We are Riddhi Siddhi Impex, a Mumbai-based supplier and stockist of Alloy 20 Sheets & Plates, established in 2002. We hold ready stock of this niobium-stabilised nickel-iron-chromium alloy to ASTM A240 / ASME SB-463, in sheets from 0.8 mm thick and plates in heavier gauges, sourced from reputed primary mills. Our ISO 9001, 14001, and 45001-certified facility has a monthly supply capacity of 400 to 500 tonnes, and issues EN 10204 Type 3.1 mill test certificates as standard, with Type 3.2 on request.
Alloy 20 sheets and plates are austenitic nickel-iron-chromium alloy flat products with added copper and molybdenum, stabilised with niobium. The copper and molybdenum resist reducing acids, especially sulphuric acid, while chromium adds oxidising resistance. Niobium stabilises the alloy by combining with carbon, so welded fabrications resist intergranular corrosion without post-weld heat treatment. Typical applications include tanks, process equipment, heat exchangers, and storage vessels in chemical processing plants.
We stock this grade as cold-rolled sheets from 0.8 mm and hot-rolled plates in heavier gauges, up to 2000 mm wide (after slitting). Material ships in the stabilised annealed condition to ASME SB-463, in 2B or BA finishes on cold-rolled sheets and a hot rolled, annealed and pickled surface on plates, each supplied with a mill test certificate. Custom slitting trims sheets to your required width.
We provide ASME SB-463 Alloy 20 plate and UNS N08020 sheet in the stabilised annealed condition, with finishes matched to product form, across standard mill widths.
| Parameter | Details |
|---|---|
| Standard | ASTM A240 / ASME SB-463 |
| General Requirements | ASTM A480 |
| Thickness (Cold-rolled sheets) | 0.8 mm to 4.75 mm |
| Thickness (Hot-rolled plates) | 6 mm and above |
| Width (after slitting) | Up to 2000 mm |
| Width Tolerance | Per ASTM A480; ±0.1 mm on custom slit widths |
| Condition | Stabilised annealed per ASME SB-463 |
| Surface Finish | 2B, BA (cold-rolled sheets); hot rolled, annealed and pickled (plates) |
| Form | Hot-Rolled Plates, Cold-Rolled Sheets, Custom-Slit Sheets |
Nickel between 32 and 38% resists chloride stress corrosion cracking, while copper at 3 to 4% sets Alloy 20 apart in sulphuric acid. The nominal composition of UNS N08020 to ASME SB-463 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 max |
| Silicon (Si) | 1.00 max |
| Carbon (C) | 0.07 max |
| Phosphorus (P) | 0.045 max |
| Sulphur (S) | 0.035 max |
The mechanical properties below meet ASTM A240 / ASME SB-463 requirements. Stabilised annealed N08020 plate and sheet meet a minimum tensile strength of 551 MPa (80 ksi), with yield and elongation minimums set by the standard.
| Property | Value |
|---|---|
|
Tensile Strength, minimum
|
551 MPa (80 ksi) |
|
Yield Strength (0.2% offset), minimum
|
241 MPa (35 ksi) |
|
Elongation in 50.8 mm (2 in.), minimum
|
30% |
|
Hardness, maximum
|
217 HBW / 95 HRB |
|
Melting Range (typical)
|
1385 to 1443 °C |
International buyers can cross-reference UNS N08020 or W.Nr 2.4660 against their own regional standard using the table below.
| Country / Standard | Designation |
|---|---|
| USA (UNS) | N08020 |
| Europe (EN) | NiCr20CuMo |
| Germany (W.Nr) | 2.4660 |
These four industries widely use the Nickel Alloy 20 sheets and plates we supply, each drawing on the alloy's sulphuric acid resistance and resistance to chloride stress corrosion cracking.
Chemical plants build reactor linings, tanks, and pickling equipment from Alloy 20 sheet where sulphuric and phosphoric acids attack lesser metals. The copper and molybdenum help the alloy resist reducing acids, and niobium stabilisation keeps welded seams free of intergranular attack.
Pharmaceutical fabricators form Alloy 20 sheet into mixing vessels and heat exchangers that contact acidic intermediates and cleaning agents. The stabilised austenitic structure holds its corrosion resistance through repeated clean-in-place cycles, keeping process fluids uncontaminated.
Refinery operators specify Nickel Alloy 20 plates for acid-handling vessels and separators exposed to sour crude and sulphur compounds. The high nickel base resists chloride stress corrosion cracking, while copper counters the reducing acids formed in processing.
Power plant engineers select Alloy 20 plates for flue gas scrubbers and acid-service ducting where wet, acidic condensate corrodes standard stainless steel. Resistance to both reducing and oxidising conditions lets a single grade handle mixed acid duty.
Orders leave our Mumbai and Taloja warehouses in wooden cases or on pallets, ready 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, LC |
| Certification | EN 10204 Type 3.1 standard; Type 3.2 on request |
Alloy 20 sheets & plates price in India is around ₹1,300 to ₹2,000 per kg, or roughly $15 to $23 per kg for international buyers. The figure tracks global nickel rates, and thickness, width, finish, and quantity all affect the final price. Call or WhatsApp us for today's rate and volume discounts.
Alloy 20 Sheets and Plates are covered by ASTM A240 and ASME SB-463, with ASTM A480 for general flat-rolled requirements. These set the chemistry, mechanical minimums, and tolerances for UNS N08020.
The difference is mainly in thickness. Under ASME SB-463, material 4.76 mm and over classifies as plate; commercially, we supply cold-rolled sheets from 0.8 mm and hot-rolled plates in heavier gauges. Both conform to the standard with the same UNS N08020 chemistry.
We stock Alloy 20 cold-rolled sheets from 0.8 mm to 4.75 mm and hot-rolled plates in heavier gauges, in widths up to 2000 mm (after slitting).
Yes, Alloy 20 Sheets and Plates can be welded using TIG, MIG, and submerged arc methods with matching filler. The niobium stabilisation minimises carbide precipitation, so post-weld heat treatment is normally not required.
You can source Alloy 20 Sheets and Plates in India from us at Riddhi Siddhi Impex. Our Mumbai warehouse holds ready stock for immediate dispatch. As a supplier, stockist, and exporter, we serve buyers across India and abroad, with quotes within 24 hours.
