Key Feature

The Premium High-Temperature Austenitic Stainless Steel Bar Stock. Exceptionally high chromium and nickel content provides outstanding oxidation resistance and strength at temperatures up to 1150°C for high-temperature applications.

The standard material for high-temperature furnace components and heat-resistant bar applications.

Common Designations

UNS S31008
AISI 310S
ASTM A276 (Stainless Steel Bars)
ASTM A479 (Bars for Pressure Vessels)
EN 1.4845, X8CrNi25-21
JIS SUS310S

"S" indicates low carbon version; standard 310 has higher carbon (≤0.25%).

Chemical Composition (Typical wt.%)

C: ≤ 0.08
Cr: 24.0 - 26.0Ni: 19.0 - 22.0Mn: ≤ 2.00
Si: ≤ 1.50
P: ≤ 0.045
S: ≤ 0.030

High Cr provides oxidation resistance; high Ni ensures austenite stability at high temperatures.

Mechanical Properties

Tensile Strength: ≥ 515 MPa
Yield Strength: ≥ 205 MPa
Elongation: ≥ 40%
Hardness: ≤ 217 HB
Machinability: 35% of B1112 steel

Good room-temperature properties, but designed for elevated temperature performance.

Elevated Temperature Properties

Continuous Service: Up to 1150°C
Intermittent Service: Up to 1100°C
Creep Strength: Excellent up to 1000°C
Oxidation Resistance: Excellent up to 1100°C

Superior to 304/316 grades above 800°C; maintains strength better at high temperatures.

Physical Properties

Density: 7.98 g/cm³
Melting Range: 1400 - 1450 °C
Thermal Expansion: 15.9 × 10⁻⁶/K (20-100°C)
Thermal Conductivity: 14.2 W/m·K (100°C)
Non-magnetic when annealed

Higher density than 304; thermal expansion similar to other austenitics.

Available Forms

Rounds: 6mm - 250mm diameter
Squares: 6mm - 125mm
Hexagons: 6mm - 100mm
Flats: Various sizes
Billets: For forging applications
Forgings: Custom forged components

Available in sizes suitable for high-temperature component manufacturing.

Surface Conditions

Hot Rolled: As-rolled surface
Cold Drawn: Bright finish
Centerless Ground: Precision ground
Polished: For specific applications
Peeled: Improved surface for machining

Various surface finishes for different application requirements.

Corrosion Resistance

Excellent oxidation resistance at high temperatures. Good general corrosion resistance similar to 304 at room temperature. Not designed for chloride-rich environments.

High chromium provides good corrosion resistance, but limited chloride resistance.

Machining Characteristics

• Difficult to machine due to high strength/work hardening
• High tool wear• Requires rigid setups• Good chip control with proper techniques
• Surface finish achievable

One of the more challenging austenitic grades to machine due to high alloy content.

Welding Characteristics

Good weldability with standard methods
310S preferred over 310 for welding
Possible sigma phase formationPost-weld solution annealing recommended

Must control heat input and cooling rate to prevent embrittlement.

High-Temperature Strength Retention

At 800°C: ~30% of room temp strength
At 900°C: ~20% of room temp strength
At 1000°C: ~10% of room temp strength

Better high-temperature strength retention than lower-alloy grades.

Key Standards

ASTM A276 310S: Stainless Steel Bars
ASTM A479 310S: Bars for Pressure Vessels
ASTM A484: General Requirements
EN 10088-3: Stainless Steel Bars
JIS G4303: Stainless Steel Bars
ASME SA479: Code Construction

Comprehensive standardization for quality assurance.

Common Applications

• Furnace Components: Radiant tubes, retorts, muffles, furnace rails, hangers
• Heat Treatment Fixtures: Baskets, trays, fixtures, hangers, supports
• Thermal Processing: Kiln furniture, pyrolysis components, calciner parts
• Power Generation: Superheater supports, boiler components, high-temperature fasteners
• Chemical Processing: High-temperature reactor parts, reformer components, pyrolysis tubes
• Aerospace: Afterburner components, exhaust system parts, high-temperature fasteners
• Glass Manufacturing: Mold components, handling equipment, support structures

Specifically designed for continuous high-temperature operation in bar form.