We are Riddhi Siddhi Impex, a Mumbai-based supplier and stockist of Stainless Steel 347 Sheets & Plates, established in 2002. Our warehouses hold niobium-stabilised austenitic sheet and plate to ASTM A240 / ASME SA-240, from 3.8 mm and above in thickness and in widths up to 2000 mm. As an ISO 9001, 14001, and 45001 certified company, we hold a supply capacity of 400-500 tonnes monthly and export to 60+ countries. We also provide EN 10204 Type 3.1 / 3.2 mill test certificates on request.
Stainless Steel 347 sheets and plates are flat-rolled austenitic stainless steel holding 17-19% chromium and 9-13% nickel, stabilised with niobium at ten times the carbon content minimum. Niobium, once called columbium, holds carbon into stable carbides, so weld seams resist intergranular corrosion through the 427 to 816 °C sensitisation band. General corrosion resistance matches Type 304, while creep strength is well past it, so fabricators pick UNS S34700 flat product for hot welded equipment. Stainless Steel 347 sheets and plates are typically used for hot-welded equipment like aircraft exhaust manifolds and boilers.
We stock this material rather than roll it, sourcing from reputed primary mills and holding both forms in Mumbai. Cold-rolled sheets cover 3.8 mm to 6 mm; hot-rolled plates continue to heavier gauges. Products ship annealed, with EN 10204 Type 3.1 / 3.2 mill test certificates on request.
We provide industrial-grade stainless steel sheets and plates matching the ASTM A240 Type 347 specification in the annealed mill condition, six surface finishes, and custom dimensions supplied from ready Mumbai stock.
| Parameter | Details |
|---|---|
| Standard | ASTM A240 / ASME SA-240, AMS 5512 |
| Thickness (Sheets, CR) | 3.8 mm to 6 mm |
| Thickness (Plates, HR) | 6 mm and above |
| Width | 3 mm to 2000 mm |
| Width Tolerance | ±0.1 mm |
| Condition | Annealed (standard mill) |
| Surface Finish | 2B, BA (Bright Annealed), Scotch-Brite, Matte, Matte PVC, Skin Pass |
| Supply Forms | Hot rolled and Cold rolled |
| Edge | Mill edge |
| Form | Sheets, Plates |
The niobium addition carries this grade. Added at a minimum of ten times the carbon content, niobium captures carbon as stable carbides and preserves chromium in solid solutions.
| Element | Composition (% by weight) |
|---|---|
| Carbon (C) | 0.08 max |
| Manganese (Mn) | 2.00 max |
| Phosphorus (P) | 0.045 max |
| Sulphur (S) | 0.030 max |
| Silicon (Si) | 0.75 max |
| Chromium (Cr) | 17.00-19.00 |
| Nickel (Ni) | 9.00-13.00 |
| Niobium (Nb) | 10xC min, 1.00 max |
| Iron (Fe) | Balance |
Annealed SA-240 Type 347 plate holds 515 MPa minimum tensile strength with 40% elongation. Sheets carry identical minimums, so pressing and folding behaviour stays predictable across gauges.
| Property | Value (Annealed) |
|---|---|
|
Tensile Strength, minimum
|
515 MPa (75 ksi) |
|
Yield Strength (0.2% offset), minimum
|
205 MPa (30 ksi) |
|
Elongation in 50 mm, minimum
|
40% |
|
Hardness, maximum
|
201 HBW / 92 HRB |
International buyers can cross-reference UNS S34700 sheets and plates using the table below. We supply every designation listed.
| Country / Standard | Designation |
|---|---|
| USA (UNS) | S34700 |
| Europe (EN) | X6CrNiNb18-10 |
| Germany (W.Nr) | 1.4550 |
| Japan (JIS) | SUS347 |
| China (GB) | 06Cr18Ni11Nb |
| Russia (GOST) | 08Х18Н12Б |
These 5 industries utilise most of the SS 347 sheets and plates we supply. Each needs welded flat product that keeps corrosion resistance under sustained heat.
Refiners fit Alloy 347 plate into fluid catalytic cracking internals, recovery columns, and exchanger shells that idle and restart. During shutdowns, sulphide scale meets air and moisture to form polythionic acid; the stabilised grade resists the resulting stress corrosion cracking.
Process plants line reactors, mixing vessels, and transfer ducting with 347 stainless steel plate wherever hot oxidising media flow. Weld zones don't surrender their grain-boundary chromium, so acid attack finds no path even after years above 500 °C.
Boiler shops build superheater casings, baffles, and expansion joints from SS 347 plate. The grade cycles between ambient and red heat without scaling, and its creep strength across the 427 to 816 °C band keeps welded panels true for years.
Aircraft builders order AMS 5512 sheet for jet pipe shrouds, collector rings, and engine bay heat shields. Niobium stabilisation preserves weld-seam corrosion resistance through repeated thermal cycling, and thin cold-rolled gauges form cleanly over compound curves.
Food and pharmaceutical plants pick Type 347 stainless steel sheet for steam-sterilised vessels, driers, and heated mixing equipment. Repeated autoclave cycles would sensitise an ordinary austenitic grade; the stabilised structure keeps product-contact surfaces smooth and non-contaminating.
Export orders leave from Mumbai and Taloja in wooden cases or on pallets, documented for sea.
| Parameter | Details |
|---|---|
| Packaging | Wooden cases, pallet packing |
| Incoterms | FOB, CIF, CFR, EXW Mumbai |
| Dispatch Points | Mumbai and Taloja warehouses |
| Standard Lead Time | 4-5 days |
| Urgent Dispatch | 2-3 days |
| Payment Terms | Advance, credit, LC |
| Certification | EN 10204 Type 3.1 / 3.2 mill test certificates on request |
Stainless Steel 347 Sheets & Plates price in India is roughly ₹210 to ₹350 per kg, which is about $3.0 to $5.1 per kg depending on supplier and product form for export orders. The figure tracks nickel and niobium surcharges; thickness, finish, and volume shift it further. Call or WhatsApp us for today's rate.
We stock Stainless Steel 347 Sheets & Plates from 3.8 mm and above, in widths up to 2000 mm. Custom dimensions are available on request.
The difference between SS 347 and SS 347H sheets and plates lies in carbon. Grade 347 caps carbon at 0.08% maximum, while 347H holds 0.04-0.10% for higher creep strength above 540 °C. Both fall under ASTM A240.
SS 347 sheets and plates compare with SS 321 as the two stabilised austenitic grades: 347 uses niobium where 321 uses titanium. Niobium carbides stay stable at higher temperatures, so 347 holds its intergranular corrosion resistance longer in hot service.
Yes, SS 347 plates can be welded without post-weld heat treatment. Niobium already holds the carbon, so chromium carbide precipitation at weld grain boundaries is greatly reduced. Matching ER347 filler keeps the joint as stable as the parent plate.
You can source Stainless Steel 347 Sheets & Plates in India from us at Riddhi Siddhi Impex, a supplier, stockist, and exporter. Our Mumbai and Taloja warehouses hold 1.4550 sheets and plate ready for dispatch in 4-5 days, or 2-3 days urgent. Phone or WhatsApp us; quotes will be provided within 24 hours.
