Glossary

Rollforming Glossary

Rollforming is a versatile process used to shape metal into desired profiles, playing an important role in manufacturing industries ranging from construction to automotive. To navigate the complexities of rollforming, understanding its terminology is essential.

This glossary provides clear and concise definitions of key terms associated with rollforming, including the machinery, techniques, and components involved. Whether you're new to rollforming or a seasoned professional, this resource is designed to help you grasp the language of the process, ensuring better communication, improved efficiency, and a deeper understanding of this important manufacturing method.

Breakdown Pass

In cold roll forming, the "breakdown pass" is the first stage where the sheet metal strip begins its transformation toward the final profile.

Coil

A roll of flat-rolled metal, such as steel or aluminum, is wound into a continuous strip and serves as the raw material for rollforming. These coils are available in different widths and thicknesses, tailored to meet the specifications of the final product. Coils are the most efficient way to transport or store sheet metal.

Coil Winder

The coil winder is a machine designed to rotate or flip the coil during forming. This functionality is crucial when the coil must be processed from various angles or when specific surface treatments are required.

Controller

A manual or computer-operated device that governs the machine's operations, ensuring it functions according to specified input measurements and preferences.

Cover Printing / Cladding

At MP Metals we have the capability to clad your parts with a made-to-fit sleeve from a variety of materials and inkjet them with part numbers, descriptions or other information inline. Materials include vinyl, plastic, etc.

Drive rollers

These metal or polyurethane components propel the metal through the rollforming machine, as opposed to forming rollers which are responsible for bending the material into the desired profile and are usually free spinning.

Embossing

Embossing is a metalworking process for producing raised or sunken designs or relief in sheet metal. This process involves creating patterns or textures on the metal strip, serving either decorative purposes or functional needs based on the specifications. Wood grain and non-slip patterns are an example. Embossing can also increase the strength and rigidity of thinner gauge metal.

Finish Pass

The final pass of the set of roll tools that is made to the final product.

Flower Pattern / Profile Flower

The profile flower is a visual diagram that depicts the progression of the metal strip as it passes through each roll stage. It highlights the transformations occurring at each step and aids in analyzing and optimizing the forming process. This representation is helpful in determining the required number of passes and the degree of forming achieved in each pass.

Form Angle

The angle method that is used during the roll tooling design process to determine the number of forming passes needed and the point where the roll designer decides on the amount of forming for each pass.

Forming Rollers and Forming Stations / Roll Stages

Forming rollers are the rotating tools within a forming station or roll stage. A series of consecutive stations make up the rollforming machine, which gradually shapes the metal strip into the intended profile. The rollforming process is segmented into multiple roll stages, with each stage contributing to the progressive shaping of the metal strip. This step-by-step approach ensures that the profile is formed accurately and uniformly.

Hemming

A process in which the material is folded back onto itself to create a “hem”, similar to how fabric is sewn.

Labeling

Labeling may be necessary to add important information to the final product. Industrial inkjet printers can print lot numbers, sizes and dimensions, logos, dates, etc., on to moving rollformed parts as an inline process.

In line operations

Additional manufacturing processes integrated directly into the production line of a rollforming machine. These operations are performed simultaneously with the rollforming process, eliminating the need for separate, offline steps. Common in-line operations include punching, notching, cutting, embossing, welding, labeling, coating, cladding, and hemming. By incorporating these tasks into the production line, MP Metals can improve efficiency and streamline the overall process.

Lift Angle

The degree of bending applied during each pass of the roll tooling.

Miter

In roll forming, a "miter" refers to the angle between adjacent sides of a profile, often used to create angled or corner connections in assembled components, which can be achieved by precision sawing or cutting at the end of the roll forming process. A miter is commonly 45° so two parts can form a 90° angle when joined.

Notching

Notches are cut from the edge of the part, as opposed to punching holes in from the edges. Typically used for mechanical fastening, welding, or alignment during later assembly or can be used for aesthetic purposes, depending on the application. In rollforming, notching is often an in-line operation, meaning it occurs as part of the continuous production flow. This integration helps optimize production efficiency and maintain consistent precision.

Over Bend Pass

Overbending may be done at a roll stand that bends the part past the angle specified in the design, but takes into account the amount of spring back that will occur.

Portable rollforming machine

This machine offers all the functionality of a traditional metal rollformer but is designed in a compact size for easy transportation, often mounted on the back of a truck or van. They can be powered by either gas or electricity and are often equipped with a built-in or stand-alone decoiler to handle the metal. Additionally, they usually include run-out tables for the finished profiles. Often used for roofing panels, soffits and gutters.

Press Braking

A fabrication method of bending sheet metal or heavier gauge metal using a machine called a press brake. It is not a typical rollforming procedure but can be utilized for specific jobs.

Profile

The cross-sectional form of a metal component produced through the roll-forming process.

Profile Geometry

This refers to the precise shape and measurements of the final profile produced by the rollforming process.

Punching

In-line punching, or pre-punching, involves creating holes, notches, or tabs on the flat sheet metal before it's shaped, often done to avoid secondary operations and ensure precision. It can serve functional purposes, such as fastening or assembly, or decorative purposes to enhance the design. However, proximity to a bend can distort punched holes and should be avoided.

Roll Gap

The roll gap refers to the distance between the top and bottom rolls (or upper and lower rollers) within a roll stand through which the metal strip passes. Precise adjustment of the roll gap is essential to ensure the accurate shaping of the profile and to avoid defects in the finished product.

Roll Stands

The components of a rollforming machine designed to house the forming rollers while managing their position and pressure. Proper adjustment of roll stands is vital to achieving high-quality end products. They ensure the metal strip is uniformly and smoothly guided through the rollers.

Roll Stops or Traps

Also referred to as the side roll or edge guide, its function is to securely hold the flat stock in place during each individual pass, ensuring the material remains properly aligned and does not deviate from the intended path through the rollers. This alignment is crucial for achieving precision and consistency in the forming process.

Rollers

Cylindrical tools part a roll-forming machine, designed to bend and shape metal as it progresses through each roll station. These rollers are engineered to create precise, incremental bends, ultimately achieving the desired metal profile with accuracy and consistency.

Roller Conveyor

The roller conveyor is the roadbed of the transport system that moves the metal strip through the stations of the rollforming machine.

Run-out table

The platform used to support and keep panels or wide coil parts level as they leave the rollforming stations.

Secondary operations:

Procedures done to the products after they have emerged from the roll forming process. These can include separate press braking, welding, punching, stamping and notching.

Shear or Guillotine

A tool used to cut metal parts or components to a specified length.

Excenter Shear

This cutting tool, often paired with rollforming machines, utilizes an eccentric motion to deliver precise cuts while briefly halting the material.

Flying Shear

Designed for rollforming processes, it cuts metal strips to the desired length while moving along at the same speed as the material.

Pre-Cut Shear

The metal strip is cut at the machine's entry point before proceeding through the forming stations.

Post-Cut Shear

The metal part is first formed in the forming stations and then cut to length.

Side Guidance

Side guides ensures precise positioning of the metal strip along the rollforming machine, keeping it stable and aligned throughout the process.

Slitting

Cutting a sheet of metal into narrower strips usually in the same direction that the rollforming machines moves the material.

Step-Off Alignment

Roll tools designed to use spacers of varying lengths, reducing the width of the tools and thus reducing the amount of tool steel required.

Straight Roll Alignment

Roll tooling where the first pass matches the width of the last pass, with all inboard spacers having uniform lengths.

Stamping

A manufacturing process used to shape or cut metal by applying force with a press or die. It involves various techniques such as punching, blanking, bending, embossing, and coining to create specific shapes or patterns in the metal. In rollforming, it can be an inline, pre-cut or post-cut process.

Straightener / Straightening Unit

A device that corrects distortions in the metal strip before rollforming, ensuring straightness—especially important for forming coiled material.

Strip Width and Thickness

Refers to the dimensions of the coil strip being fed into the rollforming machine. Both parameters affect machine configuration and the quality of the final product. Proper adjustments are critical for precision shaping, machine configuration, and avoiding production errors.

Tapering

The process of narrowing a panel at one end.

Uncoiler

A device that feeds or unwinds coil material into the rollforming machine, ensuring smooth production flow.

Welding

Welding can be an inline or post-cut process. It is often used for sealing the edges of a rollformed tube, but can be used in many more applications.

Welding, TIG

TIG refers to Tungsten Inert Gas welding which uses a tungsten electrode and is known for producing high-quality, detailed welds often used for thin material like stainless-steel or aluminum. It is more clean and precise but is slower than MIG welding.

Welding, MIG

MIG refers to Metal Inert Gas welding which uses a continuous fed metal wire that functions as both the electrode and filler metal. Better suited for thicker metal welding, it is generally faster than TIG welding but can produce more spatter.

Yield Strength

The maximum stress a material can endure without permanent deformation. Crucial for material selection, it determines the right thickness and roller configuration needed for production.