Stainless Steel, Austenitic1.4305 (303) Bar

A chromium-nickel austenitic stainless steel free machining bar.

Stainless steel type 1.4305 is popularly known as grade 303 stainless steel.

Grade 303 is the most readily machineable of all the austenitic grades of stainless steel.

The machineable nature of grade 303 is due to the presence of sulphur in the steel 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 type 303 is lower than that for 304. The toughness is still excellent as with other austenitic grades.

Property data given in this document is typical for bar products covered by EN Standards. ASTM, or other standards may cover products sold. It is reasonable to expect specifications in these standards to be similar but not necessarily identical to those given in this datasheet.

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Product FormImperial SizesMetric Sizes
Round Bar Bright Drawn H918" - 1"2.0mm - 25.0mm
Round Bar Smooth Turned H9101" - 3"25.0mm - 60.0mm
Round Bar Peeled K12/K163 14" - 8"
Hexagon Bar0.250" - 2.750"7.0mm - 50.0mm
If you do not see what you are looking for, please contact your local service centre with your specific requirements.

Related Specifications

Stainless steel grade 1.4305/334 also corresponds to the following designations but may not be a direct equivalent:

  • UNS S30300
  • BS 303S31
  • EN 58M


Chemical Composition


  • Nuts and bolts
  • Screws
  • Gears
  • Aircraft fittings
  • Bushings
  • Shafts


  • Superior machinability due to the presence of sulphur but with reduced formability
  • Excellent toughness
  • Lower corrosion resistance than 1.4301
  • Poor weldability

Additional Information


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