Specify by what the material has to survive.

The default austenitic stainless. 18% chromium, 8% nickel, no molybdenum.

304 plus 2–3% molybdenum. The standard answer to chlorides and mild acids.

Higher molybdenum than 316, at 3–4%. The step up before super-austenitics.

304 stabilised with titanium. Resists sensitisation in the 425–815 degrees C range.

Stabilised with niobium rather than titanium. Preferred where weld filler purity matters.

25% chromium, 20% nickel. A heat-resisting grade, not a corrosion-resisting one.

304 with sulphur added for machinability. The free-machining austenitic.

Chromium-manganese-nickel austenitic grade. A lower-cost alternative to 304 for dry, indoor and decorative use.

Manganese and nitrogen substitute for nickel. A cost-driven austenitic family.

High nickel, high molybdenum, with copper. Built for sulphuric acid service.

6% molybdenum super-austenitic with nitrogen. PREN above 42.

Nickel-iron-chromium with copper and niobium. Developed for sulphuric acid.

Roughly equal austenite and ferrite. Around twice the yield strength of 316L.

Martensitic PH grade. Machine soft, then age to tensile strengths above 1300 MPa.

Ferritic and martensitic chromium grades. Magnetic, nickel-free, hardenable.

Nickel-chromium-iron alloy. Resists oxidation and chloride SCC to high temperature.

Nickel-chromium-molybdenum-tungsten. Resists both oxidising and reducing media.

Commercially pure nickel, minimum 99% Ni. The caustic service standard.