Omega (Hat) Profiles — Structural Hat Sections Roll-Formed to Drawing

An omega profile (hat section) 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 flat top, two webs and two outward-turned feet. The name comes from the section's resemblance to the Greek letter Ω and to a hat. The name omega is used for many profiles of different gauges and purposes; the omega we produce is a structural steel section, 1–6 mm thick, designed to carry load.

It is used as light purlins and cladding rails on roofs and walls, as module rails in solar plants, as purlins in greenhouses, as stiffeners in racking and cabin systems, and as chassis and frame members in trailers and machinery. Because it is symmetric about its vertical axis and its two feet give a wide seating face, it suits details where the connection is made through the top face and the feet. The omega rail that carries module clamps is covered on our Y Solar solar purlins and rails page.

An omega section is symmetric about its vertical axis. When the load passes through that axis the section is not forced to twist, unlike a C-section, whose shear centre lies outside the web; its top face and two feet give wide, flat connection faces. Fastened by its feet to a sheet by welding, riveting or bolting, the section becomes a closed box and its torsional stiffness rises sharply, which is why it is common as a chassis, cabin and panel stiffener.

For longer spans and higher loads a lipped C-profile is usually chosen, and along long purlin runs a Z-profile, which can be lapped over the supports, lowers tonnage. Many systems combine them: on solar tables C or Z purlins span between the beams and omega rails carry the modules.

An omega section is defined by four dimensions: height (h), top width (b), foot (f) and thickness (t). Height sets the bending capacity, top width the mounting face, the feet the bearing and connection face on the supports, and thickness the 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. A wide, flat face in compression is the part most prone to local buckling; adding a longitudinal step (stiffener) to it enlarges the effective section and on a roll-forming line usually means just one or two more stations. The project's structural calculation sets the final section; we support projects from the start with section optimisation and material and coating choice.

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

For example an omega with h × b × f = 50×60×25 mm in 2 mm weighs about 3.15 kg/m. For your own size use our steel weight calculator or send us your drawing.

No. We form omega 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 solar rails and greenhouse profiles that work outdoors. See our Zn-Al-Mg vs galvanized guide; we also supply ZM-coated sheet as raw material.

Omega profiles that will be painted or welded into a fabrication, such as trailer and machine frames, 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. Screw and bolt holes in the feet, clamp slots in the top face and splice holes are punched in the same pass as the forming, so hole positions are identical across thousands of parts and there is no drilling or aligning on site.

Profiles are cut to the lengths on your order list, then bundled and labelled by section and length. Roll forming suits multi-bend sections like the omega: an extra bend usually means just one or two more stations. Because we design and make the tooling and rolls in-house, an omega 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.