Galvanised iron (GI) sheets are steel coated with zinc to resist rust. They are used for roofing, ducting, panels, enclosures and light structures. The price depends on thickness and - just as much - on how much zinc is on the steel, so the coating must be in every quote.
| Product | Notes |
|---|---|
| GI plain coil / sheet | Flat galvanised steel, cut to length or in coils |
| GI corrugated sheet | Profiled roofing and cladding sheet |
| GP / GC sheet | Galvanised plain / galvanised corrugated - trade names for the above |
| Galvalume (zinc-aluminium) | Aluminium-zinc coated sheet, longer life in many climates |
| Colour coated (PPGI / PPGL) | Painted galvanised or galvalume sheet - a separate category on the portal |
Under IS 277, the coating is written as a Z number - the total zinc in grams per square metre on both sides. Z120, Z180 and Z275 are common: the higher the number, the longer the sheet resists rust, and the higher the price. Two quotes for "0.5 mm GI" are not comparable unless the coating is the same.
Steel weight = length (m) x width (m) x thickness (mm) x 7.85 kg, plus the zinc (a Z275 coating adds 0.275 kg per square metre of sheet). Thin-gauge sheets are often quoted per sheet or per running metre - convert to rupees per tonne to compare.
On Indian Steel Portal you float one inquiry for GI sheets or coils - grade, sizes, quantity, preferred makes, delivery city and payment terms. KYC-verified mills, stockists and traders quote against it in a live reverse auction with a minimum decrement and a soft-close, ranked L1 to L4 on landed cost. You award L1 or any ranked bidder, and the deal note - with GST, MTC and weighment terms - is generated for both sides.
Float a GI inquiry - freeHR coils and sheetsIt means 275 grams of zinc per square metre, counted on both sides together, as per IS 277. Higher Z numbers mean more zinc and longer rust protection.
Galvanised flat-rolled steel 600 mm or wider falls under HSN 7210 (narrower under 7212), at 18% GST.
GI has a zinc coating; galvalume has a zinc-aluminium alloy coating, which generally lasts longer against corrosion for roofing.
Roofing commonly uses around 0.40 to 0.63 mm, but follow your designer or roofing contractor's specification and wind loads.
Both. Mills and large stockists sell by the tonne; retailers often sell per sheet. Convert to Rs per tonne at the same coating to compare.
Last updated 8 October 2026.
