Pretty much every company ever wants to do a job rapidly and for as little cost as possible. What good is an engineer who can’t make a design more efficient, or a purchaser who isn’t getting the best bang for her buck?
For 100+ years, roll forming has provided strong parts — quickly and cost-effectively — for numerous industries.
What Is Roll Forming?
So, what is roll forming exactly? It’s the process of gradually bending a flat strip or coil of metal into a longitudinal, uniform profile. To get the desired shape, the operator passes the workpieces through a series of mated tool dies.
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. The differences between hot and cold forming have an impact on final component properties (and will be covered further down the page).
Raw material can be either flat or coiled sheets. It’s possible to use hot rolled steel in sheet form as the raw material in cold roll forming. You just wouldn’t form it “hot off the presses,” so to speak — it would be room temperature for days by the time your roll former works with it.
There are many ways to manufacture metal components, many of which we’ll touch on further down this page. Roll forming must have a purpose and a niche, right? You bet — it’s the most economical manufacturing process for the mass production of:
- Channels (C, J, box, hat)
- Complex shapes with multiple bends
- Long components with holes
Roll forming also allows for the cost-efficient, simple addition of in-line punching features such as:
Designing these elements into custom tools eliminates the need for slow, expensive secondary operations. Roll forming lowers production costs and slashes lead times significantly — as long as the shoe fits.
Benefits of Roll Forming
Many of the perks of cold roll forming aren’t otherwise available. Certainly not all in the same package. But we’ve only scratched the surface so far.
Let’s unroll the full list of advantages of roll forming:
The nature of the roll form process allows for advanced in-line addition of punched features and embossings. Your manufacturer can eliminate multiple-stage operations, excessive scrap, and slitting burrs.
Order Volume Flexibility
One of the myths the industry faces is that its viability is very volume-dependent.
Although high volumes are certainly the most cost-effective way to utilize roll forming, small and medium runs don’t have to be a non-starter. Depending on your part design, volumes as low as 10,000 to 20,000 linear feet per year can be cost-effective.
Your manufacturer can also provide economic order quantity runs. These allow for inventory to be held by the manufacturer and distributed to you when needed. Economic runs maximize volume and reduce setup time, and you don’t run dry.
Your manufacturer may also be willing to discount small orders in exchange for a longer contract.
Complex Profiles With Intricate Bending
A roll former can go whether many other metal forming processes don’t dare. With a little clever engineering, it’s capable of producing a wide range of cross-sections.
Designs with multiple bend radii cause problems in press brake forming for a variety of reasons. Same goes for multiple-angle parts — alternative process create production delays by requiring frequent tool changes and equipment resets.
Tight, Repeatable Tolerances
As long as your manufacturer is familiar with roll form machines (and not utterly incompetent), it’ll turn out high-precision parts.
Done correctly, roll forming can hold tolerances up to +/- 0.005” on certain profile segments. Overall part lengths can be accurate up to +/- 0.020”.
Designs do need to take end flare and springback into consideration. Your manufacturer should understand how these distortions can be controlled by proper design and production setup.
You Can Make Big Things Happen
With roll forming, you can produce any length of piece you want! Remember, roll formed parts are limited in length only by how much material is on hand.
Little Tool Maintenance
Tool maintenance tends to be less for a roll formed section than for a stamped component. This is because roll formers can produce parts and features in a continuous motion.
The best way to determine scope of tool maintenance is to look at your order volume.
Capable of Forming High-Strength Metals
Not all metal manufacturing processes can handle high-strength metal. Or, if they can, it’s at the cost of rapid tool damage.
Being able to cold roll high-strength materials such as high-strength, low-alloy (HSLA) steel gives you an advantage over standard-strength materials such as 1040 carbon steel. HSLA steel is great for structural components in many industries.
Ownership of Tooling
Cost amortization allows you to maintain full ownership of your tooling and avoid hidden fees. You also get:
- Lower total cost of ownership: Amortization immediately reduces up-front manufacturing costs and gives you the ability to make small payments.
- Long-term ROI: You pay once for the tools and can keep them for other projects!
- Flexibility: Want to take your tooling elsewhere? Go for it.
Fewer Chances for Error
Roll form machines in the 21st century are beautifully efficient. Thanks to CAD software, the machines are highly automated, requiring less manpower. That means fewer chances for human error.
Speed and adaptability are key to industries with quick turnaround times.
One of roll forming’s claims to fame is that it produces less scrap waste than many other metal forming methods.
Scrap cost is typically 1-3% of your overall cost. This perk is doubly awesome when you’re working with expensive materials.
Applications for Roll Forming
Many product profiles are challenging to make through press braking, stamping, or extrusion (more on that further down this page). These same applications can be cost-efficiently made at high production rates with roll forming.
These are the criteria for specifying cold rolling:
If your project fits into a least a couple of these buckets, it may be ideal for roll form manufacturing:
- Long, slender shapes (up to 30’ long is common)
- Repeating punch patterns in a family of varied length parts all sharing the same profile
- Medium to large annual volumes. Tooling can get expensive for short runs
- Aesthetic projects where tool marks aren’t acceptable. The gradual shaping process actually eliminates tool marks!
- Complex cross-sections
- Deep U-shaped channels with narrow openings
Roll forming is ideal for many industries — some obvious, others not so much. Many of these industries have taken advantage of roll forming for decades, while others are still learning about its virtues:
Millions of miles of guard rails have gotten their sturdy, strong shape from roll forming.
Guard rails can be galvanized right at the plant. Adding that zinc layer helps the component stay resilient in all types of conditions.
Solar Panel Mounting Components
Roll formed parts make up the framing system that holds many solar panels on:
- Commercial roofs
- Utility-scale solar power farms
- Residential roofs
American roll formers take solar market projects more than any other type of job.
Most commercial buildings are built not with steel studs in the wall, but with roll formed parts.
They’re put out very quickly by companies that are very dedicated to this super-niche industry and have the required specific certifications. The architect needs to know the part can meet loading standards and requirements before he’ll even consider it.
Almost all tubing is roll formed. Tubing is rampant in manufacturing for appliances, automobiles, architecture, and more.
Tubing can be square, round, oval, and rectangular. In roll forming, all tubing is welded seamlessly thanks to scarfing.
Roll formed tubing comes in many forms of metal. Occasionally, however, aluminum tubing is done by extrusion instead.
Siding & Roofing
The entire shell of a building can be made with roll formed components.
You’ll see a lot of metal roofing on houses around the Northeast. That’s another commodity business dominated by just a few roll forming companies.
Other Structural Components
These roll formed components require a heavier gauge. Purlins or Z profiles are commonly specified for all kinds of heavy-stress structures.
Typical applications in the automotive industry include:
- Frame rails
- Door beams
- Roof bows
You can order window stiles and rails made from roll formed parts. (Stiles are vertical profiles, and rails are horizontal pieces.)
Hollow window trim reduce your costs while giving you an elegant design look. Plus, you simply install it by snapping it on!
Door frames, casings, and other parts can be created via roll formers. There are many versions of this framing available for the edges, bottom, and top of your door, depending on what type of hardware will be used. Roll forming these parts is quite common.
Higher volume “standard” doors use roll forming for door edge, top and bottom framing, which results in lower costs.
You can also use roll formed parts to add glazing. These can be either flush mounted or overlapping.
Finally, some door faces are roll formed, too. If so, this step is usually handled by the door manufacturer rather than a third party.
Elevator shaft tracking and some of the structural cab components are made by roll forming.
Roll formers can also class up an elevator. Interior decorative cab components are also roll formed
There’s a ton of roll forming at play here.
All the tubing that’s part of the refrigerant exchanger is made of roll formed copper. Plenty of structural components for the outside shell are roll formed.
In commercial food storage, this process can be used to form:
- Kick plates that keep out dust bunnies
- Stainless steel rails on the edges
- Decorative trim and cornice work for appealing displays in grocery and convenience stores
Any kind of transportation is a target for optimization via a switch to roll formed parts.
Structural chassis components are the bulk of the industry. This applies to both the auto and construction sectors. You want interior doors that protect your end user during a crash? Use roll formed parts.
On trailers and trucks, the back structural components and the chassis are roll formed. The outside shell uses decorative metal trim.
On trains, the siding can be roll formed stainless steel. This is a common route for city public transportation.
Trains also use structural and both exterior and interior decorative metal parts made through roll forming.
There’s untapped potential for decorative metal components in ships. Work and government boats, we’re looking at you.
There’s currently a lack of creativity on the stainless steel furniture inside. It’s all boxy and mundane.
Roll forming opportunities abound for cabling and power table trays. They can be hung along the length of the ship for convenience and reliability.
Cable trays, wire raceways … these have to be made out of steel. Why not roll formed steel? Those products are typically made of galvanized steel, a material roll formers can handle just fine.
Copper busbars/conductors are commonly roll formed.
Roll Forming Costs
The cost of roll formed channels can be traced back to several factors:
- Complexity of shape
- Raw material cost
- Order volume
Complexity of Shape
The complexity of the profile and the punching needed will determine if any cost is added here.
Profile height may add to tooling cost. Taller profiles need roll form tools with larger diameters, which adds to the amount of tool steel needed.
Once a roll forming line is set up, labor becomes quite inexpensive. Roll forming is a single-stage process, so there’s little human labor necessary.
Raw Material Cost
Your biggest cost with roll forming is the price of the raw material, coming in at 55-70% of the final price. The beauty of this process is that it produces so little scrap that it only comprises 1-3% of the overall cost.
Roll forming tooling costs are yet another unfortunate myth about this process.
First of all, tooling for any kind of metal fabrication can be expensive. With smart purchases, roll form tooling is no more expensive than any other type. Here are a few ways to control tooling costs:
- If your manufacturer participates in part design, it may be able to optimize the part for roll forming tooling.
- Payments can be amortized over time to avoid high up-front costs.
- Your manufacturer can discount tooling in exchange for a commitment to buy a certain number of parts over time.
- A roll former that’s been around for a long time may already have existing tooling that’ll work for your project.
The cost-competitiveness of roll bending isn’t as dependent on order volume as you’d think. Sure, high volume makes sense, but some roll formers can optimize their process for smaller orders, too.
Why It’s not as Expensive as You Think
There are plenty of cost benefits baked into the roll bending process:
1. Free Stuff In-Line
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.
2. Lower Part Cost
The amount of tooling cost you add is repaid to you in the features that are added more efficiently.
Compare that payback to a multistep job shop:
- Cutting the piece
- Taking it to a press or laser cutter
- Taking it to a brake press, where someone sets the tooling and bends your part into shape
With a roll former, those are all handled in a continuous process. Roll forming is ideal for repeatable parts and processes.
3. Lower Labor Costs
With fewer processes involved, it’s only logical that you also benefit from tremendously lower labor costs. We’re talking 6% of the total project cost, whereas it’s 15-20% at a job shop.
4. Less Waiting Around
Lead time on a per-part basis is superior. We’re talking as little as 10% of that job shop’s lead time.
5. Ability to Collaborate on Optimizing the Part
If your manufacturer offers design assistance, it may actually save you money by optimizing the part for roll form tooling and processes.
Roll Forming Vs. Competing Processes
In the right situation, your company can take advantage of roll forming to efficiently produce parts that stack up against any industry. Since every situation is one-of-a-kind, let’s look deeper into the pros and cons of roll bending vs. stamping, press braking, extrusion, casting, and forging.
Most of these competing processes are done via hot forming. The challenge is that hot forming a very specialized mill process. The use of high temperatures and molten product requires huge furnaces, which aren’t exactly in abundance. It’s a major investment to buy the machinery needed to safely manage molten steel, and to find the experienced manpower to operate the equipment.
And the Difference Is …
There are general differences in the end result of cold forming vs. hot forming:
- Run speed and quality: With hot steel, it might take 50 rolls to thin a workpiece out, while that same piece may require 100 passes with cold roll forming. But … with more rolls, you can get tighter tolerances on the piece and a higher-quality end product. This can increase costs, but it may be worth it to your customer.
- Strength: For similar grades, cold rolled metal can be stronger than hot rolled metal because of work hardening. If hot rolled sheet is specified for a part that will be roll formed, you’ll still get a little added strength. But it won’t match the strength you would have received if you started with standard cold rolled stuff.
- Structural uses: The formula of steel for I beams is different than what’s used in cold forming. It’s less ductile and harder, which makes it tougher to bend while cold.
- Size limits: Steel sheet is only hot rolled up to a certain thickness. Roll formed parts are limited in length only by the amount of material in the coil.
Roll Forming Vs. Stamping
Stamping is not ideal for low-volume projects, in part because the tooling cost of stamping is huge. Stamping can’t form long parts, and changes to the punching pattern can’t be made.
There are certain high-volume, simple-design applications that can be stamped. These include:
- Aircraft components
- Power tools
- Lock hardware
- Lawn care
Roll Forming Vs. Press Braking
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.
Where it differs is that it’s actually much better for low-volume orders than high-volume ones.
In general, press braking gives you inconsistent results. You never know when you’ll end up with scratches and other tool marks.
Applications for press braking include sheet metal components.
Roll Forming Vs. Extrusion
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.
Extruding is yet another process that’s constrained by component size limits. 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. Structural shapes are often made with hot rolling (a combination of extrusion and rolling) to achieve a good weight/strength balance.
Besides structural components, applications for extrusions include:
- Aluminum cans
- Fuel supply lines
- Injection tech
Roll Forming Vs. Casting
Casting is often fending off competition from powder metallurgy, but there are also a few occasions when it butts heads with rolling.
From an efficiency standpoint, casting isn’t good for high-volume batches. 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:
- Heavy equipment
- Casings & covers
- Camera bodies
Roll Forming Vs. Forging
The heat involved in forging results in extremely hard components. Sometimes this is a good thing; other times it’s a literal recipe for failure. 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.
So, where are forgings worth a look?
- Steering arms
- Drill bits
- Ball joints
- Axle beams
- Landing gear
Doing It In-House Vs. Outsourcing
Maybe you’ve come to the conclusion that roll forming fits well with your project’s needs. If so, what now?
There’s a decision to be made — doing it yourself vs. using a contract roll former.
Bringing roll forming processes into your business is a complicated investment. It’s more than just buying a roll forming machine you can turn on and off as needed. There are additional costs and risks that many facilities that don’t specialize in roll forming fail to understand — until it’s too late.
That’s not to say you can’t do it. Your level of success just depends on your specific operations, needs, and goals.
Your three options are:
- Buying a roll form machine online
- Having a new-equipment manufacturer design and install a turnkey custom machine
- Outsourcing to an experienced roll former
There are three factors that should influence which path you take.
1. Cost of Equipment Vs. ROI
Roll forming equipment is more than just the forming machine itself. A full line includes:
- Material handling equipment
- Loading crane
- Uncoiling system
- Pre-punch press (if your component has holes, slots, or tabs)
- Accurate feeder/control system
- Flying die cutoff accelerator with controls
- Appropriately sized cut-off press
All of these features of the line must match your forming tools, pre-punch die, and cutoff die.
The cost of a complete roll forming system can range from $200,000 to $2 million, depending on the complexity of your component family. Most in-house systems can only produce a single part profile. A typical line can produce about 1.5 million linear feet per year in a single-shift operation.
If you’re planning on purchasing your own roll form system, you best be making high volumes to achieve decent ROI.
2. Operator Skill Vs. Quality Control
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:
- The thicknesses and properties of commercial metals vary greatly
- Runs with various lots of metal require precise adjustments to produce the expected profile
- Adjustments must be made to account for springback of harder metals
- Thicker lots require more space between roll forming tools
- Unequal pressure on roll forming shafts will cause twisting and bowing
- Accounting for component stretching
- Avoiding metal crashing into dies
Can your in-house operators cover all of these bases? You’d better hope so.
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. And, if you need service contractors, they probably won’t have schedules that meet your urgent needs. That puts your supply chain and your customers at risk.
3. In-House Inventory Management Vs. Vendor Deliveries
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:
- Will there be a full-time line operator?
- High volumes require full-time teams on the line. Will your company be able to balance the cost, output, and other dependent processes of that workload?
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.
More on ROI
Trusting a third party can be scary at first. If you’re weighing whether outsourcing your manufacturing is worth it, remember that outsourcing just one part to a U.S. supplier can improve ROI.
It’s not crazy talk to suggest you could increase your shippable units by 20% to 50%? Here’s how and when that’s possible:
When to Turn to a Supplier for ROI
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. It makes sense that these specialists’ investment in …
- Factory space
… should favor them over keeping processes in-house.
Another consideration: What kinds of orders will you produce? Higher-volume, commodity items could put a death grip on your organization’s ability to increase shippable units. 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.
So, although in-house roll forming is appropriate for some companies, it’s not a cost-effective alternative for everyone. For many, a contract roll former will produce higher ROI and reduce stress levels.
If you’ve decided that you’re best passing off production to an outside roll former, it’s time to go hunting! Look for a roll form partner that offers you a comprehensive supply system. The right supply agreement will result in:
- Cost savings
- Reliability in lead times and the supply chain
- Understanding the framework of your supply system
Best of luck with your hunt! If you’re not your OEM’s final decision maker, you may encounter a skeptical boss. If your project fits at least a couple of these criteria for using roll forming, he’ll be sold:
- Your order volumes are outgrowing the ROI of your current processes.
- Your scrap waste is out of control.
- Your current process is inefficient.
- You want more control over processes and tooling.
- You want to tighten your supply chain with vendor-managed inventory.
- You want to take advantage of lean manufacturing processes.
- You want a more environmentally friendly product.
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. We’ve been at it since 1904, so we can quickly pinpoint which manufacturing process is right for you.