How does roll forming work

In most applications, the required cross-section profile of the piece is specifically designed for the machine to bend the metal as necessary.

Other than roll forming, these machines perform a number of metalworking duties, including material cutting and roll punching. Roll forming machines, for the most part, work in a continuous cycle. The material is fed into the machine where it continuously makes its way through the stages of each operation, ending with the completion of a final product. A roll forming machine bends metal at room temperature using a number of stations where fixed rollers both guide the metal and make the necessary bends.

As the strip of metal travels through the roll forming machine, each set of rollers bend the metal a little more than the previous station of rollers. This progressive method of bending metal ensures that the correct cross-sectional configuration is achieved, while maintaining the cross-sectional area of the work piece. Typically operating at speeds between 30 to feet per minute, roll forming machines are a good choice for manufacturing large quantities of parts or very long pieces.

Roll forming machines are also good for creating precise parts that require very little, if any, finishing work. In most cases, depending upon the material being shaped, the end product features an excellent finish and very fine detail. The basic roll forming machine has a line that can be separated into four major parts.

The first part is the entry section, where the material is loaded. Shape rolling cuts different shapes in the workpiece and does not involve any change in the thickness of the metal. It produces molded sections such as irregular shaped channels and trim.

Shapes formed include I-beams, L-beams, U channels, and rails for railroad tracks. In ring rolling, a ring of small diameter workpiece is rolled between two rollers to form a ring of larger diameter.

One roller is the drive roller, while the other roller is idle. An edging roller ensures that the metal will have a constant width. The reduction in width of the ring is compensated for by the diameter of the ring. The process is used to create seamless large rings. Plate rolling machines roll sheets of metal into tightly shaped cylinders. The two different varieties of this type of equipment are four roller and three roller.

With the four roller version, there is a top roller, pinch roller, and side rollers. The three roller version has all three rollers producing pressure with two on the top and one on the bottom. The diagram below is a four roller systems forming a cylinder. There are several varieties of machines used to roll metals. The type depends on the number of spindles that are used. The spindles of the machine are mounted on a base plate that is a base table for the rolling process.

Once the rollers are mounted, they are aligned with the spindles, the rotation of which shapes the metal. Spacers hold the rolls in position and allow the spindles to easily act on the metal sheets. Every manufacturer has their own version of a roll forming machine. Listed below are descriptions of a few common versions. Stud and track machines produce assembly frames for strong, lightweight partitions, which can be up to 32 feet with varying thicknesses.

Angle roll forming machines use high tensile strength steel for form equilateral or unequal perpendicular angles, the most basic of the rolled formed profiles.

Framing is the primary use of roll formed angles, but they can also be used for rails, posts, supports, and brackets. Beam roll forming is used to produce box beams for construction. The designs produce fluted beam profiles for floor decking and framing. Beams are made from high tensile strength steel with double thickness flanges and single thickness webbing for additional strength. The primary use for seamless roll forming is the manufacturing of tubing, which can be square, round, oval, or rectangular.

The TIG process is used at the end of the roll forming process to weld the rolled tubing together as can be seen in the diagram. As with many parts from roll forming, tubing is made from a wide variety of ferrous and non-ferrous metals. Wrap roll forming machines form a wrapped L-shaped edge or flange on sheet metal. Wrap machines are very similar to a long dinner table with a set of rollers running the length of the table.

They can reach speeds of fifty feet per minute to create either complex or simple flanges. Roll forming has become the first choice for the manufacture of metal related products due to the high quality, exacting tolerances, rapid production, dimensional accuracy, and lower cost.

All metal based industries use roll forming from building construction to aircraft manufacturing. Below is a short list of the applications and products produced by roll forming. The items listed above are only a few of the wide variety of items we use every day that are rolled formed.

Others include desk drawer slides, steel support framing, metal tubing, construction flashing, roofing materials, house and building siding, and exteriors of aircraft and automobiles to name a few. Rolled steel channels are categorized by their shape, with "C" and "U" shapes being the most common.

The construction of steel channels has a wide web with two flanges to form the "C" or "U". For C channel steel with parallel flanges, UPE dimensions are used. UPN is for U shaped steel channels with tapered flanges. Three types of coatings are available for steel channels. Since steel rusts, coatings are a necessity and consist of hot dipped galvanization, zinc, or primer. The type of coating has to be chosen to meet the demands of the application where the channeling will be installed.

Technical Advances in Roll Forming. A wire brush is an abrasive tool that has stiff bristles made from a variety of rigid materials designed to clean and prepare metal surfaces.

The filaments of wire brushes are small diameter pieces of inflexible material that are closely spaced Contract manufacturing is a business model in which a company hires a contract manufacturer to produce its products or components of its products.

It is a strategic action widely adopted by companies to save extensive resources and With smart purchases, roll form tooling is no more expensive than any other type. Here are a few ways to control tooling costs:. Sure, high volume makes sense, but some roll formers can optimize their process for smaller orders, too.

There are plenty of cost benefits baked into the roll bending process:. After you buy punch tooling, you effectively get the holes put in the part for free. The shape has to be formed anyway, and the punching process is connected and continuous. Unlike other metal fabricating, where adding any feature is a recurring and cumulative cost, roll form cost is based on machine run time — no matter how many features you tack on.

The amount of tooling cost you add is repaid to you in the features that are added more efficiently. With a roll former, those are all handled in a continuous process. Roll forming is ideal for repeatable parts and processes. Lead time on a per-part basis is superior. If your manufacturer offers design assistance, it may actually save you money by optimizing the part for roll form tooling and processes.

In the right situation, your company can take advantage of roll forming to efficiently produce parts that stack up against any industry.

Most of these competing processes are done via hot forming. The challenge is that hot forming a very specialized mill process. There are general differences in the end result of cold forming vs. Stamping is not ideal for low-volume projects, in part because the tooling cost of stamping is huge. There are certain high-volume, simple-design applications that can be stamped.

These include:. Press braking suffers from some of the same deficiencies as stamping, and then some. Press braking is also ill-suited for longer components. Nor does it excel at complex bends, angles, and radii. In general, press braking gives you inconsistent results.

Applications for press braking include sheet metal components. Now things get a little more interesting. Extruding is a little more competitive with roll forming than our first two contestants. First, the bad. For a high-volume run, extrusion equipment and tooling can be very costly. Everything requires secondary processing, and there are no value-added activities that can be done in-line.

Part length has to be kept in mind; thin components are a challenge , too. Still, there is no shortage of applications where extrusions are preferable to roll formed components — especially when working with aluminum.

Besides structural components, applications for extrusions include:. Casting is often fending off competition from powder metallurgy, but there are also a few occasions when it butts heads with rolling. From a quality standpoint, it produces parts with high porosity — which, depending on your application, could be a big no-no.

Here are the applications where casting does become viable:. The heat involved in forging results in extremely hard components. High hardness is great for parts that need to resist denting and scratching. But with hardness comes brittleness — high-hardness components have low impact resistance, making them a danger for some transportation projects.

If so, what now? Bringing roll forming processes into your business is a complicated investment. Your level of success just depends on your specific operations, needs, and goals. There are three factors that should influence which path you take. Roll forming equipment is more than just the forming machine itself. A full line includes:. All of these features of the line must match your forming tools, pre-punch die, and cutoff die.

Most in-house systems can only produce a single part profile. A typical line can produce about 1. Unlike press brake machinery, roll forming lines require operators with years of experience to ensure high-quality outputs. Here are only a few of the considerations for each line:. Can your in-house operators cover all of these bases? Experienced roll forming manufacturers are guaranteed to understand and account for these variables. They know how to fully utilize their equipment.

Seasoned operators can run multiple profiles and metals on a single line. Experts are very expensive to hire full-time for your own operations. That puts your supply chain and your customers at risk.

Control over inventory is a major reason companies bring roll form projects in-house. But how does inventory control stack up against the cost of operating a roll former? Ask yourself:. Third-party roll form manufacturers already have balanced systems to provide full-time roll capabilities at a manageable cost. They can also manage inventory for you — whether that means JIT just-in-time delivery or high-stock, as-needed deliveries.

To keep inventory costs from sneaking up on you, minimize stock while providing a buffer for changes in demand. Inexperienced inventory management can cause costly supply chain snags. Trusting a third party can be scary at first. Almost all suppliers have equipment and processes designed to provide customized features inherent to the uniqueness of their product.

Whether these features contribute to a unique function or offer customers additional options, they form the core differentiation that supports their existence. Another consideration: What kinds of orders will you produce? If capacity on the line is being constricted by even one higher-volume component , outsourcing this part can exponentially increase your profitability. Profitability is about accelerating the rate of shippable units using the same costs and existing investments.

Experienced third-party suppliers are born for that. For many, a contract roll former will produce higher ROI and reduce stress levels. Look for a roll form partner that offers you a comprehensive supply system. The right supply agreement will result in:. Best of luck with your hunt! Hopefully this resource has established a case for roll forming in component manufacturing.

If you want to better understand the process, or have specific design questions, get in touch with us today. Why Roll Forming? Table of Contents. What Is Roll Forming? Benefits Applications Costs. Roll Forming Vs. Competing Processes 6.