stainless steel SUS303 vs SUS304: Free-Cutting vs Standard 18-8 Stainless — When to Choose Which
SUS303 machines 35% faster than SUS304 but cannot be welded and corrodes faster. SUS304 welds cleanly and withstands chloride environments. This guide breaks down the composition difference, machinability mechanism, corrosion gap, weldability prohibition, and gives an exact decision rule for every common application.