Stainless 304
AKA: SS304 / 1.4301
General stainlessPassivate OKNo anodize
General-purpose stainless; passivate/polish — not anodize.
Material family
Stainless
304 / 316 / 303 / 17-4PH — passivate/polish, never anodize.
4 quote-ready grades
Stainless 316
AKA: SS316 / better corrosion resistance
Better corrosion resistanceMedical/lab commonPassivate OK
Better corrosion resistance than 304; common in medical/lab hardware.
Stainless 303
AKA: SS303 / free-machining
Free-machiningVolume small partsTurn/mill friendly
Free-machining stainless for turned/milled volume small parts.
17-4PH stainless
AKA: 17-4PH / 1.4542
Precipitation hardeningHigh strengthCall out temper
Precipitation-hardening stainless; call out heat-treat condition on drawings.