Key Feature

The Original "18-8" High-Strength Austenitic Pipe. Higher carbon content (≤0.15%) provides slightly better cold-worked strength than 304, while maintaining excellent corrosion resistance and formability.

The foundational grade offering enhanced strength in cold-worked conditions for specialized applications.

Common Designations

UNS S30200
AISI 302
ASTM A554 (Welded Mechanical Tubing)
EN 1.4310 (often grouped with 301)
JIS SUS302
AMS 5516 (Aerospace)

Historically significant but increasingly replaced by 304 in modern specifications.

Chemical Composition (Typical wt.%)

C: ≤ 0.15
Cr: 17.0 - 19.0
Ni: 8.0 - 10.0
Mn: ≤ 2.00
Si: ≤ 1.00
P: ≤ 0.045
S: ≤ 0.030

Distinguishing feature: Higher carbon than 304 (≤0.15% vs ≤0.08%).

Mechanical Properties (Annealed)

Tensile Strength: ≥ 515 MPa
Yield Strength: ≥ 205 MPa
Elongation: ≥ 40%
Hardness: ≤ 201 HB

Virtually identical to 304 in annealed condition.

Mechanical Properties (Cold Worked)

1/4 Hard: Rm ≥860 MPa, Rp0.2 ≥515 MPa
1/2 Hard: Rm ≥1035 MPa, Rp0.2 ≥760 MPa
3/4 Hard: Rm ≥1210 MPa, Rp0.2 ≥930 MPa
Full Hard: Rm ≥1275 MPa, Rp0.2 ≥965 MPa
Spring Temper: Rm ≥1550 MPa

Slightly higher attainable strengths than 304 due to higher carbon content.

Physical Properties

Density: 7.90 g/cm³
Melting Range: 1399 - 1454 °C
Thermal Expansion: 17.2 × 10⁻⁶/K (20-100°C)
Non-magnetic when annealed

Essentially identical to 304 in all physical properties.

Work Hardening Rate

Moderate work hardening rate between 301 (high) and 304 (lower).

Provides good formability with reasonable strengthening during cold working.

Corrosion Resistance

Excellent general corrosion resistance comparable to 304. Good resistance to atmospheric exposure, fresh water, food products, and many chemicals.

Similar to 304; both perform well in most environments.

Welding Characteristics

Good weldability with standard methods
Possible sensitization in HAZ
304L filler often recommended
Post-weld annealing may be required

Slightly more sensitive to weld decay than 304 due to higher carbon.

Pressure Ratings

Similar to 304 in annealed condition
Higher than 304 in cold-worked tempers
ASME B31.3 compliant

Cold-worked tempers offer improved pressure capabilities.

Key Standards

ASTM A554: Welded Mechanical Tubing
ASTM A632: Seamless & Welded Small Tube
AMS 5516/5517 (Aerospace)
EN 10296-2: Welded Circular Tubes
JIS G3446: Light Gauge Tubes

Still specified in some aerospace and legacy applications.

Common Applications

• Spring Applications: Coil springs, flat springs, spring components in tubular form
• Fastener Systems: Threaded pipe, coupling systems, specialized fittings
• Aerospace: Aircraft structural tubing, hydraulic lines, high-strength components
• Automotive: High-strength structural members, chassis components
• Medical Devices: Surgical instrument frames, specialized equipment
• Industrial Equipment: High-strength machine frames, guard rails
• Consumer Products: High-performance sporting equipment, bicycle frames

Where enhanced cold-worked strength and traditional specifications apply.