Stainless Steel, Duplex & Nickel Alloy Plates
Plate is flat material 3/16" (4.76 mm) and thicker, used for pressure-bearing walls, heavy sections and machined parts. Choose the family, then the grade. We supply stainless, duplex, nickel-alloy, chrome-moly and carbon steel plate as full plates or cut to size, with UT and third-party inspection on request.
- ASTM A480
- ASTM B906
- ASTM A20
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is plate, and how is it specified?
Plate is flat-rolled metal 3/16" (4.76 mm) and thicker, usually hot rolled, and is what pressure vessels, heat-exchanger tube sheets, flanges and structural parts are cut from. Stainless and duplex plate is ASTM A240; nickel-alloy plate follows B424, B443, B575 or B168; carbon and chrome-moly vessel plate follows ASTM A516 and A387, with general requirements in ASTM A20.
How to order plates: checklist
- Grade and specification — e.g. ASTM A240 2205 or ASTM A516 Gr 70
- Thickness × width × length, or cut-to-size drawing
- Heat treatment / condition — annealed, normalised, normalised & tempered
- Extra tests — ultrasonic (A578 / A435), impact (A20 S5), simulated PWHT (A20 S3)
- Cutting method and tolerance if cut to size
- Certificate — EN 10204 3.1 or 3.2
Plate by Material Family and Grade
Every plate page sits under its grade, and every grade under its family. Pick the family for your service, then open the grade's plate page for its standard, testing, cutting and weights.
Types of Plates
Plate Cut to Size
Most plate is bought as pieces: rectangles, strips, circles and rings cut from a full plate, each marked with the heat number of the plate it came from. Send finished sizes and your machining allowance, or a cutting list.
Plate Testing: UT, Flatness & Certificates
Plate for pressure parts is checked for internal soundness as well as chemistry. Ultrasonic testing to ASTM A578 (levels A, B, C, for plate 10 mm and over), A435 for carbon pressure-vessel plate, or EN 10160 (S0–S3 body, E0–E4 edge) is added on the order; flatness and dimensions follow ASTM A480, B906 or A20 depending on the material.
How Plate Standards Fit Together
Plate Weight by Grade
Weight (kg) = length (m) × width (m) × thickness (mm) × density. Nickel alloys are denser than stainless, so the same plate weighs more — it matters when you compare prices per kg and plan lifting.
| Grade | Density g/cm³ | 5 mm, kg/m² | 10 mm, kg/m² | 2000 × 1000 × 20 mm, kg |
|---|---|---|---|---|
| Inconel 825 | 8.14 | 40.7 | 81.4 | 326 |
| SS 904L | 7.95 | 39.8 | 79.5 | 318 |
| SS 304 | 8.00 | 40.0 | 80.0 | 320 |
| SS 304L | 8.00 | 40.0 | 80.0 | 320 |
| SS 310 / 310S | 7.90 | 39.5 | 79.0 | 316 |
| SS 316 / 316L | 8.00 | 40.0 | 80.0 | 320 |
| SS 321 | 7.92 | 39.6 | 79.2 | 317 |
| SS 347 | 7.96 | 39.8 | 79.6 | 318 |
| Duplex 2205 | 7.80 | 39.0 | 78.0 | 312 |
| Super Duplex 2507 | 7.80 | 39.0 | 78.0 | 312 |
| Inconel 600 | 8.47 | 42.4 | 84.7 | 339 |
| Inconel 625 | 8.44 | 42.2 | 84.4 | 338 |
| Inconel 718 | 8.19 | 40.9 | 81.9 | 328 |
| Incoloy 800 / 800H / 800HT | 7.94 | 39.7 | 79.4 | 318 |
| Hastelloy C276 | 8.89 | 44.5 | 88.9 | 356 |
| Hastelloy C22 | 8.69 | 43.4 | 86.9 | 348 |
| Monel 400 | 8.80 | 44.0 | 88.0 | 352 |
| Super Duplex S32760 | 7.84 | 39.2 | 78.4 | 314 |
| SA-516 Gr 70 | 7.85 | 39.3 | 78.5 | 314 |
| SA-387 Gr 11 Cl 2 | 7.85 | 39.3 | 78.5 | 314 |
| S275JR | 7.85 | 39.3 | 78.5 | 314 |
| S355J2+N | 7.85 | 39.3 | 78.5 | 314 |
| IS 2062 E250 / E350 | 7.85 | 39.3 | 78.5 | 314 |
Which Plate Grade for Which Service?
A starting point for selection; confirm with your design code and corrosion data.
| Service | Start with |
|---|---|
| Pressure vessels at moderate and lower temperatures | ASTM A516 Gr 70 |
| Hot refinery and boiler service | ASTM A387 Gr 11 Cl 2 |
| Structural steelwork | IS 2062 · S355J2+N |
| Process vessels in mild chlorides | SS 316L |
| Sulphuric and phosphoric acid vessels | SS 904L or Inconel 825 |
| Lighter vessel walls in chloride service | Duplex 2205 |
| Seawater tube sheets and offshore | Super duplex 2507 or Inconel 625 |
| Wet chlorine and mixed-acid reactors | Hastelloy C276 |
Plates Grades & Material Standards
| Grade | Material standard | Best for |
|---|---|---|
| Inconel 825 | ASTM B424 | Sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas |
| SS 904L | ASTM A240 | Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water |
| SS 304 | ASTM A240 | General corrosion resistance, food, water and architectural work |
| SS 304L | ASTM A240 | Welded tanks, piping and vessels in general corrosive service |
| SS 310 / 310S | ASTM A240 | Furnaces, burners and heat treatment at high temperature |
| SS 316 / 316L | ASTM A240 | Chloride-bearing process fluids, marine air and pharmaceutical service |
| SS 321 | ASTM A240 | High-temperature service between 425 and 815 °C |
| SS 347 | ASTM A240 | Welded high-temperature piping in refineries and power plants |
| Duplex 2205 | ASTM A240 | Strength with chloride resistance at a stainless-steel budget |
| Super Duplex 2507 | ASTM A240 | Seawater and high-chloride service where strength also matters |
| Inconel 600 | ASTM B168 | High-temperature oxidation, caustic and nuclear service |
| Inconel 625 | ASTM B443 | Seawater, high strength and high temperature in one alloy |
| Inconel 718 | ASTM B670 · AMS 5596 | Very high strength at temperatures up to about 650 °C |
| Incoloy 800 / 800H / 800HT | ASTM B409 | Furnaces, petrochemical heaters and high-temperature piping |
| Hastelloy C276 | ASTM B575 | The most aggressive mixed acids, wet chlorine and hypochlorite |
| Hastelloy C22 | ASTM B575 | Mixed oxidising and reducing acids, and weld overlays |
| Monel 400 | ASTM B127 | Seawater, hydrofluoric acid and marine service |
| Super Duplex S32760 | ASTM A240 | Seawater firewater, injection and offshore piping |
| SA-516 Gr 70 | ASTM A516 Gr 70 · ASME SA-516 | Boilers, pressure vessels and storage tanks |
| SA-387 Gr 11 Cl 2 | ASTM A387 Gr 11 Cl 2 · ASME SA-387 | Hot, high-pressure reactors and heat exchangers |
| S275JR | EN 10025-2 | General structures, frames and fabrication |
| S355J2+N | EN 10025-2 | Heavy structures, cranes and offshore frames |
| IS 2062 E250 / E350 | IS 2062 | Structures, fabrication and general engineering in India |
Guides, tools & standards for plates
Plates for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiPlates — questions buyers ask
What thickness is plate?
Under ASTM A480 and B906, flat material 3/16" (4.76 mm) and thicker is plate; thinner is sheet. Pressure-vessel plate to ASTM A20 (A516, A387) is defined by width and thickness — roughly 4.6 mm and over for plate wider than 48". EN plate (EN 10029) starts at 3 mm.
Can you cut plate to size?
Yes — rectangles, strips, circles and rings to your drawing or cutting list, with the heat number transferred to every piece.
Do you supply ultrasonically tested plate?
Yes. UT to ASTM A578 or EN 10160 can be added to the order, at the acceptance level your specification states, with the report supplied.
Which plate is used for pressure vessels?
Carbon steel vessels usually use ASTM A516 Gr 70 (with A387 chrome-moly for hot service). Corrosive service moves to stainless, duplex or nickel-alloy plate depending on the medium.
How do I calculate plate weight?
Length (m) × width (m) × thickness (mm) × density (g/cm³) gives kg. For stainless, density is about 7.9–8.0; for Inconel 825 it is 8.14.