Grade overview

The Cr-Ni-Mo alloy system improves chloride resistance, though 316 is not immune to chloride pitting or stress-corrosion cracking.

Typical applications

Chemical equipment, marine-adjacent service, food/pharma systems, heat exchangers, architectural components and process piping.

Equivalent / related designations

EN 1.4401 and JIS SUS316 are commonly compared. Suitability depends on chloride level, temperature, surface condition and crevice geometry.

Common manufacturers and supply

Produced by major stainless mills including Outokumpu, Acerinox, Aperam, POSCO, Jindal Stainless, Tsingshan and TISCO/Baowu.

Fabrication and selection notes

Confirm the exact product standard, edition, dimensions, delivery condition, mechanical properties, impact requirements, heat treatment, welding procedure, corrosion environment and certification. A grade name alone is not sufficient for procurement or design approval.

QA/QC documentation

316 versus 316L: why the suffix matters

316L is the low-carbon counterpart of 316. Lower carbon content can help reduce sensitization concerns in welded fabrications, but does not make the alloy immune to chloride pitting, crevice corrosion or stress-corrosion cracking. Dual-certified 316/316L material may be available, subject to the ordered specification and test certificate. The final choice must follow the relevant design and welding requirements.

Typical chemistry and designations

Common nominal alloying ranges for 316 include approximately 16–18% chromium, 10–14% nickel and 2–3% molybdenum, with limits defined by the governing product specification. UNS S31600 and EN 1.4401 are widely used related designations; UNS S31603 and EN 1.4404 refer to low-carbon 316L. Cross-standard equivalence must be verified, not assumed.

Practical corrosion checklist

• Record chloride concentration, operating temperature and possible concentration during evaporation.
• Identify crevices under gaskets, deposits, clamps and stagnant sections.
• Consider surface finish, pickling/passivation and weld heat tint removal where specified.
• For seawater or high-chloride service, evaluate duplex stainless, higher-alloy grades or other materials rather than automatically selecting 316.

For critical service, verify heat number traceability, mill test certificate, chemical analysis, tensile/impact results where required, NDT, heat-treatment record and project-specific third-party inspection requirements.

Element Folio engineering reference. Values and requirements vary by standard edition, product form and manufacturer; always verify the latest governing specification.