Key Feature

The High-Strength Work-Hardening Austenitic Bar Stock. Unique ability to develop exceptional strength (up to 1500+ MPa) through cold working alone, enabling high-strength applications without heat treatment.

The highest strength potential among standard austenitic stainless steel bars through cold working.

Common Designations

UNS S30100
AISI 301
ASTM A276 (Stainless Steel Bars)
ASTM A479 (Bars for Pressure Vessels)
EN 1.4310, X10CrNi18-8
JIS SUS301

Often specified by temper condition (annealed, 1/4H, 1/2H, 3/4H, full hard).

Chemical Composition (Typical wt.%)

C: ≤ 0.15
Cr: 16.0 - 18.0
Ni: 6.0 - 8.0Mn: ≤ 2.00
Si: ≤ 1.00
P: ≤ 0.045
S: ≤ 0.030

Lower nickel than 304 (6-8% vs 8-10.5%) enables strain-induced martensite formation.

Mechanical Properties by Temper

Annealed: Rm ≥515 MPa, Rp0.2 ≥205 MPa, A ≥40%
1/4 Hard: Rm ≥860 MPa, Rp0.2 ≥515 MPa, A ≥25%
1/2 Hard: Rm ≥1035 MPa, Rp0.2 ≥760 MPa, A ≥18%
3/4 Hard: Rm ≥1210 MPa, Rp0.2 ≥930 MPa, A ≥12%
Full Hard: Rm ≥1275 MPa, Rp0.2 ≥965 MPa, A ≥9%

Strength increases dramatically with cold work; ductility decreases correspondingly.

Physical Properties

Density: 7.90 g/cm³
Melting Range: 1399 - 1454 °C
Thermal Expansion: 17.0 × 10⁻⁶/K (20-100°C)
Thermal Conductivity: 16.3 W/m·K (100°C)
Magnetic Response: Becomes magnetic when cold worked

Transformation to martensite during cold working induces magnetism.

Work Hardening Mechanism

Strain-induced transformation of austenite to martensite during cold working. Rate depends on temperature, strain rate, and initial condition.

Unique among 300-series stainless steels; enables extraordinary strengthening.

Available Forms

Rounds: 6mm - 150mm diameter
Squares: 6mm - 75mm
Flats: Various sizes
Hexagons: 6mm - 50mm
Angles: Structural angles
Wire: For spring applications

Full range of bar forms, with emphasis on smaller sizes for forming applications.

Surface Conditions

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

Various finishes available; cold drawn most common for work-hardening applications.

Corrosion Resistance

Good general corrosion resistance similar to 304 in annealed condition. May decrease slightly in heavily cold-worked areas due to martensite formation.

Suitable for most atmospheric and mild chemical environments; not for severe chloride exposure.

Machining Characteristics

• Varies significantly with temper• Annealed: Good machinability
• Hard tempers: Difficult to machine
• Higher tool wear in hard tempers
• Best machined before cold working

Typically formed or used as-supplied; machining often done before final cold working.

Key Standards

ASTM A276 301: Stainless Steel Bars
ASTM A479 301: Bars for Pressure Vessels
ASTM A484: General Requirements
EN 10088-3: Stainless Steel Bars
JIS G4303: Stainless Steel Bars
AMS 5519 (Aerospace)

Typically specified by both grade and temper condition.

Common Applications

• Spring Applications: Coil springs, flat springs, spring clips, retainer rings
• Aerospace Components: Aircraft structural parts, fasteners, high-strength fittings
• Automotive: High-strength brackets, clips, structural components
• Electronics: Connector contacts, springs, shielding components
• Industrial Equipment: High-strength machine parts, conveyor components
• Rail Transportation: Carriage components, structural clips, fasteners
• Consumer Products: High-performance sporting equipment, bicycle components

Specifically selected where high strength and formability are required.