What Is AISI 304 Stainless Steel?

AISI 304 is one of the most common stainless steel grades used in pool equipment manufacturing. Its austenitic structure (roughly 18% chromium, 8% nickel) provides good corrosion resistance under standard pool water conditions — chlorine-disinfected water with low salt content.

It's the preferred choice for nozzles, grilles, ladder bodies and skimmer housings that are constantly in contact with water but not exposed to aggressive chemicals or high salt concentrations. It costs less than AISI 316, making it the economical choice for mid-tier projects.

In saltwater chlorination systems, thermal/spa water, or coastal environments with high chloride exposure, however, AISI 304 is more prone to pitting corrosion over time — AISI 316 should be specified instead in those cases.