Stainless Steel 303

Material Data Sheet

The machineable nature of Grade 303 stainless steel is due to the presence of Sulphur in the steels composition. Whilst the Sulphur improves machining, it also causes a decrease in the corrosion resistance and a slight lowering of the toughness. The corrosion resistance of grade 303 stainless steel is lower than that for 304. The toughness is still excellent as with other austenitic grades.

Chemical Composition
Element Content(%)
Iron, Fe 69.00
Chromium, Cr 18.00
Nickel, Ni 9.00
Manganese, Mn ≤2.00
Silicon, Si ≤1.00
Carbon, C ≤0.15
Phosphorus, P ≤0.20
Sulfur, S ≤0.35
Physical Properties
Properties Metric Imperial
Density 7.89 g/cc 0.290 lb/in3
Melting Point 1400 – 1420 °C 2550 – 2590 °F
Mechanical Properties
Properties Metric Imperial
Hardness, Brinell 228 228
Hardness, Knoop 251 251
Hardness, Rockwell B 96 96
Hardness, Rockwell C 19 19
Hardness, Vickers 240 240
Tensile Strength, Ultimate 690 MPa 100000 psi
Tensile Strength, Yield 415 MPa 60200 psi
Elongation at Break 40% 40%
Modulus of Elasticity 193 GPa 28000 ksi
Poisson’s Ratio 0.25 0.25
Fatigue Strength 240 MPa 34800 psi
Shear Modulus 77.2 GPa 11200 ksi
Thermal Properties
Properties Metric Imperial
CTE, linear 20°C 17.2 µm/m-°C 9.56 µin/in-°F
Specific Heat Capacity 0.5 J/g-°C 0.12 BTU/lb-°F
Thermal Conductivity 16.2 W/m-K 112 BTU-in/hr-ft²-°F
Applications

Stainless Steel 303 is used in the following application areas:

  • Aircraft applications including fittings, shafts and spindles
  • Automatic screw machine applications
  • Medical devices with screw threads, drilled or tapped holes
  • Pump and valve parts
  • Architectural applications
  • Nuts and bolts

Key Words: T303, T 303, 303SS, 303 SS, AFNOR Z 10 CNF 18.09 (Fr), UNI X 10 CrNiS 18 09, SUS 303, SS14 2346 (Sweden), B.S. 303 S 21, UNS S30300, AMS 5640 (1), ASME SA194, ASME SA320, ASTM A194, ASTM A314, ASTM A320, ASTM A320, ASTM A473, ASTM A581, ASTM A582, MIL SPEC MIL-S-862, SAE J405 (30303), DIN 1.4305, X12CrNiS188, EN 58M, austenitic, ISO 683/13 17, 18-8

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