Overview
303 adds sulfur to the 18/8 chemistry so chips break cleanly, making it the easiest austenitic stainless to machine — ideal for turned parts in volume.
The sulfur slightly lowers corrosion resistance and weldability compared with 304.
Key Properties
Typical values from the MatWeb datasheet for 303 Stainless Steel, annealed. Machined parts take the properties of the stock they are cut from.
| Property | Value |
|---|---|
| Density | 8.00 g/cm³ |
| Tensile strength | 620 MPa |
| Yield strength | 240 MPa |
| Elongation at break | 50 % |
| Modulus of elasticity | 193 GPa |
| Thermal conductivity | 16.2 W/m-K |
| Melting range | 1400–1420 °C |
| Magnetic permeability | 1.008 |
Typical Applications
- Shafts, pins and bushings
- Fasteners and fittings
- Valve and pump parts
- Screw-machine parts
Machining Notes
Not recommended for welding or for marine and chloride exposure — use 316 there.
