WHAT IS ROLL FORMING? | METAL MANUFACTURING PROCESSES

“What is roll forming?”

Even design engineers with 20+ years of experience still Google this question. Despite its efficient and industrious nature, roll forming is a niche manufacturing process known to few, and understood by fewer.

Whether you’ve been studying your options for a while, or have no idea what roll forming is, the following should give you a solid understanding of how it compares to other metal manufacturing processes.

WHAT IS ROLL FORMING?

Roll forming is a unique metal forming process that starts with a long strip of metal, usually in coil form. The roll forming machine forces the material through a series of mated tool dies -- male and female -- to achieve a uniform shape.

Each step of the operation bends the workpiece little by little until it reaches the shape you need.

If it sounds simple, it’s not. It takes a heavy dose of engineering to determine:

The order in which each bend should happen

What needs to be underbent/overbent to account for springback

Where any holes need punched so they end up in the right place on the final profile

Each pass pushes, pulls on, and turns the metal. After a machine cuts it to length, the piece goes onto a runoff table, where your roll forming manufacturer labels and packages the product.

Additional services your roll forming company may offer include protective finishes such as prepainted or galvanized steel. This can save you a secondary step in the production process.

WHY DOES ROLL FORMING STICK TO CERTAIN SHAPES & THICKNESSES?

roll forming advantages - toolingTo be formable, a part must be linear and able to maintain a set profile through the entire length (basically, a long and skinny piece). This allows for a continuous process as the strips are fed through the machine, and minimal stopping of the machines. While the process is somewhat limiting shape-wise, it makes roll forming the most economical manufacturing process for mass production of many types of components.

Your design’s thickness and shape are tied together too. Your roll forming design’s shape and thickness will depend on the functionality, sturdiness, or straightness your components require.

Each roll forming machine has its own limits based on the number of passes you need through the machine and the amount of tonnage (force) required to cut the part. Many roll forming suppliers have multiple stations set up in-house and can match the appropriate line to your needs.

ROLL FORMING MATERIALS & APPLICATIONS

Custom roll formed products come in many materials:

Carbon/mild steel

Stainless steel

Galvanized steel

Aluminum

Copper

Brass

Bronze

As such, roll forming applications are everywhere. Some of its uses might be known to you, others not so much:

Mounted solar panels

Commercial & industrial HVAC projects

Guide rails and sign posts

Construction framing

Automotive and locomotive components

Architectural design & mouldings

Much more

WHY BOTHER WITH THE ROLL FORMING PROCESS?

Like any other metal manufacturing process, roll forming has a sweet spot. The cases in which you’d choose a roll forming company typically fall into these categories:

High Volume: If you need orders of 10,000+ consistently, roll forming is for you. This is especially true if your order and design are highly repeatable, and you can’t afford a defective batch.

Feature Attractions: Do you have a metal channel design that requires intricate bends, holes, notches, knockouts, labels, stamping, or embossing -- or a combination of two or more of these? Roll forming makes these features happen in-line -- no additional station necessary!

HOW IS ROLL FORMING DIFFERENT FROM OTHER METAL MANUFACTURING PROCESSES?

There are many ways to bend and otherwise manipulate a piece of metal. These are some of the most popular:

Stamping

A stamping press uses a tool and die surface to punch out pieces of metal from a much larger sheet. The excess material all goes in the scrap bin. Stamping techniques include bending, blanking, punching, flanging, coining, and embossing.

Stamping is used solely for shorter parts. Some product makers handle stamping in-house because it can be highly automated and requires less operator skill than roll forming.

Forging vs. Roll Forming

Roll forming is a cold forming process that does not require heating the metal. Forging involves hot forming -- very hot forming.

The forge creates extremely high temperatures to extrude and roll molten steel. Hammers, rolls, and presses shape the material into its final form.

Although cold rolling can create thousands of standard and custom shapes, some structural shapes cannot be made any other way than forging.

corrugated sheet roll forming machine

roofing sheet machine manufacturers

double layer roof wall panel roll forming machine