AISI 310/310S Stainless Steel: Composition and Properties
Aug 21, 2025
Leave a message
What Is AISI 310 Stainless Steel
AISI 310 (UNS S31000) is a high-chromium, high-nickel austenitic stainless steel with a maximum carbon content of 0.25%. It offers excellent mechanical properties, oxidation resistance and heat resistance at elevated temperatures. The family includes 310S (UNS S31008), the low-carbon variant with 0.08% maximum carbon; 310H (UNS S31009), with carbon controlled at 0.04-0.10% to obtain the best creep and creep-rupture strength; and 310Cb (UNS S31040), stabilized with niobium to prevent sensitization and improve weldability and high-temperature creep strength.
Chemical Composition
Composition limits per ASTM A240/A240M for plate, sheet and strip and per ASTM A276/A276M for bar.
| Element (wt %) | 310 (S31000) | 310S (S31008) | 310H (S31009) | 310Cb (S31040) |
|---|---|---|---|---|
| Carbon, max | 0.25 | 0.08 | 0.04-0.10 | 0.08 |
| Manganese, max | 2.00 | 2.00 | 2.00 | 2.00 |
| Phosphorus, max | 0.045 | 0.045 | 0.045 | 0.045 |
| Sulfur, max | 0.03 | 0.03 | 0.03 | 0.03 |
| Silicon, max | 1.50 | 1.50 | 0.75 | 1.50 |
| Chromium | 24.0-26.0 | 24.0-26.0 | 24.0-26.0 | 24.0-26.0 |
| Nickel | 19.0-22.0 | 19.0-22.0 | 19.0-22.0 | 19.0-22.0 |
| Niobium | - | - | - | 10 x C to 1.10 |
Mechanical Properties
Annealed plate values per ASTM A240/A240M for 310S, 310H, 310Cb and 310HCb: tensile strength 515 MPa (75 ksi) min, 0.2% yield strength 205 MPa (30 ksi) min, elongation 40% min in 2 in (50 mm), Brinell hardness 217 HB max and Rockwell 95 HRB max. Bar products per ASTM A276/A276M in the annealed hot-finished condition for all diameters require 515 MPa (75 ksi) tensile, 205 MPa (30 ksi) yield, 40% elongation and 50% reduction of area; annealed cold-finished bar up to 12.7 mm (1/2 in) diameter requires 620 MPa (90 ksi) tensile and 310 MPa (45 ksi) yield.
| Property (min) | Plate, ASTM A240 | Bar, ASTM A276 |
|---|---|---|
| Tensile strength (MPa / ksi) | 515 / 75 | 515 / 75 |
| 0.2% yield strength (MPa / ksi) | 205 / 30 | 205 / 30 |
| Elongation in 2 in (50 mm), % | 40 | 40 |
| Reduction of area, % | - | 50 |
High-Temperature Performance
Grade 310/310S maintains a stable chromium oxide scale in air, with a maximum intermittent service temperature of 1035°C (1895°F) and a maximum continuous service temperature of 1150°C (2100°F). These grades are therefore used for furnace components, heat exchangers and industrial ovens. Resistance to chloride-induced pitting is weaker than molybdenum-bearing grades such as 316, so 310 should not be selected primarily for chloride corrosion service. Where design is governed by creep strength, 310H is specified; where sensitization during welding is a concern, 310S or the niobium-stabilized 310Cb is preferred.
310 vs 310S: Selection Guidance
The specified difference between 310 and 310S is carbon content: 0.25% max versus 0.08% max. The higher-carbon 310 offers marginally higher strength at high temperature but is more prone to chromium carbide precipitation during welding. 310S is the preferred choice for welded constructions and for service where intergranular corrosion resistance is required, because the lower carbon content improves weldability and reduces the risk of sensitization. For parts operating continuously above about 900°C where creep resistance dominates the design, the controlled-carbon 310H grade is the appropriate selection.
Frequently Asked Questions
Q1. What is the difference between 310 and 310S?
Carbon content: 310 has 0.25% max carbon and 310S has 0.08% max, which improves weldability and resistance to sensitization.
Q2. What is 310H used for?
310H (0.04-0.10% carbon) is specified for components designed on creep and creep-rupture strength, such as petrochemical furnace tubes.
Q3. What is the maximum service temperature of 310/310S in air?
1035°C (1895°F) for intermittent service and 1150°C (2100°F) for continuous service.
Q4. Is 310 magnetic?
The grade is austenitic and essentially non-magnetic in the annealed condition.
Q5. Can 310 be welded?
Yes, by common austenitic stainless steel processes; 310S is preferred for heavy weldments to avoid sensitization.
Q6. Which standards cover 310 plate and bar?
Plate, sheet and strip per ASTM A240/A240M; bar per ASTM A276/A276M; related EN designation 1.4845 for the low-carbon version.
Send Inquiry