Grade 303 stainless steel,ss 303 steel

Grade 303 stainless steel 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.

Grade 303 stainless steel Chemical Element % Present
Carbon (C) 0.0 - 0.10
Chromium (Cr) 17.00 - 19.00
Manganese (Mn) 0.0 - 2.00
Silicon (Si) 0.0 - 1.00
Phosphorous (P) 0.0 - 0.45
Sulphur (S) 0.0 - 0.15
Nickel (Ni) 8.00 - 10.00
Iron (Fe) Balance

303 stainless steel Physical Property Value
Density 8.03 g/cm³
Melting Point 1455 °C
Thermal Expansion 17.3 x10^-6 /K
Modulus of Elasticity 193 GPa
Thermal Conductivity 16.3 W/m.K
Electrical Resistivity 0.072 x10^-6 Ω .m

ss 303 steel has good resistance to oxidation when intermittently exposed to temperature up to 760°C temperatures. It also has good oxidation resistance in continuous service to 870°C. This, however, is not recommended as 303 is sensitive to carbide precipitation with continuous use at 425-860°C.