Stainless steel brings corrosion resistance and a premium look, but grades differ sharply in how they machine and how hard they get.
304 — the workhorse
Excellent corrosion resistance and formability, but work-hardens during cutting, which can be tricky. Use it for food equipment, enclosures, and decorative parts.
316 — the marine grade
Adds molybdenum for better resistance to chlorides and saltwater. Slightly harder to machine than 304. Choose it for marine, medical, and chemical-exposed parts.
17-4 PH — the strong, heat-treatable one
Precipitation-hardening stainless that reaches high strength after a heat treatment, yet machines in the soft condition. Ideal for shafts, valves, and structural parts needing both corrosion resistance and strength.
Machining notes
Stainless work-hardens—use sharp tools, positive rake, and avoid dwell that lets the tool rub. Rigid setups prevent chatter.
FAQ
Which stainless is strongest? 17-4 PH in H900 condition, by a wide margin.
Best for outdoor use? 316 near coastlines; 304 inland. More in the materials guide.