430 (1.4016, about 16% Cr) and 304 (1.4301, 18% Cr + 8% Ni) are the two grades most often compared.

Main differences:

• Structure: 430 is ferritic and magnetic; 304 is austenitic and normally non-magnetic (it may pick up slight magnetism after cold working). • Corrosion: the Cr-Ni combination of 304 is clearly more stable in wet or chloride-containing environments. 430 works in dry indoor or general decorative settings, but not for long-term wet, coastal or wet food-processing areas. • Forming: 430 has lower ductility and is prone to cracking in deep drawing; 304 forms and bends more easily. • Cost: 430 contains no nickel, so it is usually cheaper and less volatile.

Guidance:

1) Indoor decoration, dry enclosures and some appliance panels: 430 offers good value. 2) Kitchenware in contact with water and food, coastal buildings and deep-drawn parts: prefer 304. 3) Welded structures: 430 welds less well than 304 and loses toughness in the heat-affected zone — proceed carefully.

Specify the service environment (wet, salty, deep-drawn) rather than choosing on grade price alone.