiral Roll – BIT
Type 4#: Plate Bending Machine
The Steel Plate Rolling Machine (also named Plate Roller, Plate Bending Machine, and Bending Rolls) is a device for the radial forming of flat sheets. The Hydraulic/Mechanical Plate Rolling Machine works similarly to a Profile Bending Machine. However, its design is much simpler.
The Plate Rolling Capacity of CNC, PLC Steel Plate Rolling Machine: : Bending thickness from 2.00mm to 160.00mm, plate rolling width from 1,000.00mm up to 10,000.00mm.
Read More: CNC Steel Plate Bending Machine – Best Buyer’s Guide
Type 5#: Profile Bending Machine/section Bender
Profile bending machine(aka section bending machines, and angle roll) is equipment for the radial forming of metal profiles. It works similarly to a plate rolling machine. However, its design is much more complex. It is equipment that cold-bending metal profiles according to the principle of the three-point circle. Profile benders can curve a wide variety of metal(such as carbon steel, stainless steel, aluminum, copper, etc.) profiles(steel bar, angle iron, steel tees, U channel, Beams, round pipe, square tubing, etc) into round, arc, spiral, and other workpieces. Read More: Profile Bending Machine: 5 Things Before Buy, 6 Steps to Bend
Rotary Draw Bending
Rotary draw bending machines are very popular because they create aesthetically pleasing bends by using special tooling or die sets. The tooling helps maintain a constant center line radius resulting in a precise bend. Rotary draw bending machines are beneficial when making complex parts that have multiple bends.
Type 6#: Rotary Draw Bending Machine
CNC Rotary draw bending is a process used to bend tubing, bar shapes, and extrusions when the centerline radius of the bend is less than 7x the material diameter. Rotary draw bending can be completed with or without a mandrel.
When using a mandrel tube bender, a steel rod or linked ball is inserted inside the pipe while it is being bent to give the material extra support. This added support prevents the material from deforming.
Type 7#: Pipe/Tub Bending Machine
Usually the pipe bender refers to the Rotary draw bending machine, so here we will list it separately:
Rotary draw bending machine is by far the most popular machine of tube bending as it is easiest to control, more precise, repeatable, and a relatively affordable tube bending machine. A Rotary Draw Bending Machine is made up of three different tools, the Clamping Die, the Pressure Die and the Radius Die that hold and form the tube throughout the bending process. The tube is clamped to the bend die and is ‘drawn’ around the die by the machine by either hydraulic or electric methods. As the bending die rotates the tubing is held in place firmly against the rotating bend die by the pressure die.
Type 8#: Rebar Bending Machine/Compression Tube Benders
Rebar Bending Machines(Compression Bending Process) are usually used for the accuracy of bending angles, it is suitable for bending wide varieties of steel bars, TMT, reinforcement bars, etc used in construction, and are capable of bending the toughest rebars application is very extensive.
Compression Tube Benders: Compression bending machines are commonly used with heavy-wall material or material that is bent to a radius >2.5 times the OD of the tube.
Type 9#: Stretch Bending Machine
The Stretch Bending Machine (also named Strech Forming Machine, and Profile Stretch Press) can be divided into rotary type Stretch Bending Machine and double arm type Stretch Bending Machine, and various special stretch bending machines, such as special stretch forming machines for shower rooms, special forming bending machine for train roof beam, and special stretch forming machine for the elevator. More Detail: Stretch Forming Machine, 10 To 300T Bending & Forming Press
Type 10#: Induction Bending Machine/Hot Bending
The induction bending machine fixes the two ends of the steel profile, sets a good bending radius at one end, and keeps the other end at a constant speed. The steel profile is locally heated by an electromagnetic induction coil, and the bending is driven by a precision screw. The cooling medium is continuously cooled and shaped to the required bending angle. More Detail: Induction Bending Machine, Heater Bending Pipe