304 vs 316L: when the price gap is worth paying
Chloride exposure, welding, hygiene requirements and lifecycle cost decide whether 316L is mandatory.
316L contains 2-3% molybdenum, which gives it clearly better resistance to pitting and crevice corrosion than 304. The price premium is typically 15-30%. Choose 316L when: the service environment contains chlorides (coastal atmosphere, seawater, chloride-based cleaning agents), welded joints cannot be fully solution annealed, sanitary service in food or pharmaceutical plants is required, or maintenance access is difficult. 304 remains adequate for dry indoor environments, chloride-free media, and cost-sensitive decorative or structural parts. Decide by quantifying chloride concentration and temperature, checking whether welds and crevices exist, and comparing ten-year maintenance cost rather than price per tonne.