With enough pressure and a little patience, steel can be molded like clay… up to a point. Steel members are often shaped through a process called roll-forming. No hammer, anvil, or blazing fire needed.
Roll-formed steel goes through a continuous bending operation, running a strip of metal through tandem sets of rollers that squeeze or otherwise shape the metal between them. Most of the time the steel is shaped at room temperature, sometimes called cold roll forming. For producing long lengths of metal or large quantities of members, roll forming is the process of choice.
Benefits of roll forming
Roll forming is fast and accurate, applicable to projects of varying durations. Parts are quickly produced and delivered as soon as you need them.
Roll formed steel as a building material, particularly cold rolled steel, has one of the best strength to weight ratios. In fact, cold rolled steel supports more weight than the equivalent amount of hot rolled steel. It significantly outperforms other types of building materials.
Roll forming allows the manufacturer to handle any size project because the process is so adaptable and speedy. Roll forming has a high productivity rate compared to other manufacturing processes and can be combined with other manufacturing operations in-line with the roll forming equipment.
You can produce parts of multiple lengths from the same tooling as easily as you can roll large quantities or long lengths. If consistent cross-section profiles are critical, across production lots or between individual pieces, roll forming is the way to go. The resulting pieces are finely detailed and have an excellent finish, perfect for pre-painting, pre-coating, or pre-plating.
The roll forming process is customizable so that you can produce parts with uneven legs or complex hole configurations, or parts with different lengths from the same roll sets. Virtually any supplemental operation from drilling to cutting-to-length can be eliminated through using the roll forming process.
Last but not least, roll forming is an energy saving process because the material does not require heating.
Metals used in roll forming
You can roll-form any metal that can be sheet-formed. An abbreviated list includes:
- Galvalume (R)
- Stainless steel
- Titanium alloys
If needed, two separate sections or materials can be cold formed together in a single operation to produce a composite part that loses none of the strength of the original materials.
Material for roll forming can be light gauge up to 3/6” thick and up to 30” wide. Quickly developed tools help shape it for any design.
Roll forming machine operation
As mentioned previously, tandem sets of horizontal rollers shape the metal along its linear axis until you get the cross-section profile you need. These are rollers placed in stations that progressively shape the steel as it runs through each set, instead of banging on it like a blacksmith.
The steel is fed into the roll forming machine where it continuously moves through each stage until the final product is complete. The process can roll form, cut, and roll-punch the material during the same set of operations. Bending is achieved through multiple stations of fixed rollers that guide and gradually bend the metal into the proper shape.
Roll forming ensures you get the correct cross-sectional configuration while maintaining the cross-sectional area of the piece.
By the way, all this happens at speeds from 30 to 600 feet per minute.
Machine line production
A roll forming machine can be broken down into four main parts:
- Entry section
- Station rollers
- Cut-off press
- Exit station
The material is loaded at the entry section, typically in sheet or continuous coil form. It moves along to the station rollers where forming and other operations take place. The rollers are the main driving force of the roll forming machine.
The cut-off press cuts (obviously) the metal into predetermined lengths. Usually, a flying die cut-off technique is employed due to the machine's speed and continuous operation. At the exit station, the finished part comes out onto a conveyor or table where it is manually removed.
These days, roll forming machines can be paired up with computer-aided tooling designs. CAD/CAM systems are incorporated into roll forming allowing the machine and the material to be used to their highest potential. “Smart” roller forming equipment can identify product imperfections while minimizing waste and damage.
Programmable logic controllers assure accuracy, especially for parts with multiple holes or to be cut to specific lengths. Now, roll forming machines have tighter tolerances than ever before.
A few roll forming machines even have TIG or laser welding on board. These extras make the process less energy efficient by makes up for that by removing an entire step from the manufacturing process.
Roll forming services
Roll forming is used for a variety of services and design operations. A roll forming machine can perform the following:
- Bi-metal roll forming
- Lock seams
- Marking and labeling
- Ring formation
- Pre-notching and pre-notch processes
The addition of TIG and laser welders add welding onto the list.
Roll formed steel is a cost effective material for engineering and manufacturing precision parts and tools rapidly and accurately. The roll forming process is flexible and adaptable to a wide range of design needs and produces large quantities of parts that are virtually identical.
Alternatively, roll forming can produce pieces of differing lengths from the same production line.
The integration of computer-aided design tools has made the roll forming operation even more accurate, with tight tolerances. Two metals can be rolled into a composite with this process as well.
You end up with a strong, durable piece that meets your metal design and your tolerance standards. At the very least, all parts will meet the Standard Tolerance Guide for cross-section and length tolerance, twist tolerance, and end-flare tolerance.
Roll formed steel produces tools and parts that are inexpensively manufactured and quickly delivered right to your jobsite. When precision quality is critical, ask for roll-formed steel.