Stainless Steel / 303 SULF ANN

303 SUL is an austenitic stainless steel melted as AOD melt type and offers excellent machinability. The machinable nature of Grade 303 stainless steel is due to the presence of Sulphur in the steel's composition. The Sulphur improves machining and provides non- seizing properties, but 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. 303 is a 18-8 chromium-nickel stainless steel that is non-magnetic in the annealed condition and not hardenable by heat treatment. Stainless Steel 303 is widely used in the screw machine industry, as well as for use in shafts, valves and fittings. Stainless Steel 303 is not recommended for vessels containing gases or liquids under high pressure. (UNS:S30323)

Chemical Makeup

Element Min Max
Carbon, C 0.15
Manganese, Mn 2
Silicon, Si 1
Sulfur, S 0.15 -
Phosphorus, P - 0.15
Chromium, Cr 17 19
Nickel, Ni 8 10
Copper, Cu - 1
Molybdenum, Mo - 1
Selenium, Se - -

Common Applications

  • Aerospace Aerospace
  • Industrial Industrial


  • Excellent Machinability
  • Corrosion Resistance
  • Nongalling Properties

We stock 303 SULF ANN to the following specifications:

  • AMS-5640 TYPE 1
  • ASTM-A-320 GRD B8F CL.1 (EXC. FLTS)
  • ASTM-A-484
  • ASTM-A-582
  • MIL-S-7720
  • MIL-W-52263
  • QQS-763C
  • QQS-764 B

Click on a cross-section to see the sizes we stock:

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