We are Riddhi Siddhi Impex, a Mumbai-based manufacturer and supplier of Stainless Steel 347 Shims, established in 2002. Our lines slit niobium-stabilised austenitic stock to ASTM A240 / ASME SA-240, from 0.03 mm to 5 mm thick. As an ISO 9001, 14001, and 45001 certified company with a monthly supply capacity of 400-500 tonnes, we export to 60+ countries, with EN 10204 Type 3.1 / 3.2 mill test certificates on request.
Stainless Steel 347 shims are thin austenitic spacers stabilised with niobium, historically called columbium, added at ten times the minimum carbon content. Niobium binds carbon as stable carbide, leaving the 17 to 19% chromium free to fight intergranular attack across the 427 to 816 °C sensitisation band. General corrosion resistance is close to Type 304, while hot strength ranges well beyond it. Fitters place 347 shim stock beside welds and in joints that cycle hot. These Stainless Steel Shims are used in furnace components, aerospace applications and more.
Every shim leaves its own slitting lines. Material ships annealed soft only, since 347 carries no ASTM A666 temper ladder, in any width from 3 mm to 2000 mm at ±0.1 mm. Deburred and round edges suit gasket faces, and AMS 5512 stock covers aerospace orders.
We provide ASTM A240 Type 347 shims in the annealed soft condition, with the finishes and edges shown below.
| 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) |
| Supply Forms | Cold rolled |
| Surface Finish | BA (Bright Annealed), 2B, Matte, Scotch-Brite |
| Edge | Slit edge, Mill edge, Deburred edge, Round edge |
Niobium added at ten times the carbon minimum, it forms carbides before chromium can, so grain boundaries keep their corrosion guard through welding and heat cycling.
| 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 Alloy 347 shims stretch 40% minimum, so they punch and bend without cracking. Below the standard's thin-gauge testing threshold, treat the figures as indicative.
| 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 ordering UNS S34700 shims, 1.4550 shims, or AISI 347 shim stock can cross-check every regional designation in the table below.
| 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 347 stainless steel shims leaving our lines, picking the grade for weld-zone stability and creep strength in hot service.
Refinery crews pack SS 347 shims under exchanger supports, pump bases, and flange gaps in units that idle and restart. The grade resists polythionic acid stress corrosion cracking during shutdowns, a failure mode that catches unstabilised spacers once sulphide scale meets moist air.
Aerospace shops stack AMS 5512 shims in exhaust assemblies, collector rings, and actuator housings. A 347 shim slit to ±0.1 mm needs no site trimming, and niobium stabilisation preserves weld-seam corrosion resistance through repeated heat cycling.
Boiler and turbine fabricators set tube supports, expansion bellows, and casing joints on 347 SS shims. Creep strength holds through the 427 to 816 °C band, so settings stay true for years without any post-weld anneal.
Chemical plants level reactor flanges, mixing vessel mounts, and transfer piping with Type 347 shims where lines carry hot oxidising media. The stabilised structure never gives up grain-boundary chromium, so shimmed weld zones resist post-sensitisation acid attack.
Furnace builders space burner mounts, retort flanges, and radiant tube supports with 347 shim stock. Oxidation resistance stays useful up to 870 °C, and the shims hold thickness where plain austenitic spacers scale and thin.
Shim consignments clear our Mumbai and Taloja warehouses within days, boxed for export sea freight.
| 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 Shims price in India runs around ₹300-₹750 per kg, roughly $3-$8 per kg for export buyers. The range is indicative; nickel and niobium surcharges, thickness, width, finish, and volume all move it. Call or WhatsApp our team for today's rate.
SS 347 shims are available from 0.03 mm to 5 mm thick, slit to any width between 3 mm and 2000 mm.
SS 347 shims differ from SS 321 shims in the stabilising element. Type 347 uses niobium, where 321 uses titanium, and niobium carbides stay stable at higher temperatures, so 347 keeps intergranular corrosion resistance longer above 700 °C.
The maximum service temperature for Stainless Steel 347 Shims is around 870 °C continuous. Creep strength stays useful through the 427 to 816 °C band.
Available finishes for 347 stainless steel shims include BA (Bright Annealed), 2B, Matte, and Scotch-Brite. Deburred or round edges suit gasket work where sharp slit edges would damage mating faces.
The price of SS 347 shims falls around ₹300-₹750 per kg in India and $8.5-$9.5 per kg for overseas buyers. Send your size and quantity for a firm figure.
You can source Stainless Steel 347 Shims in India from us at Riddhi Siddhi Impex. Ready 1.4550 shim stock sits in our Mumbai and Taloja warehouses for slitting and dispatch in 4 to 5 days. Phone or WhatsApp us and get a quote within 24 hours.
