We are Riddhi Siddhi Impex, a Mumbai-based manufacturer and supplier of Stainless Steel 347 Strips, established in 2002. Our slitting lines process niobium-stabilised austenitic strip to ASTM A240 / ASME SA-240 in widths from 3 mm, held to ±0.1 mm. As an ISO 9001, 14001, and 45001 certified company, we hold a monthly supply capacity of 400-500 tons, with EN 10204 Type 3.1 / 3.2 mill test certificates on request.
Stainless Steel 347 strips are narrow, flat-rolled austenitic products stabilised with niobium at a minimum of ten times the carbon content. That addition ties carbon into stable carbides, so weld zones resist intergranular attack through the 427 to 816 °C sensitisation band. General corrosion resistance is close to Type 304, while creep strength runs well above it. Fabricators choose the grade for thin-welded parts that run hot. These stainless steel strips are used in aerospace components, food processing equipment, and more.
As a reliable stainless steel 347 strips manufacturer and supplier, we slit these strips on our own lines rather than melt the alloy, working from parent coils sourced from reputed primary mills. Material leaves in the soft annealed condition, 0.03 mm to 5 mm thick, in BA, 2B, and Matte with test papers on request.
We provide ASTM A240 Type 347 strips in the annealed soft condition, with three surface finishes and four edge options, precision-slit to width from ready Mumbai stock.
| Parameter | Details |
|---|---|
| Standard | ASTM A240 / ASME SA-240, AMS 5512 |
| Thickness | 0.03 mm to 5 mm |
| Width | 3 mm to 2000 mm |
| Width Tolerance | ±0.1 mm |
| Condition | Annealed (Soft) |
| Surface Finish | BA (Bright Annealed), 2B, Matte |
| Edge | Slit edge, Mill edge, Deburred edge, Round edge |
| Supply Forms | Hot rolled and Cold rolled |
Niobium, also known as columbium in older references, is the working element in this grade. It grabs carbon before chromium can, leaving the full 17 to 19% chromium in solution for corrosion protection.
| 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 to 19.00 |
| Nickel (Ni) | 9.00 to 13.00 |
| Niobium (Nb) | 10xC min, 1.00 max |
| Iron (Fe) | Balance |
Annealed SS 347 strips deliver 515 MPa minimum tensile strength with 40% elongation, giving generous deep-draw and bending headroom. No temper ladder applies to this grade; strips ship soft.
| 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 |
Buyers working to European, Japanese, or Chinese standards can cross-reference UNS S34700 strip below. Every designation listed points to the same niobium-stabilised austenitic chemistry.
| 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 use most of the Stainless Steel 347 winding strips we slit. Industrialists pay for weld-zone stability and creep strength under sustained heat.
Refinery fabricators wrap 347 stainless strips into expansion joints, exchanger baffles, and recovery-unit parts that idle and restart. When sulphide scale meets air and moisture during shutdowns, polythionic acid attacks unstabilised grades. The stabilised structure resists that failure mode.
Boiler shops line superheater casings, stack liners, and flue expansion bellows with SS 347 strips. Creep strength through the 427 to 816 °C band keeps thin-welded sections in shape, with no post-weld anneal needed.
Chemical plants form Type 347 stainless steel strips into vessel linings, dosing equipment, and transfer piping for hot oxidising media. Grain-boundary chromium stays in place within the stabilised structure, so weld zones keep their acid resistance where standard austenitic grades are sensitive.
Aerospace builders order strip to AMS 5512 for exhaust stacks, firewalls, and collector rings. Stainless Steel 347 slit coil hold their strength through repeated heat cycling, and welded seams stay corrosion-resistant without further treatment.
Food equipment makers take 347 stainless strips for welded trim, conveyor components, and heat-cycled fittings around cookers. The grade cleans easily, doesn't shed carbides into product streams after welding, and stands up to hot caustic wash-down cycles.
Orders leave from our Mumbai and Taloja warehouses in wooden cases or on pallets, documented end-to-end.
| Parameter | Details |
|---|---|
| Packaging | Wooden cases, pallet packing |
| Incoterms | FOB, CIF, CFR, EXW Mumbai |
| Dispatch Points | Mumbai and Taloja warehouses |
| Standard Lead Time | 4 to 5 days |
| Urgent Dispatch | 2 to 3 days |
| Payment Terms | Advance, credit, LC |
| Certification | EN 10204 Type 3.1 / 3.2 mill test certificates on request |
Stainless Steel 347 Strips price in India runs around ₹350-₹700 per kg, roughly $3.7-$7.35 per kg for export buyers. Nickel and niobium surcharges move the rate, as do thickness, width, finish, and volume. Call or WhatsApp us for today's figure.
We supply SS 347 strips in thicknesses from 0.03 mm to 5 mm and widths from 3 mm to 2000 mm, slit in-house to ±0.1 mm.
The difference between SS 347 strips and SS 321 strips lies in the stabiliser. Type 347 uses niobium while Type 321 uses titanium. Niobium carbides stay stable at higher temperatures, so the 347 strip keeps its intergranular corrosion resistance longer in service above 700 °C.
Yes, SS 347 strips can be welded without post-weld annealing. Niobium absorbs the carbon before chromium carbides can form in the heat-affected zone, so the weld keeps its corrosion resistance as deposited.
The maximum service temperature for Stainless Steel 347 Strips is around 870 °C continuous. Creep strength stays useful through the 427 to 816 °C band.
Our SS 347 strips conform to ASTM A240 / ASME SA-240, with AMS 5512 covered for aerospace orders. EN 10204 Type 3.1 / 3.2 mill test certificates are available on request.
You can source Stainless Steel 347 Strip Coils in India from us at Riddhi Siddhi Impex. Our Mumbai and Taloja warehouses hold 1.4550 steel strips ready for dispatch in 4 to 5 days, or 2 to 3 days for urgent needs. Phone or WhatsApp us and get a quote within 24 hours.
