Short answer: Roll forming is the cold forming of steel coil, at room temperature, through a series of roll stations that shape it step by step into a C, U, Z, sigma, omega or fully custom open section. Yılmaz Sac Profil roll-forms 1–6 mm galvanized (DX51D+Z), Zn-Al-Mg (ZM) coated, S350GD–S450GD structural-grade and black steel on rolls it designs and makes in-house, with more than 2,500 tons a month of capacity; holes, slots and cut-to-length are done on the same line.
Roll forming brings the cost per metre of constant-section, high-volume profiles down sharply; in return, every section needs its own roll set. This article covers the steps on a roll forming line, which profiles are made this way, when roll forming is more economical than press braking, how tolerances are specified to EN 10162 and how to order a custom profile.
How does a roll forming line work?
A roll forming line combines every step from coil to assembly-ready profile in one flow. The strip is paid off the decoiler, levelled, punched before forming where required and fed into a series of roll stations. Each station bends the strip a little further than the one before; how the bends are distributed across the stations is set in the forming plan known as the flower pattern. At the exit a flying cut-off cuts the profile to length without stopping the line.
Because the rolls define the section, once the material's springback has been compensated in the tooling the dimensions repeat over thousands of metres. We design and make our tooling and rolls in-house, so a new section goes to first article and series production quickly. The steps on the line are summarised below.
| Step | What happens | Why it matters |
|---|---|---|
| 1. Decoiling | Coil is mounted on the decoiler and the strip fed into the line | Continuous feed; less scrap than cutting blanks from sheet |
| 2. Levelling | Coil set is taken out of the strip in the leveller | Flat strip: even forming and accurate hole positions |
| 3. In-line punching | Holes, slots and notches are punched before or after forming | Identical hole positions across the batch; no drilling on site |
| 4. Forming stations | Pairs of rolls bend the strip step by step (flower pattern) | Edge wave, twist and bow kept under control |
| 5. Flying cut-off | The profile is cut to the ordered length without stopping the line | Production to your length list; no intermediate stock or second operation |
| 6. Bundling | Profiles are bundled by section and length, strapped with steel banding and labelled | Delivered ready for shipping and site |
Which profiles are made by roll forming?
Any open profile with a constant section is a candidate for roll forming. The most common section families and their uses are in the table, and each has its own page: C-profile, Z-profile, sigma profile and omega profile. The whole family is on the open profiles page.
The same sections work as piles, purlins and module rails in solar plants; under our Y Solar brand we have supplied more than 1 GW of solar steel. That use is covered on the solar steel profiles page.
| Profile | Section features | Typical use |
|---|---|---|
| C-profile | Web, two flanges and a lip at each flange tip | Roof and wall purlins, racking, greenhouses, chassis, solar piles and purlins |
| U-channel | Web and two flanges, no lips | Light loads, secondary members, frames |
| Z-profile | Flanges facing opposite ways; laps over supports | Long runs of roof and wall purlins, solar purlins |
| Sigma profile | Stepped, stiffened web | Longer-span purlins, heavily loaded solar piles |
| Omega (hat) profile | Central channel with two side feet | Solar module rails, structural hat sections |
| Custom section | Channels, interlocks or stiffeners to your drawing | OEM products, racking uprights, facade profiles |
Which steels are roll-formed?
Our lines form 1.0–6.0 mm material: coated steel to EN 10346 (DX51D+Z galvanized, Zn-Al-Mg (ZM) coated and S350GD–S450GD structural grades with guaranteed yield strength) and black steel to EN 10025. Formed from pre-coated coil, the profile leaves the line coated and needs no post-galvanizing bath. Zn-Al-Mg self-heals at sheared and punched edges, which matters most on heavily punched purlins and racking members; see our Zn-Al-Mg vs galvanized guide.
The weight per metre of a roll-formed profile comes from the centre-line developed width of the section: developed width (mm) × thickness (mm) × 7.85 ÷ 1000 = kg/m. For example, a 150×60×20 mm lipped C in 2.5 mm, a theoretical example size, weighs about 5.76 kg/m (coating excluded). For your own section use the steel weight calculator; any size in the 1–6 mm range is rolled to drawing.
When is roll forming more economical than press braking?
The two processes have different cost structures. Roll forming carries a one-off tooling investment (the roll set) and a very low cost per metre. Press braking needs no section-specific tooling, but every part carries cutting, handling and a separate stroke for each bend, so its unit cost is higher and rises with the number of bends. Roll forming therefore wins on constant sections with many bends in long, repeating volumes; press braking wins on prototypes, low and medium quantities, heavy plate and parts whose section changes along the length.
Where tooling and rolls are designed and made in-house, tooling cost and set-up time fall, which brings down the volume at which roll forming pays off. In many projects the two work together: until the section is frozen, samples are laser cut and bent on our 1,000-ton press brake, then series production moves to the roll forming line. How to calculate the break-even length is covered in roll forming vs press braking.
| Situation | Better fit | Why |
|---|---|---|
| Constant section, thousands of metres, repeat orders | Roll forming | Tooling made once; very low cost per metre |
| Prototype, samples or a section not yet frozen | Press braking | No section-specific tooling; a drawing change is a program change |
| Many bends with lips, stiffeners or interlocks | Roll forming | An extra bend means an extra station; limited cost impact |
| Plate thicker than 6 mm | Press braking | Our roll forming lines run 1–6 mm; the press brake bends up to 25 mm |
| Section that varies along the length, or tapers | Press braking | Roll forming produces a constant section |
| Long profiles from pre-coated (galvanized, ZM) coil | Roll forming | Coating preserved; long lengths are routine |
| Hole pattern at a fixed pitch | Roll forming | Holes punched on the line in the same pass as the forming |
How are tolerances specified for roll-formed profiles?
In Europe, dimensional and shape tolerances for roll-formed sections are referenced to EN 10162 (cold rolled steel sections; technical delivery conditions, dimensional and cross-sectional tolerances). Referencing it for dimensions without an individual tolerance gives buyer and manufacturer a shared, measurable basis. Dimensions that are genuinely critical to assembly should be flagged separately on the drawing; tight tolerances on every dimension only add cost.
Roll forming's strength is repeatability: springback is compensated once in the tooling, so thousands of metres through the same rolls come out identical. Typical deviations show up along the length rather than in the section: bow, camber, twist and end flare. A well-developed flower pattern and properly set straightening stands keep them under control. On long profiles, dimensioning every hole from one end limits cumulative error. Our guide to ordering custom roll-formed profiles covers how to specify each type of tolerance.
How do you order a custom roll-formed profile?
1. Technical package: a section drawing (DXF, DWG or PDF) or dimensions, thickness, material and coating (for example S350GD+ZM), the length list, hole pattern and estimated annual volume. 2. Technical review: manufacturability, number of stations and strip width are assessed, and where useful we come back with section changes that lower cost. 3. Tooling design: the flower pattern is developed, and the roll set and punching tools are designed and made in-house. 4. First article: the first profiles are measured against the drawing; series production does not start without your approval. 5. Series production: more than 2,500 tons a month of capacity, with punching and cut-to-length on the line. Repeat orders carry no tooling time or cost.
Profiles ship across Türkiye and to Europe, the Middle East and North America by truck or container; EN 10204 3.1 mill certificates and certificates of origin are provided on request, and delivery terms (EXW, FOB or CIF) are agreed at quotation. Production runs under an ISO 9001 quality management system. Send your drawing through the quote form or to contact@yilmazsacprofil.com, and see roll forming and roll forming manufacturer in Türkiye for our capabilities.
Frequently asked questions
What is the difference between roll forming and press braking?
A press brake bends cut blanks one stroke at a time and needs no section-specific tooling, which suits prototypes, low volumes and evolving designs. Roll forming passes coil through roll stations to build the section progressively; each section needs its own roll set, but cost per metre drops sharply and long profiles come out far more consistent. Roughly: press braking up to a few hundred metres, roll forming into the thousands.
What thicknesses and steels can be roll-formed?
Yılmaz Sac Profil's roll forming lines form 1.0–6.0 mm DX51D+Z galvanized, Zn-Al-Mg (ZM) coated, S350GD–S450GD structural-grade and black steel. Coated steels are supplied to EN 10346 and black steel to EN 10025. Parts thicker than 6 mm are bent on the press brake, up to 25 mm.
Does a new profile need tooling, and is there a minimum order?
Yes, every new section needs its own roll set; we design and make the rolls in-house, and repeat orders carry no tooling cost. There is no hard minimum on catalogue sections. A new section needs a worthwhile volume; tell us your annual metres and we will work out where the tooling pays for itself.
Do roll-formed profiles need galvanizing afterwards?
No. Profiles are formed from pre-coated coil (Zn-Al-Mg ZM120–ZM430 or galvanized Z275–Z600) and leave the line coated. Profiles to be painted or welded into a fabrication are rolled from black steel; where the specification calls for hot-dip galvanizing we supply that too.
Which standard covers roll-formed profile tolerances?
In Europe, dimensional and shape tolerances for roll-formed sections are referenced to EN 10162. Dimensions without an individual tolerance are assessed against the standard; if you flag the dimensions critical to assembly on the drawing, the quotation states the tolerance we commit to on each.
Do you export, and which documents do you provide?
Yes. We ship from Türkiye to Europe, the Middle East and North America by truck or container. EN 10204 3.1 mill certificates and certificates of origin are provided on request; delivery terms (EXW, FOB, CIF) are agreed at quotation.