SUS430 vs SUS304: Ferritic vs Austenitic Steel Contrast

Chemical & Microstructural Contrast

SUS304 (Austenitic): High Nickel (8-10.5%) + Chromium (18-20%). Face-Centered Cubic (FCC) structure, non-magnetic (unless cold-worked).

SUS430 (Ferritic): No Nickel, lower Chromium (16-18%). Body-Centered Cubic (BCC) structure, magnetic, straight chromium alloy.

Key Property Differences

Corrosion Resistance: 304 is significantly better due to nickel.

Magnetic: 304 is non-magnetic; 430 is magnetic.

Ductility/Formability: 304 is more ductile, easier to draw/form.

Cost: 430 is more cost-effective as it lacks expensive nickel.

Machinability: 430 often offers better machinability for bar products.

Typical Applications

SUS304: Kitchen sinks, food processing, medical equipment, chemical containers, architectural trim.

SUS430: Appliance trim, cutlery, cookware, automotive exhaust, decorative panels.