Stainless Steel T-303 (UNS S 30300) 18-8 Chromium- Nickel Freemachining Stainless Steel Available mainly in wire and bar form to ASTM A581 and A582
Typical Analysis
C Mn P S Si Cr Ni Mo
.15Max 2.0Max .20Max .15Min 1.0Max 17/19 8/10 .60Opt.
  • A sulphur-bearing chromium-nickel austenitic steel, this grade offers excellent machinability, non-galling properties and good corrosion resistance. It is non-magnetic in the annealed condition and is not hardenable by heat treatment. However, tensile strength and hardness can be increased by cold working. Welding is not recommended for T-03, but if necessary use T-308 electrodes and the welds must be annealed. Machinability is rated at 60% - 100 surface feet per minute
Typical Applications
  • Used almost exclusively for parts requiring machining and primarily in automatic screw machines. Bushings, fittings, shafts, valves, bolts and nuts.
Corrosion and Heat Resistance
  • T-303 has slightly less general corrosion resistance than T-302/T-304 due to the sulphur content. It has good resistance to scaling up to 870℃ in continuous service and to 760℃ in intermittent service
Stainless Steel T-303 (UNS S 30300) Mechanical Properties - T-303 Bar sizes – Typical
  • Please note that ASTM A582 does not specify detailed mechanical properties (as above) except that the hardness shall not exceed HB 262. Accordingly mill test certificates will not usually show these details
Spec H.R. Ann Ann & CF
Tensile Strength, psi 90,000 100,000
Tensile Strength, N/mm² 620 690
Yield Strength, psi 35,000 60,000
Yield Strength, N/mm² 241 414
Elongation (%) 50 40
Reduction of Area (%) 55 50
Hardness 163 229
Stainless Steel T-303 (UNS S 30300) Mechanical Properties - T-303 Wire Sizes
  • ASTM A581 specifies tensile strength as follows
Spec Cond. ‘A’ – Annealed Cond. ‘B’ – Cold Worked
Tensile Strength, psi 85,000/125,000 115,000/145,000
Tensile Strength, N/mm² 590/860 790/1000

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