Stainless Steel 310H
AISI/SAE 310H · UNS S31009
AISI 310H (UNS S31009) is the controlled higher-carbon variant of the 25Cr-20Ni austenitic stainless family, with carbon held up to raise creep and stress-rupture strength for ASME code pressure parts.
Reference datasheet — 310H 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 Annealed condition
310H tempers and conditions
310H is supplied in 6 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Forged + Annealed | Pick for high-temperature flanges, valve bodies and fittings that must match 310H piping in creep strength. | 260 | 590 | 42 | 165 HB | 2.2 % IACS |
Hot Finished Annealed | Pick for large-diameter bar, shafts, hangers and machined furnace fixtures where creep strength matters more than surface finish. | 265 | 600 | 45 | 165 HB | 2.2 % IACS |
AnnealedDefault solution annealed ~1040–1120 °C, rapid cooled (coarse grain for creep) | Standard stocked condition for plate, sheet, bar and pipe; the only condition qualified for ASME elevated-temperature/creep service. | 275 | 620 | 45 | 160 HB | — |
Cold Finished Annealed | Pick for small-diameter machined parts needing tight tolerance and bright surface; strength slightly above hot finished bar. | 310 | 640 | 40 | 180 HB | 2.2 % IACS |
Cold drawn | Pick where higher room-temperature strength or spring-back is wanted (fasteners, wire, mesh); not for creep or long-term high-temperature duty. | 500 | 760 | 25 | 240 HB | — |
Quarter hard | Pick for stiff thin-gauge strip parts (clips, shims, springs) at room to moderate temperature; work-hardened structure recrystallizes above ~600 °C. | 585 | 860 | 15 | 24 HRC | 2.2 % IACS |
Supply forms, finishes and certifications
Ways 310H is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Tube-Ann | Tube/Pipe Annealed | Supply form |
2B | Cold rolled, annealed, pickled and lightly skin-passed sheet | Surface finish |
HRAP | Hot rolled, solution annealed and pickled plate | Surface finish |
What is 310H?
AISI 310H (UNS S31009) is the controlled higher-carbon variant of the 25Cr-20Ni austenitic stainless family, with carbon held up to raise creep and stress-rupture strength for ASME code pressure parts. Annealed properties are about 275 MPa yield, 620 MPa tensile, 45 % elongation and 160 HB, with service to 1100 °C; forms include annealed sheet and plate, HRAP, 2B, cold-drawn bar, 1/4H strip and annealed tube. Machinability is low and the higher carbon makes long exposure sensitization-prone; choose 310Cb or 310HCb where intergranular attack matters, or 310S for lower-stress oxidation service. 310H has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 85% of stainless steel grades. It melts at 1,400°C (2,552 °F). 310H has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 77% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi).
What is 310H used for?
- high-temperature pressure vessels
- petrochemical furnace tubing
- power boiler components
Advantages
- High service temperature — 1,100°C (2,012 °F), better than 96% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
- Forms and bends easily — 68/100, better than 75% of stainless steel grades
Limitations
- High embodied carbon — 5.8 kg CO₂/kg, worse than 86% of stainless steel grades
- Low strength — 275 MPa (39.9 ksi), worse than 77% of stainless steel grades
310H properties
Typical room-temperature values for 310H-Annealed; bars are the position among stainless steel grades.
Physical3
310H has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 85% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical14
310H has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 77% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
310H is rated for continuous service to 1,100°C (2,012 °F). It conducts heat at 14.2 W/m·K (8.2 BTU/hr·ft·°F), worse than 76% of stainless steel grades. Thermal expansion is 15.9 µm/m·K (8.83 µin/in·°F).
Electrical3
310H conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 52% of stainless steel grades.
Sustainability4
Producing a kilogram of 310H takes about 85 MJ of energy and emits 5.8 kg of CO₂ — more than 92% of stainless steel grades. Typical recycled content is 55%.
Manufacturability7
310H's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability very good (70/100); formability good (68/100).
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 stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 310H is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 310H
Is 310H easy to machine?
Gummy and strongly work-hardening: use rigid setups, positive-rake sharp carbide, 25–50 % lower surface speed than 304, heavy feed to stay under the hardened skin, and copious high-lubricity coolant.
Can 310H be welded?
Weld with matching 310/25-20 filler (ER310/E310-15) using low heat input, stringer beads and interpass temperature below ~150 °C; fully austenitic weld metal is hot-crack sensitive and no post-weld heat treatment is normally needed, but re-solution treatment restores creep properties after heavy fabrication.
Can 310H be formed, bent or molded?
Cold forms well but needs ~50 % higher press loads and generous bend radii due to the high work-hardening rate; hot work at 1150–1200 °C and finish above 950 °C, then solution anneal at 1040–1120 °C with rapid cooling to avoid sigma/carbide networks.
310H 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 |
|---|---|---|
| Ccontrolled higher carbon — source of the improved creep strength vs 310S | 0.04 – 0.1 | 0.07 |
| Cr | 24 – 26 | 25 |
| Ni | 19 – 22 | 20.5 |
| Mn | ≤ 2 | 1.5 |
| SiSi aids oxidation resistance | ≤ 1.5 | 0.6 |
| P | ≤ 0.05 | 0.03 |
| S | ≤ 0.03 | 0.01 |
| Febalance ≈ 50 % | balance | — |
What surface finishes work on 310H?
Pickle and passivate (HNO3-based) or electropolish after fabrication to restore the chromium oxide film; not anodizable — for high-temperature service leave bare, and grind/blast media must be iron-free to avoid contamination.
Surface treatments FabDigit runs on stainless 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).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 310H in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S31009
How much does 310H cost?
310H is a premium-cost stainless steel ($$$), cheaper than about 51% 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.
310H — frequently asked
What is 310H used for?
310H is typically used for high-temperature pressure vessels, petrochemical furnace tubing and power boiler components. In short: creep-rated 310 for ASME; higher-carbon 310 variant; code pressure-part stainless.
What is the yield strength of 310H?
310H has a typical yield strength of 275 MPa (39.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 77% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 310H easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% of stainless steel grades). Gummy and strongly work-hardening: use rigid setups, positive-rake sharp carbide, 25–50 % lower surface speed than 304, heavy feed to stay under the hardened skin, and copious high-lubricity coolant.
Can 310H be welded?
Yes — weldability is rated very good (70/100). Weld with matching 310/25-20 filler (ER310/E310-15) using low heat input, stringer beads and interpass temperature below ~150 °C; fully austenitic weld metal is hot-crack sensitive and no post-weld heat treatment is normally needed, but re-solution treatment restores creep properties after heavy fabrication.
What surface finishes work on 310H?
Pickle and passivate (HNO3-based) or electropolish after fabrication to restore the chromium oxide film; not anodizable — for high-temperature service leave bare, and grind/blast media must be iron-free to avoid contamination.
Can 310H be formed, bent or molded?
Cold forms well but needs ~50 % higher press loads and generous bend radii due to the high work-hardening rate; hot work at 1150–1200 °C and finish above 950 °C, then solution anneal at 1040–1120 °C with rapid cooling to avoid sigma/carbide networks.
What is the maximum service temperature of 310H?
310H is rated for continuous use to about 1,100°C (2,012 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 310H Annealed and 310H-CD?
Annealed is the default condition — standard stocked condition for plate, sheet, bar and pipe; the only condition qualified for ASME elevated-temperature/creep service. CD: pick where higher room-temperature strength or spring-back is wanted (fasteners, wire, mesh); not for creep or long-term high-temperature duty. Yield strength is 275 MPa in Annealed versus 500 MPa in CD.
How much does 310H cost?
310H is a premium-cost stainless steel ($$$), cheaper than about 51% 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 A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip — ASTM International (2023)
- ASTM A213/A213M — Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes — ASTM International (2022)
- ASTM A479/A479M and A182/A182M — Stainless Bars and Forgings for Pressure Vessels/Piping — ASTM International (2022)
- ASME BPVC Section II Part D — Properties (Metric), allowable stresses for S31009 — ASME (2023)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Heat-resisting austenitic stainless 310S/310H product data — Outokumpu / Sandvik (2022)
- GB/T 24511 / GB/T 1220 06Cr25Ni20 (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.