We are Riddhi Siddhi Impex, a Mumbai-based supplier and stockist of Monel 400 Sheets & Plates, established in 2002. We hold ready stock of this nickel-copper alloy to ASTM B127 / ASME SB-127, in sheets from 3.8 mm and plates in heavier gauges. 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.
Monel 400 sheets and plates are nickel-copper alloy flat products holding at least 63.0% nickel and 28.0 to 34.0% copper. This solid-solution grade is not hardenable by heat treatment, so it strengthens through cold work alone. The high nickel and copper content resists hydrofluoric acid, seawater, and reducing conditions that corrode stainless steel. Alloy 400 also keeps its toughness from cryogenic temperatures to about 480 °C. Monel 400 sheets and plates are used in power generation and marine applications.
We stock this Monel Sheet and Plate as cold-rolled sheets from 3.8 mm and hot-rolled plates in heavier gauges, in widths up to 2000 mm. Material ships annealed to ASTM B127, with a pickled or bright annealed finish on cold-rolled sheets and an annealed oxide or descaled surface on hot-rolled plates, each supplied with a mill test certificate. Custom slitting trims sheets to your required width.
We provide ASTM B127 Monel 400 plate and UNS N04400 sheet in the annealed condition, across standard mill widths.
| Parameter | Details |
|---|---|
| Standard | ASTM B127 / ASME SB-127 |
| General Requirements | ASTM B906 |
| Thickness (Sheets, CR) | 3.8 mm to 6.35 mm |
| Thickness (Plates, HR) | Above 6.35 mm |
| Width | Up to 2000 mm |
| Width Tolerance | Per ASTM B906; ±0.1 mm on custom slit widths |
| Condition | Annealed (standard mill condition) |
| Surface Finish | Pickled or bright annealed (CR sheets); annealed with oxide or descaled surface (HR plates) |
| Form | Hot-Rolled Plates, Cold-Rolled Sheets |
Nickel and copper define this grade. UNS N04400 carries at least 63.0% nickel with 28.0 to 34.0% copper, and this pairing gives the alloy its resistance to reducing acids and seawater. The nominal composition of UNS N04400 to ASTM B127 appears below.
| Element | Composition (%) |
|---|---|
| Nickel (plus cobalt) | 63.0 min |
| Copper (Cu) | 28.0 to 34.0 |
| Iron (Fe) | 2.50 max |
| Manganese (Mn) | 2.00 max |
| Carbon (C) | 0.30 max |
| Silicon (Si) | 0.50 max |
| Sulphur (S) | 0.024 max |
Annealed N04400 plate and sheet meet a minimum tensile strength of 485 MPa, with yield and elongation minimums set by the standard. The ASTM B127 annealed minimums appear below.
| Property | Value |
|---|---|
|
Tensile Strength, minimum
|
485 MPa (70 ksi) |
|
Yield Strength (0.2% offset), minimum
|
195 MPa (28 ksi) |
|
Elongation in 50.8 mm (2 in.), minimum
|
35% |
|
Melting Range (typical)
|
1300 to 1350 °C |
International buyers can cross-reference UNS N04400 or W.Nr 2.4360 against their own regional standard using the table below.
| Country / Standard | Designation |
|---|---|
| USA (UNS) | N04400 |
| Europe (EN) | NiCu30Fe |
| Germany (W.Nr) | 2.4360 |
| Japan (JIS) | NW4400 |
| United Kingdom (BS) | NA 13 |
These four industries use the Monel 400 sheets and plates we supply, each drawing on the alloy's resistance to seawater, hydrofluoric acid, and reducing media.
Marine fabricators specify Alloy 400 plate for seawater piping, pump and valve bodies, and offshore hardware. UNS N04400 resists flowing seawater and chloride stress corrosion cracking, so it holds up in saline service where stainless steels suffer pitting and stress corrosion cracking. In stagnant seawater, fouling and localised pitting can occur, so flowing service suits the grade best.
Chemical plants build tanks, vessels, and heat exchanger parts from Monel 400 sheet where hydrofluoric and sulphuric acids attack lesser metals. The nickel-copper matrix resists reducing acids, extending equipment life in aggressive process streams.
Oil and gas operators fit Monel 400 plate into separators, pressure housings, and wellhead components exposed to hydrogen sulphide and brine. The high nickel base withstands sour, chloride-bearing service that can crack conventional austenitic grades.
Power plants use Alloy 400 sheet for feedwater heaters, condenser parts, and steam-side components. The grade handles both seawater cooling circuits and reducing acid duty, covering two service demands with one material.
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 |
Monel 400 Sheets & Plates price in India is around ₹1,700 to ₹2,600 per kg, or roughly $20 to $31 per kg for international buyers. The figure tracks global nickel and copper rates, and thickness, width, finish, and quantity all affect the final price. Call or WhatsApp us for today's rate and volume discounts.
Monel 400 sheets and plates are covered by ASTM B127 and its ASME equivalent SB-127 for nickel-copper alloy (UNS N04400) plate, sheet, and strip, with ASTM B906 for general requirements. The standard sets the chemistry, mechanical minimums, and tolerances.
We stock Monel 400 cold-rolled sheets from 3.8 mm to 6.35 mm and hot-rolled plates in heavier gauges, in widths up to 2000 mm, with narrower widths by custom slitting.
Yes, Monel 400 plates resist flowing seawater, brackish water, and marine atmospheres, and the alloy resists chloride stress corrosion cracking, which makes it a proven choice for marine and offshore applications. In stagnant seawater, fouling and localised pitting can occur, so flowing service suits the grade best.
The difference is mainly in thickness. Under ASTM B127, cold-rolled sheet runs up to 6.35 mm, and plate covers heavier gauges; material between 4.8 mm and 6.35 mm may be furnished as sheet or plate. Sheets are usually cold-rolled and plates hot-rolled, and both conform to ASTM B127 with the same UNS N04400 chemistry.
We supply cold-rolled Monel 400 sheets with a pickled or bright annealed finish, and hot-rolled plates with an annealed oxide or descaled surface, per ASTM B127.
You can source Monel 400 sheets and plates in India from us at Riddhi Siddhi Impex. Our Mumbai warehouse holds N04400 stock for immediate dispatch. As a Monel 400 plate supplier, stockist, and exporter, we serve buyers across India and abroad. Get a quote within 24 hours.
