Channel materials

• Stainless steel channels – 304/304L, 316/316L and other grades, for corrosive, hygienic and architectural structures.
• MS channels – mild steel ISMC, ISJC and ISLC to IS 2062 E250 and E350, and ASTM and EN equivalents.

Types of channels

ISMC (Indian Standard Medium Channel) is the most common mild steel channel in India, with tapered inner flanges. ISJC (junior) and ISLC (light) channels are lighter sections for less heavily loaded members. Parallel flange channels (PFC) to EN 10365 have flanges of constant thickness, which simplifies bolting. C channels and U channels in stainless steel are hot rolled, laser fused or press-brake bent from sheet and plate; bent channels have an inside radius at the corners and are used for lighter sections and non-standard sizes. Channels are described by depth, flange width and thickness – for example ISMC 100 or 100 × 50 × 5 mm.

Standards and sizes

Mild steel grades

Yield strength reduces for thicker sections as given in each standard. The sub-grade letter in IS 2062 and EN 10025 indicates impact testing (for example BR or J2), which matters for structures in cold climates or under dynamic loads.

Using channels in structures

Channels are strong in bending about their main axis but, because the section is not symmetrical, a load applied through the web can twist them. Designers place loads through the shear centre or brace the channel, or use two channels back to back to form a symmetrical member. Channels are widely used as purlins, girts, bracing and edge members, as stringers for stairs, and in equipment skids where the flat back sits on the base plate.

Fabrication

Channels are cut, drilled or punched, and welded or bolted. Mild steel channels weld easily and are painted or galvanised after fabrication. Stainless channels are welded with matching filler and pickled and passivated after welding; separate tools and storage prevent iron contamination.

Applications

Channels are used for building frames, purlins and girts, industrial sheds, equipment skids and bases, crane rail supports, vehicle and trailer chassis, conveyor frames, cable trays, pipe racks, machinery frames, and stainless structures in food, pharmaceutical and chemical plants. Related sections are on our angles, beams and flats pages, and all products on the products page.

Weight, handling and storage

Channels are sold by weight or by length. Theoretical weight per metre is calculated from the cross-section and the density – 7.85 g/cm³ for mild steel and about 7.9–8.0 g/cm³ for stainless steel – and can be checked with our weight calculator. Actual weights vary with rolling tolerances, so invoiced weights are based on the weighed or calculated figures agreed with the order. Bundles are sized for safe handling by crane or forklift.

Store structural sections off the ground on timber bearers, under cover where possible, and keep stainless steel apart from mild steel to avoid contamination and rust staining. Galvanised sections should be stacked with spacers so that rainwater can drain, preventing white rust.

Galvanising and coatings

Mild steel channels for outdoor sheds, purlins, cable trays and vehicle bodies are hot-dip galvanised or painted. Cold-formed galvanised C and Z purlins, rolled from pre-galvanised strip, are a lighter alternative to hot-rolled channels for roof and wall framing. Stainless steel channels need no coating and are used in hygienic, corrosive and architectural structures.

Quality checks

Before dispatch, channels are checked against the order for grade, size, length and quantity, and the heat numbers on the material are matched to the mill test certificates. Straightness and surface condition are inspected visually, and dimensions are checked against the tolerances of the product standard. For project orders, material can be marked with item or tag numbers, colour coded by grade, and packed by delivery area to make site receiving easier. Third-party inspection by the buyer's nominated agency can be arranged at our premises.

Documents and ordering

All structural sections are supplied with mill test certificates (MTC) showing heat number, chemistry and mechanical properties, and third-party inspection is available on request. Sections are bundled and tagged with grade, size and heat number; stainless sections are packed with protection to keep them separate from carbon steel and free of surface contamination.

Please give the material and grade, section designation or dimensions, length, finish, quantity and any inspection requirement.