We are Riddhi Siddhi Impex, a Mumbai-based Alloy 20 Shim manufacturer and supplier, established in 2002. We precision-slit this niobium-stabilised nickel-iron-chromium product to ASME SB-463 in thicknesses from 0.03 mm to 5 mm. Our ISO 9001, 14001, and 45001-certified firm carries ready stock and holds a supply capacity of 400 to 500 tons monthly.
Alloy 20 Shims are thin, flat spacers slit from an austenitic nickel-iron-chromium alloy carrying copper and molybdenum, stabilised by niobium. Copper and molybdenum improve resistance to reducing acids, particularly sulphuric acid, primary sulphuric acid, while chromium adds oxidising resistance. Niobium at eight times the carbon content locks up carbon, so welded assemblies resist intergranular corrosion. The grade holds a density of 8.05 g/cm³. Fabricators fit these Shims wherever a gap needs filling accurately in acid-service equipment.
As a reliable Alloy 20 shim supplier, we slit every 20Cb-3 shim in-house on our own lines. Material leaves in soft annealed condition to ASME SB-463, in any width from 3 mm to 2000 mm. Buyers choose BA, 2B, or Matte surfaces with slit, deburred, or round edges. A documented quality system governs each stage, from source coil inspection through final dispatch.
We provide ASME SB-463 Alloy 20 shim stock in soft annealed condition, with a choice of surface finishes and edge conditions, supplied in coil to match your production line.
| Parameter | Details |
|---|---|
| Standard | ASME SB-463 |
| Thickness | 0.03 mm to 5 mm |
| Width | 3 mm to 2000 mm |
| Width Tolerance | ±0.1 mm |
| Condition | Soft / Annealed |
| Surface Finish | BA (Bright Annealed), 2B, Matte |
| Edge | Slit edge, Deburred edge, Round edge |
| Supply form | Cold Rolled |
Copper sets this grade apart. UNS N08020 Shims carry 3.0 to 4.0% copper with 2.0 to 3.0% molybdenum, and together they resist sulphuric acid across a wide range of concentrations. The full ASME SB-463 composition appears below.
| Element | Composition (%) |
|---|---|
| Nickel (Ni) | 32.0 to 38.0 |
| Chromium (Cr) | 19.0 to 21.0 |
| Iron (Fe) | Balance |
| Copper (Cu) | 3.0 to 4.0 |
| Molybdenum (Mo) | 2.0 to 3.0 |
| Niobium + Tantalum (Nb+Ta) | 8×C min, 1.00 max |
| Manganese (Mn) | 2.00 maxf |
| Silicon (Si) | 1.00 max |
| Carbon (C) | 0.07 max |
| Phosphorus (P) | 0.045 max |
| Sulphur (S) | 0.035 max |
Annealed N08020 shim stock provides a minimum tensile strength of 551 MPa with good ductility for precision spacing applications. ASME SB-463 does not specify yield strength below 0.51 mm thickness, so values for thinner gauges remain indicative.
| Property | Value |
|---|---|
|
Tensile Strength, minimum
|
551 MPa (80 ksi) |
|
Yield Strength (0.2% offset), minimum
|
241 MPa (35 ksi) |
|
Elongation in 50 mm, minimum
|
30% |
International buyers can cross-reference UNS N08020 Shims against their own regional standard using the table below. Every 20Cb-3 shim we slit meets these designations.
| Country / Standard | Designation |
|---|---|
| USA (UNS) | N08020 |
| Europe (EN) | NiCr20CuMo |
| Germany (W.Nr) | 2.4660 |
These 4 industries specify most of the Nickel Alloy 20 shims we slit. In each case, buyers select the grade for its sulphuric acid resistance, resistance to chloride stress corrosion cracking, and stabilised welds.
Chemical plants fit Alloy 20 Shims around flanges, pump housings, and heat exchanger parts exposed to sulphuric and phosphoric acids. The copper and molybdenum hold up in reducing acids that corrode stainless steel, and niobium keeps welded seams free of intergranular attack. A shim slit to ±0.1 mm seats without on-site trimming.
Pharmaceutical fabricators use Nickel Alloy 20 Shims to align mixing components and heat exchanger parts that contact acidic intermediates and cleaning agents. The stabilised austenitic structure holds its corrosion resistance through repeated clean-in-place cycles, so process fluids stay uncontaminated and assemblies keep accurate clearances.
Fabricators place Alloy 20 Shims into tubesheet stacks, vessel linings, and support faces handling hot acidic media. Resistance to both reducing and oxidising conditions lets one shim material serve duties that would otherwise need two, while tight thickness control keeps stack-up calculations accurate.
Refinery builders specify UNS N08020 Shims for acid-service sealing faces and separator components in sour crude service. The high nickel base resists chloride stress corrosion cracking, while copper counters the reducing acids formed during refining. Precise thickness keeps flange and separator alignment within tolerance.
Export orders leave from Mumbai and Taloja, packed in wooden cases or on pallets.
| 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 on request |
Alloy 20 Shims in India typically cost around ₹1,300 to ₹1,800 per kg, while international buyers generally pay about $15 to $23 per kg. The figure tracks global nickel rates, and thickness, width, finish, and quantity all move it. Volume discounts apply to bulk orders, so call or WhatsApp us for today's rate.
We slit high-grade alloy 20 shim stock from 0.03 mm to 5 mm thick and to any custom width between 3 mm and 2000 mm (held to ±0.1 mm). Anything thinner than 0.03 mm falls directly under our dedicated Alloy 20 foil range.
Alloy 20 Shims are covered by ASME SB-463 for UNS N08020 plate, sheet, and strip, which sets the chemistry and mechanical minimums for the shim stock we slit.
Some of the surface finishes we offer are BA, 2B, and Matte. Round or deburred edges suit sealing and gasket work where a sharp slit edge would damage adjacent parts.
You can source Alloy 20 Shims in India from us at Riddhi Siddhi Impex. Our Mumbai warehouse holds N08020 shim inventory on the shelf, ready for immediate dispatch. As a manufacturer, stockist, and exporter, we serve buyers across India and export overseas. Phone or WhatsApp us; we can provide quotations within 24 hours.
