SS 304 vs SS 316

Both are austenitic stainless steels. 316 contains molybdenum, typically around 2 to 3 per cent, which markedly improves resistance to chlorides — salt, and some cleaning chemicals. Everything else about them, including appearance, finish behaviour and fabrication, is broadly similar.

Dry interiors, most commercial and residential work, ceilings, profiles, trims, lift interiors, furniture. This is the overwhelming majority of architectural metalwork, and 304 is not a compromise in those positions — it is the correct specification.

Coastal and marine exposure, swimming pool halls, spa and wet areas, food processing, external work in polluted urban environments, and anywhere subject to aggressive cleaning regimes.

316 costs meaningfully more. Specifying it throughout a dry interior project is money that would usually do more good elsewhere in the detail — a better finish, a deeper section, a physical mock-up. Specify it where the environment actually demands it.

PVD coating works on both grades. The coating does not replace the corrosion resistance of the substrate, so an aggressive environment still calls for 316 underneath.