Cold Roll Forming Process,
Cold Rolling Process

For 100+ years, the cold roll forming process(aka cold rolling process, rolling metal process) has provided strong parts — quickly and cost-effectively — for numerous industries.
Roll Forming Basics: What is it? Process, Benefits, Metals Used, 7 Applications, 5 Types, Design Guide

Cold Roll Forming Basics

Roll forming video from Dalarna University:
“What exactly is Roll Forming?”
Find out the basics…watch this short instructional video produced by Dalarna University.

Cold Roll Forming Process(rolling metal process) is a kind of cold bending processing, also called profile sheet bending, is a reliable, proven approach to metal shaping, and is an efficient, effective shaping that delivers tight tolerances on complex profiles, which is ideal for modern applications.

A method of rolling relating to the continuous bending of a long strip of sheet metal (typically coiled steel) into a desired cross-section is roll forming. In the roll-forming process, permanent deformation is achieved by subjecting the material to high compressive stress by allowing the material to pass through the gap between two rotating cylindrical rolls, also spelled as roll-forming or roll forming.

The rolls may be flat or grooved and are kept at a fixed distance apart from each other. The rolls are rotated in opposite directions by means of the electrical drive system (motor, gearbox, spindle, and couplings).

Features

Cold roll forming is the process of gradually bending a flat strip or coil of metal into a longitudinal, uniform profile. the cold roll forming process uses a continuous bending operation where long metal strips, typically coiled steel, are passed through consecutive sets of rolls at room temperature. Each set of rolls performs incremental parts of the bend to produce the desired cross-section profile. Cold roll forming is a cold-forming process that doesn’t require heating up the metal. High-temperature, specialized equipment isn’t necessary to produce cold-rolled shapes.

Unlike other metal shaping methods such as plate rolling, the cold roll forming process is inherently flexible. Secondary processes can also be integrated into a single production line, other than roll formation, a variety of metalworking tasks are performed by these machines, including material cutting and roll punching. Roll-forming machines operate in a continuous cycle, for the most part. The material is fed into the system where it constantly works its way through each operation’s phases, finishing with the product completed.

Why is the roll forming process important?

The rolling process is the most important metal-forming process, more than 95% of ferrous and non-ferrous metals and alloys are processed to their usable shapes by rolling. Usable shapes of rolled metals are plate, sheet, strip, foil, and different sections like rail, beam, channel, angle, bar, rod, seamless pipe, etc.

Firstly, it allows for the efficient and cost-effective production of complex and customized metal profiles. By feeding metal coils through a series of rollers, the roll forming process gradually shapes the material into the desired profile. This eliminates the need for multiple manufacturing steps, such as cutting and welding, resulting in significant time and cost savings.
Secondly, roll forming offers exceptional precision and consistency in forming metal profiles. The use of computer-controlled machinery ensures that each component produced is of the same dimensions and specifications, reducing variations and ensuring high-quality products.
Moreover, the roll forming process is versatile, capable of working with a wide range of metals, including steel, aluminum, and copper. This flexibility makes it suitable for various industries, including automotive, construction, aerospace, and appliance manufacturing.
Additionally, roll forming enables the production of long lengths of continuous profiles, which is advantageous for applications requiring seamless and uninterrupted components. This contributes to the structural integrity and durability of the final products.

features of the roll forming process

Roll forming machines are designed to efficiently bend metal at room temperature using a series of fixed rollers. These rollers serve two purposes: they guide the metal strip through the machine and make the necessary bends. .
The strip of metal passes through each station of rollers, with each set bending the metal slightly more than the previous one. This progressive bending process ensures that the desired cross-sectional configuration is achieved while maintaining the cross-sectional area of the workpiece.
One of the advantages of roll forming is its high production speed. Roll forming machines can operate at speeds ranging from 30 to 600 feet per minute, making them ideal for producing large quantities of parts or extremely long pieces.
Additionally, roll forming machines excel in creating precise parts that often require minimal finishing work. Depending on the material being shaped, the end product typically exhibits an excellent finish and fine detail.

Overall, the roll forming process, facilitated by roll forming machines, offers efficient and precise metal bending at room temperature, making it a favorable choice for high-volume production and the creation of parts with minimal finishing requirements.

What can cold roll forming do?

Cold roll forming is a versatile process that can accomplish various tasks in the manufacturing industry. It can:

Shape complex profiles: Cold roll forming can create intricate and complex profiles with multiple bends, curves, and cutouts. It enables the production of custom-designed components tailored to specific requirements.
Produce long lengths: The process allows for the continuous production of long lengths of profiles. This is beneficial for applications that require seamless and uninterrupted components, enhancing structural integrity and reducing the need for joining or welding.
Form different materials: Cold roll forming can be used with a wide range of materials, including steel, aluminum, copper, and more. This versatility enables manufacturers to work with different metals depending on the application’s requirements.
Achieve tight tolerances: With precise control and adjustment of the roll forming machines, tight tolerances can be achieved consistently. This ensures uniform dimensions and accurate specifications for the produced components.
Offer cost-effective solutions: Cold roll forming eliminates the need for multiple manufacturing steps, such as cutting, welding, and secondary operations. This leads to cost savings in terms of labor, time, and material waste, making it a cost-effective manufacturing method.
Cater to various industries: Cold roll forming finds applications in numerous industries, including automotive, construction, aerospace, appliances, and more. Its versatility and customization capabilities make it suitable for a wide range of sectors.

Cold roll forming is a flexible process capable of shaping complex profiles, producing long lengths, working with different materials, achieving tight tolerances, providing cost-effective solutions, and serving diverse industries. Its advantages make it a valuable technique in modern manufacturing.

What are the raw materials for cold roll forming?

In cold roll forming, the raw material used can be in the form of either flat or coiled sheets. While mild steel is commonly used, it is worth noting that other ductile metals are also suitable for the process. Some traditional materials used in roll forming include:

Galvanized and Galvannealed Steel: These are steel sheets coated with a layer of zinc or zinc-iron alloy, providing corrosion resistance and enhanced durability.
Stainless Steel: Known for its excellent corrosion resistance and aesthetic appeal, stainless steel is often used in applications that require high durability and hygiene, such as food processing and medical equipment.
Aluminum: Aluminum offers lightweight properties, excellent corrosion resistance, and high conductivity. It is widely used in industries such as automotive, aerospace, and construction.
Copper: Copper is valued for its exceptional electrical conductivity and heat transfer properties. It finds applications in electrical components, plumbing systems, and architectural features.
Brass: Brass is an alloy of copper and zinc, offering a combination of good electrical conductivity, corrosion resistance, and aesthetic appeal. It is commonly used in decorative and architectural applications.
Bronze: Bronze, an alloy of copper and other elements such as tin or aluminum, possesses high strength, wear resistance, and durability. It is utilized in various industries, including marine, automotive, and sculpture.

These materials provide manufacturers with options to select the most suitable raw material for their specific application requirements, considering factors such as strength, corrosion resistance, conductivity, and aesthetics.

3 rules to keep in mind

But every so often we hear about using different source material. Here are some rules to keep in mind:

Good Ductility: It is important to avoid materials with poor ductility, as they may not be suitable for roll forming. Ductility refers to a material’s ability to deform under tensile stress without fracturing. Materials with low ductility can result in cracking or failure during the roll forming process.
Avoid Brittle Materials: Materials that are hard or brittle, such as cast metals or certain heat-treated alloys, are generally not suitable for roll forming. These materials lack the malleability required for the forming process and are prone to cracking or breaking.
Consider Heat-Treated Alloys: Certain heat-treated alloys, like the commonly used 6061-T6 aluminum, are not ideal for roll forming. Heat treatment processes can increase the hardness of the material, making it less formable and more susceptible to cracking during the roll forming process. In such cases, metal extrusion is often the preferred manufacturing method.

It is important to select source materials that are ductile, malleable, and suitable for the specific requirements of the roll forming process. Understanding the formability and properties of different materials is essential to ensure successful and reliable roll forming operations

How to choose the right material?

When choosing the right material for roll forming, it is essential to consider several factors related to the roll forming process and the desired end-use requirements:

Thickness: The thickness of the material is an important consideration. It should be suitable for the specific roll forming machine and its capabilities. The material’s thickness will impact the forming process and the achievable profile shape.
Mechanical Properties: Evaluate the mechanical properties of the material, such as yield strength, tensile strength, and elongation. These properties determine the material’s ability to withstand forming stresses and maintain structural integrity. The material should have sufficient ductility and strength for successful roll forming.
Surface Quality: The surface quality of the material is important for both aesthetic and functional reasons. Assess the material for any imperfections, such as scratches, dents, or surface contaminants, as they can affect the final appearance and performance of the formed components.
Uniform Flatness Tolerances: Consider the required flatness tolerances for the end product. Roll forming can help improve the flatness of the material, but it is essential to choose a material that can meet the desired flatness specifications.
End-Use Requirements: Understand the specific requirements and performance expectations for the roll-formed components in their intended application. Consider factors such as corrosion resistance, conductivity, thermal properties, and any other relevant criteria to ensure that the chosen material meets these requirements.

Additionally, consult material specifications, standards, and guidelines provided by industry organizations or suppliers to make an informed decision.

Overall, choosing the right material for roll forming involves evaluating factors such as thickness, mechanical properties, surface quality, uniform flatness tolerances, and end-use requirements to ensure optimal performance and successful production of the desired components.

What is cold roll forming capability?

Typical cold roll forming mills can accommodate material gauges ranging from .010″ up to 0. 250″ thick. The bend radius is largely determined by the ductility of the metal. However, 180-degree bends are commonly achieved with the right material. Roll forming easily accommodates the integration of secondary operations such as welding, punching, and precision laser cutting to optimize production efficiency.

6 factors that determine the ability of cold roll forming

Material Compatibility: The machine should be capable of handling various types of metals, such as steel, aluminum, and stainless steel, with different thicknesses and strengths. The design and specifications of the machine should allow for proper feeding, shaping, and cutting of the selected materials.
Profile Complexity: The machine’s capability is influenced by the complexity and intricacy of the profiles it can produce. A high-capability cold roll forming machine can create a wide range of profiles, from simple shapes to more intricate designs with multiple bends and contours.
Accuracy and Consistency: The machine’s capability is reflected in its ability to consistently produce profiles with precise dimensions and tolerances. Accurate roll tooling, precise alignment, and advanced control systems contribute to achieving the desired level of accuracy and consistency.
Flexibility and Adjustability: A cold roll forming machine with a high capability offers flexibility in terms of adjusting the roller positions, settings, and other parameters. This allows for quick and efficient changeovers between different profiles, minimizing downtime and maximizing productivity.
Speed and Production Efficiency: The capability of a cold roll forming machine also includes its production speed and efficiency. Higher-capacity machines can operate at faster speeds while maintaining quality, enabling increased output and shorter lead times.
Customization Options: Advanced cold roll forming machines may offer customization options, such as the ability to create profiles with specific hole patterns, embossing, or other customized features. This capability allows manufacturers to meet unique customer requirements and specifications.

Advantages

Roll forming offers numerous advantages that make it a preferred manufacturing method for a wide range of industries:

Optimal for Long Lengths and Large Quantities: Roll forming excels in producing profiles with long lengths, making it ideal for applications where continuous lengths are required. Additionally, it is a high-speed process suitable for large quantity production, ensuring efficiency and cost-effectiveness.
Consistent and Accurate Results: The use of computer-controlled machinery in roll forming ensures consistent and precise shaping of profiles. This results in uniform dimensions and tight tolerances, providing accurate and reliable products.
Suitable for a Variety of Metals: Roll forming is compatible with various metals, including steel, aluminum, copper, and more. This versatility allows manufacturers to select the most suitable material for their specific application requirements.
Environmentally Friendly: Roll forming is considered environmentally friendly due to its efficiency and minimal material waste. The process eliminates the need for excess material and reduces energy consumption, contributing to sustainability efforts.
Custom Product Design and Manufacture: Roll forming allows for custom design and manufacturing of profiles. It offers flexibility in creating complex shapes and customizing profiles to meet specific requirements, enabling manufacturers to produce unique and tailored components.
Corresponding Curvature Radius: The curvature radius in roll forming corresponds to the thickness of the metal strip, ensuring compatibility and accurate shaping of the profiles.
Weight Reduction: Roll forming enables the use of high-strength steels with high elastic limits, leading to lighter-weight structures without compromising strength and structural integrity.
Ease of Implementation in Assemblies: Roll-formed profiles can be easily integrated into assemblies using various methods such as welding, riveting, bolting, and gluing. This provides flexibility in designing and assembling components.
Variety of Delivery Lengths and Surface Conditions: Roll-formed steel profiles can be delivered in a variety of lengths, including long lengths of up to 30 meters. Additionally, there is a wide range of surface conditions available, such as hot roll, pickled, cold rolled, prepainted, and galvanized, offering options to meet specific requirements and aesthetics.

Available roll-forming materials

Cold roll forming is a versatile process that can form a wide variety of metals and materials, including:

Cold rolled steel: High material hardness, resistant to flattening and deformation. It also is abrasion and erosion resistant, offers good breaking resistance, and has high toughness.
High-strength, low-alloy steel: High-strength, low-alloy (HSLA) steels have nearly the same composition as plain carbon steels. However, they are up to twice as strong and their greater load-bearing capacity allows engineering use in lighter sections.
Steel/ Stainless Steel: contains a high percentage of chromium, which lends it high staining and corrosion resistance.
Hot rolled, pickled, and oiled steel: It has been processed to remove surface impurities. When traditional hot-rolled steel is pickled and oiled, it becomes more durable and rust-resistant.
Galvanized / Galvannealed Steel: the surface of the metal features a bonded coating of zinc-iron alloy.
Aluminum: a soft, malleable, and lightweight metal with excellent resistance to corrosion.
Brass: a copper and zinc alloy featuring a bright, gold-like color and a high resistance to corrosion.
Copper: a ductile metal noted for its electrical conductivity.
Bronze: Highly ductile, low friction.
Composites: materials engineered from two or more materials.

7 cold roll forming applications in disguise

Cold roll forming finds numerous applications where its advantages of rapid production, design accuracy, multi-bend profiles, and high-end finishes are beneficial. Here are seven cold roll forming applications:

Power Distribution Components: Cold roll-formed shapes are used in the manufacturing of power distribution components, such as electrical enclosures, switchgear, and distribution panels. The precise forming capabilities and efficient production make it suitable for producing these components.
Warehouse & Data Storage: Cold roll-formed sections are extensively used in the construction of warehouses, shelving systems, and storage racks. The ability to create custom profiles and the cost-effective nature of roll forming make it an ideal choice for such applications.
Commercial Food Storage: Cold roll-formed components are utilized in commercial food storage systems, including walk-in refrigerators and freezers. The accurate forming process ensures tight seals and structural integrity, providing optimal temperature control and storage conditions.
Solar: Cold roll forming plays a significant role in the solar industry, particularly in the production of solar panel racking systems. The versatility of roll forming allows for the creation of custom profiles that support solar panels, ensuring proper installation and maximum energy capture.
Trains: Cold roll-formed sections are employed in the manufacturing of various train components, such as window frames, door frames, interior panels, and structural elements. The ability to produce long-length sections and complex shapes makes roll forming a suitable choice for the rail industry.
Trailers & Trucks: Roll-formed sections are widely used in the fabrication of trailers and truck bodies. The process allows for the production of lightweight, yet durable components with precise shapes, enhancing the overall performance and efficiency of the vehicles.
Guard Rails & Signposts: Cold roll-formed profiles are commonly utilized in the construction of guardrails, highway barriers, and signposts. The accurate forming process ensures consistent dimensions and strength, providing reliable safety features on roadways.

These applications demonstrate the versatility and effectiveness of cold roll forming in various industries, where it offers efficient production, design flexibility, and high-quality finished products.

4 Types of Roll Forming processes

Every roll forming manufacturer uses a unique set of rolling processes to create their products. Some specialize in tubing, while others produce roofing and siding.

Roll Bending: This process is used to bend thick, large metal plates. Three or four-roll plate bending machines are utilized to roll the plate and create the desired curve. The placement of the rollers determines the bend and angle, which is controlled by the distance between the rollers.
Flat Rolling: Flat rolling is the basic form of roll forming, where the end material has a rectangular cross-section. In this process, two working rollers rotate in opposite directions. The gap between the rollers is slightly less than the thickness of the material, and the material is pushed through by the friction between the material and the rollers. This elongates the material due to the decrease in thickness. Multiple passes may be required due to the limited deformation in a single pass.
Profile Roll Forming: Profile roll forming is used to create molded sections without changing the thickness of the metal. It involves cutting different shapes in the workpiece to form sections such as irregular-shaped channels, trims, I-beams, L-beams, U-channels, and rails for railroad tracks.
Ring Rolling: In ring rolling, a small-diameter workpiece is rolled between two rollers to form a larger-diameter ring. One roller serves as the drive roller, while the other is idle. An edging roller ensures a constant width of the ring. The reduction in width is compensated for by an increase in diameter. This process is commonly used to create seamless large rings for applications such as bearings, flanges, and industrial equipment.

Each of these roll forming processes has its own specific application and advantages, allowing manufacturers to produce a wide range of products with different shapes, sizes, and functionalities.

What is a cold roll forming machine?

The cold roll forming machines make specific configurations out of long strips of metal, most commonly coiled steel. They have more group-forming rollers to control the localized processing of the material to prevent folding and wrinkling during the process, it is designed to meet the needs of metal bending. As the workpiece passes along the line, each roller further reduces its thickness by a specified percentage until the piece reaches the desired thickness.

In most applications, the cross-sectional profile is usually tailored to the specific needs of the customer for the roll forming machine to bend the metal as necessary

The two benefits of roll forming machines

Energy-efficient because roll forming machines do not expend energy to heat material—the metal shapes at room temperature
An adjustable process and applicable to projects of varying time duration so results in a precise, uniform part.

6 components of the cold roll forming machine

Infeed Section: The Infeed Section is mainly used for loading and feeding the material, which is mostly in the form of continuous cut sheets or in continuous coils depending on the final product to be processed.
Roll Forming Section: The Roll Forming Section is mainly for the processing of the incoming sheet. It contains a roll forming system with multiple rollers, as well as drives, power systems, and infrastructure. The main purpose is to continuously process the profiles that pass through the roll forming section to achieve the desired metal component.
Shearing Section: After the continuous processing of the profile, the profile is cut to the required nominal length according to the specified length.
Exit Section: After the complete processing procedure has been realized, to prevent the finished product from falling, a table is added to carry out the storage of the finished profile.
Control System: A PLC control system is used to achieve a fully automated production model and to realize processing accuracy and cutting precision.
Additional Kit: When carrying out production, there may be many additional needs, such as printing logos, straightening, embossing, etc.

Top 11 Design Guides of the Roll Forming Process

When designing for the roll forming process, consider the following guidelines for optimal results:

Select materials based on strength, formability, and cost.
Simplify profile designs to reduce costs and enhance manufacturability.
Determine appropriate wall thickness and material gauge.
Ensure bend radii and roll diameters are compatible with material properties.
Collaborate with tooling manufacturers for precise and durable tooling.
Define dimensional tolerances and communicate them clearly.
Consider straightness and flatness requirements, and plan for post-processing if needed.
Discuss hole and slot placement with roll forming experts.
Account for surface finish and coating requirements.
Conduct testing and prototyping to validate the design.
Maintain open communication and collaboration with roll forming professionals throughout the process.

Final Words

In conclusion, the Cold Roll Forming Process is a highly efficient and versatile technique that has revolutionized the manufacturing industry. Its ability to shape metal sheets into complex profiles with exceptional precision and consistency makes it a preferred choice for various applications. With advancements in technology, this process continues to evolve, offering greater customization and cost-effective solutions to meet the ever-changing demands of the market. Whether it’s in the automotive, construction, or aerospace sectors, Cold Roll Forming Process stands as a testament to the ingenuity and innovation driving the manufacturing world forward. Embracing this process opens up a world of possibilities, ensuring quality products and streamlined production processes.

Resource: MP Metal Products

Cold Roll Forming Process, Cold Rolling Process