Steel A387 Gr 2
ASTM A387 Gr 2 · UNS S50460
A low-chromium, molybdenum-bearing pressure vessel plate steel offering slightly better elevated-temperature strength than plain carbon-moly plates while remaining economical for medium-temperature service.
Reference datasheet — A387 Gr 2 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the CL2-NT condition
A387 Gr 2 tempers and conditions
A387 Gr 2 is supplied in 4 conditions, soft to hard. CL2-NT is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Class 1 | Softest, most formable condition; pick for heavily cold-formed shells or where only Class 1 strength is needed. | 265 | 440 | 28 | 145 HB | — |
Class 1 | Class 1 strength with refined normalized grain structure — better toughness than annealed at the same low strength level. | 290 | 470 | 26 | 155 HB | — |
CL2-NTDefault Class 2 | The standard stocked condition — higher Class 2 strength for thinner, lighter pressure-vessel shells and heads. | 320 | 500 | 24 | 170 HB | — |
Class 2 | Use for heavy plate where accelerated cooling is needed to meet Class 2 properties and low-temperature Charpy through thickness. | 360 | 530 | 23 | 180 HB | — |
What is A387 Gr 2?
A low-chromium, molybdenum-bearing pressure vessel plate steel offering slightly better elevated-temperature strength than plain carbon-moly plates while remaining economical for medium-temperature service. A387 Gr 2 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F). A387 Gr 2 has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 81% of steel grades. Elongation at break is 24% and the elastic modulus is 205 GPa (29.7 Msi).
What is A387 Gr 2 used for?
- boiler and pressure vessel plate
- steam drums
- process vessel shells
Advantages
- High service temperature — 510°C (950 °F), better than 92% of steel grades
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% of steel grades
Limitations
- Low strength — 320 MPa (46.4 ksi), worse than 81% of steel grades
A387 Gr 2 properties
Typical room-temperature values for A387 Gr 2-CL2-NT; bars are the position among steel grades.
Physical3
A387 Gr 2 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical16
A387 Gr 2 has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 81% of steel grades. Elongation at break is 24% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
A387 Gr 2 is rated for continuous service to 510°C (950 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
A387 Gr 2 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of A387 Gr 2 takes about 29 MJ of energy and emits 2.3 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 25%.
Manufacturability8
A387 Gr 2's machinability is good (55/100, better than 62% of steel grades); weldability good (60/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. A387 Gr 2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A387 Gr 2
Is A387 Gr 2 easy to machine?
Machines like annealed 4130 at roughly 60 % of 1212 — use rigid setups, carbide inserts and moderate speeds; expect stringy chips in the annealed class.
Can A387 Gr 2 be welded?
Readily welded with matching B2/E8018-B2 consumables; preheat 150–200 °C, control interpass, and apply PWHT at 675–705 °C to restore toughness and avoid hard HAZ.
Can A387 Gr 2 be formed, bent or molded?
Hot forming of heads and shells at 900–1000 °C followed by re-normalizing/tempering is standard; cold rolling is possible but limit strains and re-heat-treat if severe.
A387 Gr 2 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C0.05–0.21 for plate ≤ 25 mm; upper limit per A387 Gr 2 | 0.05 – 0.21 | 0.13 |
| Mn | 0.55 – 0.8 | 0.68 |
| P | ≤ 0.04 | 0.01 |
| S | ≤ 0.04 | 0.01 |
| Si | 0.15 – 0.4 | 0.25 |
| Cr | 0.5 – 0.8 | 0.65 |
| Mo | 0.45 – 0.6 | 0.52 |
| Fe | balance |
What surface finishes work on A387 Gr 2?
No anodizing; specify shot blast plus epoxy/silicone-aluminium paint, aluminizing or a stainless/Alloy weld overlay for corrosive process sides.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel A387 Gr 2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S50460
- ASTM
- A387 Grade 2
- Similar grades
- SCMV2
How much does A387 Gr 2 cost?
A387 Gr 2 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
A387 Gr 2 — frequently asked
What is A387 Gr 2 used for?
A387 Gr 2 is typically used for boiler and pressure vessel plate, steam drums and process vessel shells. In short: entry-level chrome-moly plate; economical to 510 °C; readily welded vessel steel.
What is the yield strength of A387 Gr 2?
A387 Gr 2 has a typical yield strength of 320 MPa (46.4 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 81% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is A387 Gr 2 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines like annealed 4130 at roughly 60 % of 1212 — use rigid setups, carbide inserts and moderate speeds; expect stringy chips in the annealed class.
Can A387 Gr 2 be welded?
Yes — weldability is rated good (60/100). Readily welded with matching B2/E8018-B2 consumables; preheat 150–200 °C, control interpass, and apply PWHT at 675–705 °C to restore toughness and avoid hard HAZ.
What surface finishes work on A387 Gr 2?
No anodizing; specify shot blast plus epoxy/silicone-aluminium paint, aluminizing or a stainless/Alloy weld overlay for corrosive process sides.
Can A387 Gr 2 be formed, bent or molded?
Hot forming of heads and shells at 900–1000 °C followed by re-normalizing/tempering is standard; cold rolling is possible but limit strains and re-heat-treat if severe.
What is the maximum service temperature of A387 Gr 2?
A387 Gr 2 is rated for continuous use to about 510°C (950 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A387 Gr 2 CL2-NT and A387 Gr 2 CL1-A?
CL2-NT is the default condition — the standard stocked condition — higher Class 2 strength for thinner, lighter pressure-vessel shells and heads. CL1-A: softest, most formable condition; pick for heavily cold-formed shells or where only Class 1 strength is needed. Yield strength is 320 MPa in CL2-NT versus 265 MPa in CL1-A.
How much does A387 Gr 2 cost?
A387 Gr 2 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A387/A387M — Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum — ASTM International (2021)
- ASME BPVC Section II Part D — Properties (Metric) — ASME (2023)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 6 — Welding, Brazing, and Soldering (Cr-Mo steels) — ASM International (1993)
- API RP 941 — Steels for Hydrogen Service at Elevated Temperatures — API (2016)
- GB/T 713 (15CrMo comparable grade) — SAC (2014)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.