Steel Sheets
GP Sheet
Flat steel sheet under a hot dip zinc coating, bought by workshops to be cut, bent and welded.
- Steel Sheets
- 2 sizes listed
- GI
- 3 brands stocked
- Own delivery, 34 blocks
GP is galvanised plain: flat steel that has been through a hot dip zinc bath, with no corrugations rolled into it. Jay Shree Infra deals in it at the Saharsa godown, in Tata Steel, whose GP sheet here is sold as Tata Kosh, and in SAIL. It is workshop material, bought flat and then cut, bent and welded, and the buyers behind it here are the local fabricators, the bigger fabrication shops, the thekedars and the project companies across Saharsa, Supaul and Madhepura. Trunk, box and almirah makers are among the steadiest buyers of this sheet, and they take it in every size the steel sheets rack carries. Which thickness is standing on a given morning is settled on the phone and never off a page.
The zinc is the point of the sheet and it carries a figure of its own, grams per square metre, alongside the thickness in millimetres. Run the same coated steel through a corrugating roll and it becomes GC sheet, the chadra on a shed roof, which is why one Indian Standard covers the two of them together. Hot rolled and cold rolled, the uncoated sheets, sit beside this one under steel sheets.
Thickness
SAIL's two plants, and what each one rolls
The published GP thickness against each SAIL plant, and the form it leaves the mill in.
Scroll the table sideways to see every column
| SAIL plant | Published thicknessmm | Leaves the mill as |
|---|---|---|
| SAIL Bokaro | ~0.4 to 2.0 | Coil / cut sheet |
| SAIL Rourkela | ~0.35 to 1.25 | Sheet |
Both rows are SAIL's own figures off its galvanised products page, and the tildes mark a band read off that published table. SAIL adds under it that other thickness and width combinations can be supplied by mutual consent. Read the table as what SAIL rolls and not as what is standing in Saharsa. Tata publishes its plain galvanised line, Galvano, at 0.45 to 2 mm and 1000 to 1520 mm wide, in full coil, slit coil, cut to length sheet and blanks, so the thin end below 0.45 mm belongs to Rourkela and the 2 mm end at SAIL is the Bokaro coil.
Kis kaam me lagta hai
SAIL's own application list for GP runs panelling, door frames, shutters, AC ducts, coolers, storage bins, drums, buckets, tubs and tanks. We stock it for the same jobs here: ducting, panels, cabinets, roofing components and general fabrication.
Shutters are on that list because the flat and formed parts around a rolling shutter come out of coated sheet. The lath sections themselves are a separate rack and a separate question, worked out on the shutter profile page. On a roof, what goes over the purlins is the corrugated sheet; the flat roofing components are cut from this one.
Zinc is measured, and the two mills print it differently
The coating is sold as mass over area, in grams per square metre. SAIL lists its coating classes at 80, 100, 120, 180, 200, 220, 275, 350, 450, 550 and 600 gsm. Tata publishes Galvano at 60 to 550 gsm and prints what that figure stands on: the total, both sides. A gsm number with no basis beside it cannot be set against one that has it.
One thickness can arrive in any of those classes, so the millimetres describe half the sheet. The class is its own line on the mill's test certificate, and it is worth asking for by number on every quote you are holding.
The grade letter is a second question
Tata publishes Galvano in six grades: CQ, DQ, DDQ, EDD, IF and high strength, without expanding what the letters stand for, and we go by the same letters. What they settle is how the sheet behaves under a press and a brake, which the millimetres do not tell you.
If the drawing carries a letter, say it on the call. If it does not, tell us what the sheet is being formed into, and the question goes to the mill instead of being guessed at the counter.
Slit, cut, or the whole coil
Sheet and coil are two forms of one material and the order has to name one. Tata lists Galvano as full coil, slit coil, cut to length sheet and blanks. SAIL rolls its GP as coil at Bokaro and as sheet at Rourkela, which is the practical reason the two rows above stop at different thicknesses. A cut only goes one way, so the form and the finished size are settled on the call, before anything is cut.
One line in the order covers both kinds
Galvanised steel sheets, plain and corrugated, are IS 277:2018, and the Steel and Steel Products (Quality Control) Order, 2024 carries that standard at serial 7 of Schedule 1, with immediate effect. The entry names both kinds in a single line and carves out no size and no profile, so the flat sheet sits inside it exactly as the roofing chadra does. The Order also asks that every consignment be accompanied by a test certificate bearing the Standard Mark, issued by a maker BIS has certified.
So the standard number by itself will not tell you which of the two sheets you are holding. The thickness and the coating class do, and both belong on that certificate. Ask us what came in with yours.
Brands
Tata Kosh on one side, two SAIL plants on the other
Tata Kosh is the name most GP sheet buyers here ask for, and it leads this wall for that reason. Not every thickness is in every name on a given day, so put the thickness and the finished size beside the name when you ring.
Both names need a word. Tata's GP sheet for trunk, box and almirah work is Tata Kosh; Tata also publishes a premium, zero spangle GP line called Galvano, and which of the two reaches this counter under the Tata name is what the bill and the marking say. Bokaro is a SAIL plant, not a maker of its own, and we mark GP against it as a plant. What else each of the two puts on our racks is on the SAIL and Tata Steel pages.
Sources
The two mills and the gazette itself
Every thickness, width, coating figure and grade letter above comes from the mills' own tables, and the standard entry from the gazette notification.
- SAIL's galvanised products page, with the plant thickness bands and the eleven coating classesSAIL
- Galvano, Tata's plain galvanised line, with its thickness, width, forms, grades and coating massTata Steel
- Steel and Steel Products (Quality Control) Order, 2024, S.O. 3716(E) of 29 August 2024Ministry of Steel
- Tata Kosh, Tata's retail GP sheet brand for trunk, box and grain silo fabricationTata Shaktee
Questions
GP ke sawal
GP aur GI sheet ek hi cheez hai?
They land on the same material. GP is galvanised plain, which is the word the mills print, and GI is the older galvanised iron word still used for the same sheet in the market. What neither of them means is the corrugated roofing chadra, which is GC. Say whichever word you were given and two more questions get us to the same sheet.
Coating ka gsm dono taraf ka hota hai ya ek taraf ka?
Tata prints its Galvano coating as 60 to 550 gsm and says in the same line that the figure is the total for both sides. SAIL's eleven classes, listed above, are published as gsm with no such note against them. So ask which basis a quoted number stands on before you weigh two of them, because one 275 and another 275 need not be the same coating.
Grade ka letter bhi batana padta hai?
On anything that has to bend or draw, yes. Tata publishes Galvano in CQ, DQ, DDQ, EDD, IF and high strength, and prints the letters without expanding them, so we do the same. Bring the letter off the drawing if there is one, and if there is not, tell us what the sheet is being formed into.
0.35 mm se patli GP sheet milegi?
That is under what SAIL and Tata publish for this sheet. SAIL's thinnest published GP is the 0.35 mm end of its Rourkela sheets, its Bokaro coil starts at 0.4 mm, and Tata publishes Galvano from 0.45 mm. A thinner figure on a quote is worth one question about whose sheet it is and how that thickness was measured. Read us the figure you were given.
Poora coil lena padega ya sheet me bhi ho jayega?
Both forms are rolled, so this one is a call and never a rule: the four forms Tata lists and the two SAIL plants are set out above. Tell us the form you want, the finished size, how many pieces and the village, and the load leaves in our own vehicle once the cut is settled.
Contact
Say what the sheet is going to become
Thickness is the easy half of a coated sheet. The job decides the coating class, and where the steel has to draw it decides the grade letter as well, and neither of those is on a tape measure. Tell us what is being made, the size you want it in, how many, and whether it is going out as sheet or as coil. Call +91 6202 967 218 for today's rate.
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