Tubewell Steel & Engg. Co. is a leading manufacturer and stockist specializing in Alloy Steel Pipes, Tubes, Fittings and Flanges for critical industrial applications.
Tubewell Steel & Engg. Co. is a supplier and stockist of ASTM A387 / ASME SA387 alloy steel plates in Mumbai, India. These chromium-molybdenum plates are designed for welded boilers and pressure vessels operating at elevated temperatures, and are available in Class 1 and Class 2 strength levels across all popular grades.
Chromium-molybdenum plates for elevated-temperature pressure equipment
ASTM A387 (ASME SA387) covers chromium-molybdenum alloy steel plates intended primarily for welded boilers and pressure vessels designed for elevated-temperature service. Chromium content ranges from about 1% in Grade 12 to 9% in Grades 9 and 91, while molybdenum (0.5% to 1%) provides creep and rupture strength. The higher the chromium, the better the resistance to oxidation, sulphidation and high-temperature hydrogen attack.
Each grade is offered in two strength levels: Class 1 and the higher-strength Class 2 (Grade 91 is supplied as Class 2 only). Plates are delivered annealed, or normalized and tempered, with minimum tempering temperatures specified by the standard. General plate requirements such as dimensional tolerances, flatness and testing follow ASTM A20 / ASME SA20. Every plate is traceable to its heat and slab number and supplied with an EN 10204 3.1 mill test certificate. EN 10204 3.2 certification and third-party inspection can be arranged on request.
Standard supply range for ASTM A387 alloy steel plates
| Parameter | Details |
|---|---|
| Standard | ASTM A387, ASME SA387 |
| General Requirements | ASTM A20 / ASME SA20 |
| Grades | Grade 5, 9, 11, 12, 22, 91 |
| Class | Class 1, Class 2 (Grade 91 – Class 2 only) |
| Thickness | 3 mm to 150 mm (higher thickness on request) |
| Width | Up to 2500 mm (3000 mm on request) |
| Length | Up to 12000 mm |
| Forms | Sheet, Plate, Coil, Strip, Circle, Ring, Flat |
| Finish | Hot Rolled (HR), Cold Rolled (CR), Shot Blasted |
| Delivery Condition | Annealed, Normalized & Tempered |
| Cutting Services | Plasma, Gas / Oxy-fuel, Waterjet, Shearing, Profile Cutting to Drawing |
| Testing | Tensile, Hardness, Impact, UT (ASTM A435 / A578), PMI, Simulated PWHT |
| Certificates | EN 10204 3.1 / 3.2, IBR (where applicable), TPI Reports |
International equivalents of ASTM A387 plate grades
| Grade | Nominal Composition | ASTM / ASME | UNS | EN 10028-2 | W.Nr. | JIS G4109 |
|---|---|---|---|---|---|---|
| Gr 5 | 5Cr-0.5Mo | A387 / SA387 Gr 5 | K41545 | X12CrMo5 | 1.7362 | SCMV 6 |
| Gr 9 | 9Cr-1Mo | A387 / SA387 Gr 9 | K90941 | – | – | – |
| Gr 11 | 1.25Cr-0.5Mo-Si | A387 / SA387 Gr 11 | K11789 | 13CrMo4-5 | 1.7335 | SCMV 3 |
| Gr 12 | 1Cr-0.5Mo | A387 / SA387 Gr 12 | K11757 | 13CrMo4-5 | 1.7335 | SCMV 2 |
| Gr 22 | 2.25Cr-1Mo | A387 / SA387 Gr 22 | K21590 | 10CrMo9-10 | 1.7380 | SCMV 4 |
| Gr 91 | 9Cr-1Mo-V | A387 / SA387 Gr 91 | K90901 | X10CrMoVNb9-1 | 1.4903 | – |
Equivalents are the closest comparable grades; chemistry and mechanical limits are not identical. Please confirm suitability against your design code.
Weight %, heat analysis as per ASTM A387
| Grade | C | Mn | P | S | Si | Cr | Mo | Others |
|---|---|---|---|---|---|---|---|---|
| Gr 5 | 0.15 max | 0.30 – 0.60 | 0.025 max | 0.025 max | 0.50 max | 4.00 – 6.00 | 0.45 – 0.65 | – |
| Gr 9 | 0.15 max | 0.30 – 0.60 | 0.025 max | 0.025 max | 1.00 max | 8.00 – 10.00 | 0.90 – 1.10 | – |
| Gr 11 | 0.05 – 0.17 | 0.40 – 0.65 | 0.025 max | 0.025 max | 0.50 – 0.80 | 1.00 – 1.50 | 0.45 – 0.65 | – |
| Gr 12 | 0.05 – 0.17 | 0.40 – 0.65 | 0.025 max | 0.025 max | 0.15 – 0.40 | 0.80 – 1.15 | 0.45 – 0.60 | – |
| Gr 22 | 0.05 – 0.15 | 0.30 – 0.60 | 0.025 max | 0.025 max | 0.50 max | 2.00 – 2.50 | 0.90 – 1.10 | – |
| Gr 91 | 0.08 – 0.12 | 0.30 – 0.60 | 0.020 max | 0.010 max | 0.20 – 0.50 | 8.00 – 9.50 | 0.85 – 1.05 | Ni 0.40 max, V 0.18–0.25, Nb 0.06–0.10, N 0.030–0.070, Al 0.02 max |
Tensile requirements at room temperature as per ASTM A387
| Grade | Class | Tensile Strength | Yield Strength (min) | Elongation in 50 mm (min) |
|---|---|---|---|---|
| Gr 5 | Class 1 | 415 – 585 MPa (60 – 85 ksi) | 205 MPa (30 ksi) | 18% |
| Gr 5 | Class 2 | 515 – 690 MPa (75 – 100 ksi) | 310 MPa (45 ksi) | 18% |
| Gr 9 | Class 1 | 415 – 585 MPa (60 – 85 ksi) | 205 MPa (30 ksi) | 18% |
| Gr 9 | Class 2 | 515 – 690 MPa (75 – 100 ksi) | 310 MPa (45 ksi) | 18% |
| Gr 11 | Class 1 | 415 – 585 MPa (60 – 85 ksi) | 240 MPa (35 ksi) | 22% |
| Gr 11 | Class 2 | 515 – 690 MPa (75 – 100 ksi) | 310 MPa (45 ksi) | 22% |
| Gr 12 | Class 1 | 380 – 550 MPa (55 – 80 ksi) | 230 MPa (33 ksi) | 22% |
| Gr 12 | Class 2 | 450 – 585 MPa (65 – 85 ksi) | 275 MPa (40 ksi) | 22% |
| Gr 22 | Class 1 | 415 – 585 MPa (60 – 85 ksi) | 205 MPa (30 ksi) | 18% |
| Gr 22 | Class 2 | 515 – 690 MPa (75 – 100 ksi) | 310 MPa (45 ksi) | 18% |
| Gr 91 | Class 2 | 585 – 760 MPa (85 – 110 ksi) | 415 MPa (60 ksi) | 18% |
Typical values (for reference)
| Grade | Density (g/cm³) | Modulus of Elasticity (GPa) | Thermal Conductivity (W/m·K) | Thermal Expansion 20–300°C (µm/m·°C) | Typical Max. Service Temp. |
|---|---|---|---|---|---|
| Gr 5 | 7.80 | 205 | 30 | 11.9 | ≈ 650 °C |
| Gr 9 | 7.75 | 205 | 26 | 11.4 | ≈ 650 °C |
| Gr 11 | 7.85 | 205 | 37 | 12.4 | ≈ 595 °C |
| Gr 12 | 7.85 | 205 | 38 | 12.4 | ≈ 565 °C |
| Gr 22 | 7.85 | 205 | 36 | 12.5 | ≈ 600 °C |
| Gr 91 | 7.77 | 218 | 26 | 11.4 | ≈ 650 °C |
Specific heat ≈ 0.46 J/g·°C and melting range ≈ 1450 – 1510 °C for all grades. Allowable temperatures depend on the applicable design code.
Plate thickness (mm) vs theoretical weight (kg/m²)
| Thickness (mm) | ≈ Inch | Weight (kg/m²) | 1500 × 6000 mm (kg) | 2000 × 6000 mm (kg) | 2500 × 12000 mm (kg) |
|---|---|---|---|---|---|
| 3 | 1/8" | 23.55 | 211.95 | 282.60 | 706.50 |
| 5 | 3/16" | 39.25 | 353.25 | 471.00 | 1177.50 |
| 6 | 1/4" | 47.10 | 423.90 | 565.20 | 1413.00 |
| 8 | 5/16" | 62.80 | 565.20 | 753.60 | 1884.00 |
| 10 | 3/8" | 78.50 | 706.50 | 942.00 | 2355.00 |
| 12 | 1/2" | 94.20 | 847.80 | 1130.40 | 2826.00 |
| 16 | 5/8" | 125.60 | 1130.40 | 1507.20 | 3768.00 |
| 20 | 3/4" | 157.00 | 1413.00 | 1884.00 | 4710.00 |
| 25 | 1" | 196.25 | 1766.25 | 2355.00 | 5887.50 |
| 30 | 1 3/16" | 235.50 | 2119.50 | 2826.00 | 7065.00 |
| 40 | 1 9/16" | 314.00 | 2826.00 | 3768.00 | 9420.00 |
| 50 | 2" | 392.50 | 3532.50 | 4710.00 | 11775.00 |
| 60 | 2 3/8" | 471.00 | 4239.00 | 5652.00 | 14130.00 |
| 80 | 3 1/8" | 628.00 | 5652.00 | 7536.00 | 18840.00 |
| 100 | 4" | 785.00 | 7065.00 | 9420.00 | 23550.00 |
| 150 | 6" | 1177.50 | 10597.50 | 14130.00 | 35325.00 |
Weight (kg/m²) = Thickness (mm) × 7.85. Values are theoretical; actual weights vary within ASTM A20 thickness tolerances. Standard plate sizes: 1250 × 2500, 1500 × 3000, 1500 × 6000, 2000 × 6000, 2500 × 6000 and 2500 × 12000 mm. Cut-to-size pieces supplied on request.
Where ASTM A387 alloy steel plates are used
Shells, heads and nozzles of vessels operating at high temperature and pressure.
Boiler drums, headers and waste-heat boiler components.
Shells, channels and tube sheets for high-temperature exchangers.
Hydrocracker, hydrotreater and catalytic reformer reactor vessels.
Process columns, separators and hydrogen-service equipment.
Steam separators, HRSG components and high-temperature ducting.
Quality you can verify on every heat
Large inventory for fast dispatch
MTC EN 10204 3.1 / 3.2
Positive material identification
Pan-India & export shipping
Quick answers about ASTM A387 alloy steel plates
Get competitive pricing, ready stock and complete documentation.
