We are Riddhi Siddhi Impex, a Mumbai-based Stainless Steel 309 Shims manufacturer and supplier, established in 2002. Our slitting lines produce 309 shim stock to ASTM A240 / ASME SA-240 in gauges from 0.03-5 mm, while the width is held within ±0.1 mm. As an ISO 9001, 14001, and 45001 certified company, we have a supply capacity of 400-500 tonnes, with ready stock and EN 10204 Type 3.1 / 3.2 mill test certificates on request.
Stainless Steel 309 shims are thin, flat spacers slit from a heat-resistant austenitic grade alloyed with 22 to 24% chromium and 12 to 15% nickel. In composition, its chromium and nickel content places it between Grades 304 and 310S. The chromium oxide film resists scaling to roughly 1095 °C continuous and 980 °C intermittent, and density stays near 8.0 g/cm³. Maintenance crews fit these high-temperature Stainless Steel Shims wherever a set clearance must survive repeated firings: furnace fixtures, expansion joints, and burner mounts. Typical uses of Stainless Steel 309 shims include sealing, spacing, alignment, and wear compensation in extreme heat environments.
As a reliable Stainless Steel 309 Shim supplier, every 309 stainless steel shim we offer starts as a source coil on our own slitting lines. Material leaves in annealed soft condition to ASTM A240, any width from 3 mm to 2000 mm. Buyers pick from BA, 2B, Matte, and Scotch-Brite surfaces. A documented quality system follows each coil from inward inspection to dispatch.
We provide AISI 309 shim stock to ASTM A240 in an annealed condition. These can be slit to your exact width or supplied flat, featuring four surface finishes and four edge options.
| Parameter | Details |
|---|---|
| Standard | ASTM A240 / ASME SA-240 |
| 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, Scotch-Brite |
| Supply Forms | Cold rolled (CR) |
| Edge Options | Slit edge, Mill edge, Deburred edge, Round edge |
The high Chromium (22.0%-24.0%) content builds a protective scale that allows these shims to perform reliably at furnace temperatures, while the Nickel (12.0%-15.0%) content stabilises the austenitic structure through intense thermal cycling.
| Element | Composition (%) |
|---|---|
| Chromium (Cr) | 22.0 - 24.0 |
| Nickel (Ni) | 12.0 - 15.0 |
| Manganese (Mn) | 2.00 max |
| Silicon (Si) | 0.75 max |
| Nitrogen (N) | 0.10 max |
| Carbon (C) | 0.20% |
| Phosphorus (P) | 0.045 max |
| Sulphur (S) | 0.030 max |
SS 309 shims ship in the annealed condition only and do not carry a temper ladder. A 40% minimum elongation with hardness capped at 217 HBW lets the material be blanked and formed cleanly, while 515 MPa minimum tensile strength gives the finished shim its load-bearing strength.
| Property | Value |
|---|---|
|
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)
|
217 HBW / 95 HRB |
For buyers working with international specifications, the same raw coil in stock complies with UNS S30900, European 1.4833, and Japanese SUS 309 designations, ensuring seamless cross-border substitution.
| Country / Standard | Designation |
|---|---|
| USA (UNS) | S30900 |
| Europe (EN) | X12CrNi23-13 |
| Germany (W.Nr) | 1.4833 |
| Japan (JIS) | SUS 309 |
| China (GB) | 06Cr23Ni13 |
| Russia (GOST) | 20Х23Н13 |
5 industries use the 309 SS shims we slit. Each values the grade for scaling resistance and steady dimensions at temperatures where a 304 spacer would oxidise away.
Heat-treatment shops shim basket supports, tray runners, and muffle joints with Alloy 309 shims. The material holds its gauge through quench-and-reheat cycles that thin out lower-alloy spacers within months, so fixture alignment survives between rebuilds.
Burner registers and duct expansion joints need packing pieces that keep the designed gap as steel grows and shrinks with every firing. A 309 stainless steel shim slit to ±0.1 mm sets that clearance accurately and resists the flame-side oxidation that erodes plain spacers.
Power stations place SS 309 shims under baffle plates, sootblower mounts, and tube supports in flue-gas paths. High chromium slows oxide growth on hot faces. Spacing stays true through load cycling, which keeps tube alignment inside inspection limits.
Refinery heaters burning sulphur-bearing fuel punish nickel-rich spacers, because nickel forms low-melting sulphides in these atmospheres. With nickel capped at 15%, 309 SS shims tolerate such flue gases better than richer heat-resisting alloys.
Kiln cars, calciner supports, and annealing-line fittings run hot for weeks at a stretch. Alloy 309 shims level these assemblies and prevent the abrasive dust of cement and ceramic lines, keeping refractory hardware seated where it was set.
Consignments are issued from our Mumbai and Taloja facilities in wooden cases or on pallets, cleared for 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, Letter of Credit (LC) |
| Certification | EN 10204 Type 3.1 / 3.2 available on request |
Stainless Steel 309 shims in India typically cost around ₹500-₹700 per kg, while export buyers generally pay about $3.7-6.5/kg. Nickel surcharges move the figure, along with gauge, width, finish, and quantity; bulk buyers earn discounts. Call or WhatsApp us for today's rate.
We manufacture Stainless Steel 309 shim stock in thicknesses from 0.03 mm up to 5 mm, slit to widths between 3 mm and 2000 mm. Anything thinner belongs to our SS 309 foils range.
The difference between 309 and 309S is carbon. Plain 309 permits 0.20%; 309S holds 0.08% maximum, and flat-rolled shim material under ASTM A240 follows the 309 limit.
Yes, SS 309 shims resist oxidation in continuous service up to about 1095 °C, or 980 °C where heating cycles on and off. Thin gauges scale faster, so allow a margin at the top of the range.
Our 309 stainless steel shims come in BA (bright annealed), 2B, Matte, and Scotch-Brite finishes. Edge options cover slit, mill, deburred, and round conditions.
Urgent orders are issued in 2 to 3 days against ready stock. Standard custom-slit deliveries take 4 to 5 days from our Mumbai and Taloja warehouses.
You can buy Stainless Steel 309 shims in India from us at Riddhi Siddhi Impex. As a manufacturer, stockist, and exporter, we hold ready material in Mumbai and send quotes within 24 hours by phone or WhatsApp.
