304 vs 316 stainless: which one do you need?

October 16, 2026  ·  Indumor

316 is not "better" than 304. It is different.

Both belong to the austenitic 18/8 family that has dominated stainless for a century — 304 was born in the 1920s as the "universal" stainless, and 316 came later for one specific enemy 304 could not beat: chloride. That history explains everything that follows.

The technical difference: 2% molybdenum

316 adds molybdenum to the recipe. That 2% makes it far more resistant to the pitting corrosion caused by chlorides: salt, brines, chlorinated sanitizers, marine air. For everything else — mild acids, fresh water, dry foods — they behave almost identically.

When 304 is plenty

The vast majority of cases: worktables, sanitary structures, water tanks, food service equipment, dairy, brewing, mild chemical service. If your process has no chlorides and no salt air, 304 is more than enough and your budget will thank you: 316 typically costs 20-40% more.

When 316 is mandatory

Meat and fish plants running brine. Facilities sanitizing daily with hypochlorite. Coastal and marine environments. Chloride chemistry. Demanding pharma. There, 304 pits within months and the "saving" ends in premature replacement — cheap turns expensive, metallurgical edition.

The classic mistake: mixing grades silently

A plant specifies 316 and someone "completes" the job with 304 bolts or fittings: two years later, the pitted spots mark exactly where the saving happened. The spec gets honored completely, fasteners included.

To go deeper

How we work sanitary stainless: stainless for the food industry. What to use when stainless is not required: carbon, stainless or galvanized. And our tanks and vessels service, where this decision gets made on every project.

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