303 Stainless Steel Machining

Stainless Steel Alloy 303

Stainless steel alloy 303 is a popular free-machining alloy (FMA), ideal for parts that require extensive machining. It offers good corrosion resistance, withstands heat well, and can be finished to a high polish. 303 is not magnetic.

303 has a machining cost factor of 2.7 when compared to steel 12L14. It can be annealed, but is not as ideal for welding as stainless steel 304. 303 does not respond to heat treatment, but can be cold worked to increase tensile strength and hardness.

Industries & Applications

  • Bolts and nuts
  • Gears
  • Screws
  • Shafts
  • Aircraft components

Stainless Steel 303 Characteristics

TEMPER

Yield Strength

Ultimate Tensile Strength

Modulus of Elasticity

Brinell Hardness (500kg/10mm)

Annealed

35

90

29,000

137

Cold Drawn

61

100

29,000

179

 

Stainless Steel Cost Comparison

Type General Characteristics Alloy Common Applications Tolerances for a 1/2" Dia. Bar Material Cost Factor Machining Cost Factor
Stainless Steel
Designed for machining, non-magnetic
303
Electronic hardware, automotive, aerospace, medical instruments, and many applications requiring corrosion resistance
Cold finished
+/- .002
1.9 2.7

Common Material Cost Comparison

Type General Characteristics Alloy Common Applications Tolerances for a 1/2" Dia. Bar Material Cost Factor Machining Cost Factor
Steel
Designed for excellent machinability. Case hard only
12L14
Endless commercial products; probably more pounds used in turned products than any other bar stock
Cold drawn
0
1 1
Stainless Steel
Designed for machining, non-magnetic
303
Electronic hardware, automotive, aerospace, medical instruments, and many applications requiring corrosion resistance
Cold finished
+/- .002
1.9 2.7
Brass
Strength, corrosion and wear resistance, and excellent machinability
C35300
Well suited for parts with knurling or threading
+0015 3.5 .07
Aluminum
Designed for machining
2011
Electronic hardware, endless commercial products
Cold finish
+/-.0015
3.8 .6
Titanium
High strength, light weight, good bio-compatibility
Ti-6Al-4VEli
Medical implants
Ground & polished
+/-.002
30.2 6

To review our Machining Materials Guide, please click here.

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