C-Profiles and C Purlins — Roll-Formed to Drawing

A C-profile is an open section cold-formed from steel coil on a roll-forming line: the strip passes through successive roll stations until it has a web, two flanges and a lip (edge stiffener) at each flange tip. Because it is light and stiff and holds its dimensions over thousands of metres, it is used as roof and wall purlins (C purlins) in steel buildings, as load-bearing members in racking and storage systems, as purlins and secondary beams in greenhouses, and in agricultural machinery and trailer chassis.

In solar plants the same section works as a driven pile and as the purlin that carries the modules; those uses are covered on our Y Solar C-pile and solar purlins and rails pages.

The lips at the flange tips delay local buckling of the thin-walled flanges under load. At the same thickness a lipped C therefore carries more load and is stiffer in bending than an unlipped U-channel — more structure per kilo of steel. The U is the simpler geometry and the cheaper choice wherever the load allows.

A C-section's shear centre lies outside the web, so it tends to twist under load; connections and lateral restraint are detailed to account for that. For long purlin runs a Z-profile, which can be lapped over the supports, is often preferred, and where more bending capacity is needed at the same gauge, a sigma profile with its stepped web is the next step up.

Web depth (h) sets the profile's bending capacity about its major axis, flange width (b) its minor-axis stiffness and connection face, the lip (c) the flange's buckling resistance, and thickness (t) its load capacity. Steel grade is a design lever too: with S420GD or S450GD instead of S350GD the same load is carried at a thinner gauge, lowering tonnage.

Thin-walled cold-formed profiles are designed to EN 1993-1-3, where local buckling means effective rather than gross section properties are used. The project's structural calculation sets the final section. We support projects from the start with section optimisation and material and coating choice, so you do not pay for a profile heavier than it needs to be.

The weight per metre of a cold-formed C-profile comes from its centre-line developed width: developed width (mm) × thickness (mm) × 7.85 ÷ 1000 = kg/m. The bend radii shorten the developed width slightly; the table above accounts for that.

For example a 150×60×20 mm C-profile in 2.5 mm weighs about 5.76 kg/m. For your own size use our steel weight calculator or send us your drawing.

No. We form C-profiles from pre-coated coil — Zn-Al-Mg (ZM120–ZM430) or galvanized (Z275–Z600) — so the profile leaves the line coated and needs no post-galvanizing bath. Zn-Al-Mg self-heals at sheared and punched edges and lasts longer than galvanizing at the same coating mass, which matters most on heavily punched purlins and racking members. See our Zn-Al-Mg vs galvanized guide.

Profiles that will be painted or welded into a fabrication are also rolled from black steel. Where the specification calls for hot-dip galvanizing, we supply that too.

Decoiling and levelling, roll forming, in-line punching and flying cut-off to length all happen on one line. Connection holes and slots are punched in the same pass as the forming, so hole positions are identical across thousands of parts and there is no drilling or cutting on site.

Profiles are cut to the lengths on your order list, then bundled and labelled by section and length. Because we design and make the tooling and rolls in-house, a C-section to your own drawing moves quickly to first article and series production. Our article roll forming vs press braking explains when roll forming beats press braking.

Profiles are packed by section and length, strapped with steel banding and labelled; we prepare the loading plan around the profile length. We 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; delivery terms (EXW, FOB or CIF) and the lead time are agreed at quotation. Production runs under an ISO 9001 quality management system.