Steel A387 Gr 5
ASTM A387 Gr 5 · UNS S50200
A387 Grade 5 (S50200, X12CrMo5, 1.7362) is a 5Cr-0.5Mo low-alloy pressure vessel plate whose higher chromium content improves oxidation and sulfidation resistance over the 2.25Cr grades.
Reference datasheet — A387 Gr 5 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 5 tempers and conditions
A387 Gr 5 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, Annealed | Softest, most machinable/formable condition for heads and cold-formed parts that will be re-heat-treated or PWHT'd. | 275 | 480 | 28 | 145 HB | — |
Class 1, Normalized and Tempered | Standard lower-strength class for thick refinery vessel shells where creep/oxidation resistance matters more than room-temperature strength. | 300 | 500 | 26 | 155 HB | — |
CL2-NTDefault Class 2, Normalized and Tempered | Most commonly stocked condition: higher design stress for hydroprocessing reactors, exchanger shells and hot piping. | 380 | 570 | 24 | 180 HB | — |
Class 2, Quenched and Tempered | Chosen for heavy sections (>75 mm) where liquid quenching is needed to meet Class 2 strength and toughness through-thickness. | 420 | 600 | 23 | 14 HRC | — |
What is A387 Gr 5?
A387 Grade 5 (S50200, X12CrMo5, 1.7362) is a 5Cr-0.5Mo low-alloy pressure vessel plate whose higher chromium content improves oxidation and sulfidation resistance over the 2.25Cr grades. It is used for high-temperature refinery vessels and piping components, with 380 MPa yield, 570 MPa tensile, 24 % elongation and about 180 HB (90 HRB) in the normalized-and-tempered condition and service to 620 °C. Machinability and formability are moderate (rated 45 and 40), and welding needs 200–260 °C preheat plus PWHT at 700–760 °C. Grade 9 is the step up when more chromium is required. A387 Gr 5 has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,425°C (2,597 °F). A387 Gr 5 has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 68% of steel grades. Elongation at break is 24% and the elastic modulus is 207 GPa (30 Msi).
What is A387 Gr 5 used for?
- catalytic reformer piping
- high-temperature vessel plate
- sulfidic corrosion service equipment
Advantages
- High service temperature — 620°C (1,148 °F), better than 99% of steel grades
- Good corrosion resistance — 25/100, 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 electrical conductivity — 2.9 % IACS, worse than 93% of steel grades
A387 Gr 5 properties
Typical room-temperature values for A387 Gr 5-CL2-NT; bars are the position among steel grades.
Physical3
A387 Gr 5 has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
A387 Gr 5 has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 68% of steel grades. Elongation at break is 24% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
A387 Gr 5 is rated for continuous service to 620°C (1,148 °F). It conducts heat at 36 W/m·K (20.8 BTU/hr·ft·°F), worse than 73% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical3
A387 Gr 5 conducts electricity at 2.9 % IACS, worse than 93% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), better than 92% of steel grades.
Sustainability4
Producing a kilogram of A387 Gr 5 takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
A387 Gr 5's machinability is fair (45/100, worse than 65% of steel grades); weldability fair (45/100); formability fair (40/100).
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 5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A387 Gr 5
Is A387 Gr 5 easy to machine?
Machines like a medium-hard alloy steel — rigid setups, carbide inserts, 60–110 m/min in the N&T condition; the 5 % Cr makes it more abrasive and gummier than 2.25Cr grades.
Can A387 Gr 5 be welded?
Weld with matching 5Cr-0.5Mo (E502/ER80S-B6) consumables, 200–260 °C preheat/interpass, low-hydrogen practice, and PWHT at 700–760 °C; control P/Sn/Sb for temper-embrittlement resistance.
Can A387 Gr 5 be formed, bent or molded?
Hot form at 900–1050 °C followed by re-normalizing and tempering; cold forming is limited and should be followed by stress relief.
A387 Gr 5 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 |
|---|---|---|
| Cheat analysis, ASTM A387 Gr.5 | ≤ 0.15 | 0.12 |
| Mn | 0.3 – 0.6 | 0.45 |
| Plower P specified for temper-embrittlement control (API 934) | ≤ 0.03 | 0.01 |
| S | ≤ 0.03 | 0.01 |
| Si | ≤ 0.5 | 0.3 |
| Cr | 4 – 6 | 5 |
| Mo | 0.45 – 0.65 | 0.55 |
| Fe | balance |
What surface finishes work on A387 Gr 5?
Not anodizable — protect with high-temperature aluminum/silicone paint, aluminizing or thermal-spray coatings; internal surfaces are often stainless weld-overlay clad.
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 5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S50200
- ASTM
- A387 Grade 5
- Similar grades
- X12CrMo51.7362
How much does A387 Gr 5 cost?
A387 Gr 5 is a standard-cost steel ($$), cheaper than about 71% 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 5 — frequently asked
What is A387 Gr 5 used for?
A387 Gr 5 is typically used for catalytic reformer piping, high-temperature vessel plate and sulfidic corrosion service equipment. In short: 5 % Cr refinery plate; better sulfidation resistance; service to 620 °C.
What is the yield strength of A387 Gr 5?
A387 Gr 5 has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 68% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is A387 Gr 5 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machines like a medium-hard alloy steel — rigid setups, carbide inserts, 60–110 m/min in the N&T condition; the 5 % Cr makes it more abrasive and gummier than 2.25Cr grades.
Can A387 Gr 5 be welded?
With care — weldability is rated fair (45/100). Weld with matching 5Cr-0.5Mo (E502/ER80S-B6) consumables, 200–260 °C preheat/interpass, low-hydrogen practice, and PWHT at 700–760 °C; control P/Sn/Sb for temper-embrittlement resistance.
What surface finishes work on A387 Gr 5?
Not anodizable — protect with high-temperature aluminum/silicone paint, aluminizing or thermal-spray coatings; internal surfaces are often stainless weld-overlay clad.
Can A387 Gr 5 be formed, bent or molded?
Hot form at 900–1050 °C followed by re-normalizing and tempering; cold forming is limited and should be followed by stress relief.
What is the maximum service temperature of A387 Gr 5?
A387 Gr 5 is rated for continuous use to about 620°C (1,148 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A387 Gr 5 CL2-NT and A387 Gr 5 CL1-A?
CL2-NT is the default condition — most commonly stocked condition: higher design stress for hydroprocessing reactors, exchanger shells and hot piping. CL1-A: softest, most machinable/formable condition for heads and cold-formed parts that will be re-heat-treated or PWHT'd. Yield strength is 380 MPa in CL2-NT versus 275 MPa in CL1-A.
How much does A387 Gr 5 cost?
A387 Gr 5 is a standard-cost steel ($$), cheaper than about 71% 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 — Material Properties (5Cr-0.5Mo) — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- API RP 941 — Steels for Hydrogen Service at Elevated Temperatures — API (2016)
- EN 10028-2 / 1.7362 (X12CrMo5) — CEN (2017)
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.