What is Roll Forming and the Roll Forming Process?
Roll forming is a flexible, responsive, and cost-effective alternative to extrusion, press braking, and stamping.
Well-suited for customized or standard shape production, roll forming is a simple process ideal for even the most complex shapes.
Metal Forming Steel and Metal Materials
- Cold-rolled steel
- Hot-rolled, pickled, and oiled
- Pre-painted steel
- Galvanized steel
- Titanium alloys
- Stainless steel
- High-Strength Low Alloy (HSLA)
- Martensitic grades
- Dual phase
- Ultra High Strength Steel
- TRIP Steel
Roll Forming vs Bending Process
Roll forming is the continued process for steel strips to make the required section profile in any length as we all know bending has a limited length and will be done through several steps not continuously.
Roll forming machine can make a close type section with roller efforts under proper design, but the bending machine cannot make any close pattern section.
The only advantage of the bending machine vas the last generation of roll forming Line is can produce a profile with different section drawing among lengths. For example, the 9-meter octagonal light beam can be produced by a bending machine cause the strip width and section drawing are not the same from bottom to top.
The advantage of a new generation of roll forming vs the old type is we can form different drawing sections with one roll forming line by automatic roller change the old roll forming machine just produce one specific section of the profile. So bending different sizes of sections by the same strips is not advantageous anymore compare with new roll forming machines.
For production time and energy usage with labor cost, for sure roll forming line are more economic and fast. One line of automatic roll forming can easily operate by 2 workers at normal speed (15m/min).
Roll Forming vs Press Braking
We want to explain Roll Forming and Press Brake, Then provide a comparison between roll forming and Press Brake bending processes. Roll Forming and Press Brake are Two processes with the same result. in sheet metal fabrication while you can see the bend it’s often not clear which method was used. However, roll forming and press braking are very different ways of getting the same result, and their economics are completely different too.
Press Brake Bending Process
A press brake is a machine pressing tool for bending sheet and plate material, most commonly sheet metal. It forms predetermined bends by clamping the workpiece between a matching punch and die.
Press braking, or brake forming, is a metal deformation process that aligns a piece of sheet or plate metal along an axis. This is achieved by using a machine pressing tool (press brake) to clamp the metal piece between a punch and a die set for prearranged bending.
Press braking ensures a highly precise metal bend for several types of parts. The press braking process makes a variety of shapes, some of the most common shapes being a 90° rib form, V bottom, channel, closing, double form, hat channel, offset, open hat channel, and others.
Features of press brake bending
- Press braking is efficient and cost-effective
- small volumes and with shorter part lengths
- Larger orders get expensive very quickly
- unable to handle longer parts
- brake press is normally easier to set up
- Brake press tooling is normally less expensive than roll forming or stamping
- difficult to provide value-added features like holes or punched shapes during the process
- the force of the die shaping the metal often leaves scrapes on sheet metal
Roll Forming Process
In roll forming the metal shape by stretching it through pairs of rollers that one of them supports the underside and the other on the top surface. Each pair is shaped to provide a little more deformation. Therefore, geometry is increased a little more until the last pair produces the final shape required. by Using more complex roller shapes, it’s possible to put in multiple bends.
Roll forming is a type of metal bending that involves the continuous rolling of long strips of sheet metal to bend it into a desired cross-section. The strip of sheet metal passes through a set of rolls typically mounted on two stands.
Each set of rolls performs an incremental part of the bend until the ideal profile is achieved.
Roll forming is a simple process that can produce complex shapes. It is often a cost-effective and responsive alternative for press braking and stamping.
The important thing about the roll forming process:
- Works on the continuous coil
- No limit to the length of the bend
- Bends must all be in the same direction
- Profiled lengths are cut to size after forming
- Tooling can be expensive
- The roll forming line needs to be set up by an experienced operator
- Roll forming performs best for projects that require medium to high volumes
Types of roll forming machines
- Single duty roll forming machines: Uses strategically positioned rolls to work on a specific cross-section of the profile connected to each spindle.
- Standardized rolling machines: Uses outbound supports that are easily accessible to operators. The spindle can easily be removed.
- Side-by-side machines: They accommodate multiple profiles that contain various rolling tools.
- Double-headed machines: Contains two separate sets of rolling shafts and housings.
- Rafted machines: Has housings and spindle shafts with common rolling tools mounted on them.
Roll Forming Advantages Compared To Press Braking
- The press brake is flexible and very versatile. Almost any bend can be put in, in practically any orientation.
- Metal roll forming works on long lengths of coiled material but Brake Press material must be sheet This causes it a process for higher volume production while press braking is more of a low-to-medium volume process.
- Roll forming tooling costs are higher compared to other forming services
- Roll forming allows for more in-line fabrication, medium to large runs, higher volume orders
- More gradual forming sequence, roll forming produces extremely tight tolerances, as well as an attractive finish
- The roll forming process, allows you to add tooling to create any shape, no matter how complex. Complex profiles can change easily form through the single-pass linear roll form process.
- Roll forming easily handles high volume orders and is more cost-effective at high volumes
- In addition to production efficiency, keeping part quality is critical to any customer delivery.
4 Factors to Consider When Choosing a Fabrication Method
Here are four things to consider before choosing between press braking and roll forming.
The length of your parts is essential to the fabrication method you choose.
Longer parts are best used with roll forming over press braking. This is because press braking cannot handle the manufacturing of longer parts.
Press braking material has to be split, sheeted and cut to length before it can be entered into the press brake. Long parts such as slit coil can be added directly into the roll forming line.
Metal Fabrication Design
Consider your fabrication design and the shapes you’ll need before you choose a fabrication method. Press braking and roll forming follow different processes, and each process has varying lengths of time depending on the complexity of the shapes you’re bending.
For instance, press braking can only handle a certain amount of bends, and each one requires a separate hit. But roll forming can form complex linear shapes in one pass, which reduces production time and costs.
Some fabrication processes do better with specific materials. The material you select can make the best of your fabrication process and may even save you money.
Press braking and roll forming can form lighter materials such as flat-rolled steel or high-strength low-alloy steel (HSLA). High-strength material is difficult to press brake and roll form.
Tooling costs are often the same between press braking and roll forming. The price typically depends on the type of project you are doing.
Generally, the larger the volume you use with roll forming, the less tooling costs are less expensive for each piece. If the volume is small, then press brake tooling is likely the most cost-effective option.