About Roll Forming
Roll forming is a metal forming process used to create shapes of uniform cross section. In this process, metal in sheet, strip, or coiled form is fed between successive pairs of rolls that progressively bend and form it until the desired shape and cross section is obtained. The roll forming process adds strength and rigidity to lightweight materials (such as aluminium brass, copper and zinc), composites, some heavier ferrous metals, and specialized alloys and other exotic metals.
Stock can be roll formed into many standard shapes. These shapes are usually more economical as the roll forming tooling has already been created. Standard roll formed shapes include angles, struts, C-channel, U-channel, T-shapes, hat sections, round Z-shapes and many others.
In addition, secondary operations can also be performed on the same manufacturing line. This includes punching, piercing, notching, welding, embossing, lancing, louvering, slitting, bending, cutting, bundling and labelling.
Commercial Roll manufactures customized roll formed products. We work with you to determine the best size, shape, thickness and materials for your given application.
Roll Forming Benefits
Roll forming cross-section offers closer tolerances than all other competing sheet metal processes (brake forming and stamping).
Repeatability is inherent in the process and there are less rejection problems due to "standard" tolerances build up.
Thinner when needed
Roll formed shapes can be developed with thinner walls compared to other competing processes (extrusion).
Superior surface finish
Ideal for decorative stainless steel parts, or for parts requiring a finish such as anodizing, pre-painted and galvanized.
Up to 100 fpm (feet per min) makes roll forming a preferred process for high volume production.
Virtually unlimited lengths of a part can be run through the same set of tools.
Can utilize any bendable material, and do so efficiently. For example, up to 98% of strip/sheet material can be used in the final product, verses 67% in stamping, thus significantly reducing scrap.
Less secondary operations (Low labour cost)
Roll forming is often implemented as a cost cutting measure because secondary, and often labour intensive operations can be done in-line. This includes punching, piercing, notching, embossing, lancing, louvering, slitting, bending, cutting, bundling and labelling.
When to Choose Roll Forming
There are two main considerations in choosing roll forming as the desired process: manufacturability and economics.
The first consideration is if the product is suitable for roll forming. This includes:
- Profile Geometry
To have a good part, tools should have direct access to the bends. In case of blind corners, dimensions cannot be controlled accurately.
- Bend Radii
Because of spring-back, products with very large radii are difficult to roll form.
- Cross Section Depth
Deep (tall) sections are hard to roll form. There is high degree of residual stress build up which causes many geometric defects.
Roll forming tolerances must match your capability requirements.
The material must be bendable.
If the product can be roll-formed, then the next question is cost. Considerations include:
Roll forming is more suitable for medium to high volume needs. Minimum quantities include volumes of 45,000 per year; however, other volumes can be discussed to meet customer needs.
- Engineering cost
Tooling complexity and size can add significant up front costs.
- Tooling cost
Tooling costs are relatively high. Normally, the customer pays for tooling, and the roll former is responsible for maintenance costs.
- Material cost
Normally, comprises 75% to 80% of total product cost.
- Set-up cost
Set-up time is usually between 6 to 8 hours and requires the presence of a set up operator and a helper. Consequently, it is more economical to have larger runs (minimum volume of 8,000 ft per run).
Roll Formable Materials
Any bendable material in strip form can be roll formed. At Commercial Roll we process a variety of materials:
Ferrous, such as carbon steel, stainless steel, HSLA.
Nonferrous, such as aluminium, copper, and brass.
Coated, such as galvanized steel, pre painted, plated, anodized, etc.
|Thickness ||.010” to .180”|
|Width: ||1/8” to 20”|
|Length: ||40’ or longer|
In addition, different types of materials can be roll formed together, producing a
Copper and galvanized material roll formed together
Tolerances are affected by material, line speed, tool quality, operator skill,
measuring system and length. Typical ranges at Commercial Roll are:
|Length and pre-punched features location: || +/- .015” to +/-.100”|
|Cross-sectional: || +/- .005” to +/-.030” |
|Sweep: || +/- .100” in 10 ft |
|Bow: || +/- .100” in 10 ft|
|Twist: || +/- 3 degree in 10 ft|
Roll Forming Lines
Commercial Roll has the latest equipment and machinery available to serve our clients’ needs.
Most of the mills have a cut-off press, equipped with closed loop servo die accelerator system.
Roll form mills have rotary encoder with laser sensors, and all pre-punch presses have servo feeders.
This eliminates collision between material and die and reduces variation in length and
location of pre-punched features. All the components work under one controller unit for higher
accuracy. Shaft sizes vary from 1 ¼” to 3”, and number of stand per line: 16 to 24.
Commercial Roll utilizes different types of mills like outboard, inboard and double head roll
formers, depending on product manufacturing needs.
Roll Forming Tooling
To best serve our clients, Commercial Roll designs and manufactures all our tooling in-house. This enables us to respond quickly to quality concerns and product changes.
Our tool room has 5 full time tool makers and is equipped with necessary machinery. Here are a few examples of tooling manufactured at Commercial Roll.
Post-Punch/ Cut-off Dies
Commercial Roll takes advantage of the latest 3D CAD/CAM software to design tooling and perform manufacturing analysis, in order to maximize quality and improve cost effectiveness. (SolidWorks®, AutoCad®, Profil®)
Contact Us to Discuss Your Needs
Commercial Roll is a well-established company with a reputation for manufacturing top quality roll-formed products that meet our clients’ specific and unique needs. Learn more about our Other Services, our commitment to Quality, then Contact us today to discuss your needs!