Stainless Steel 202 vs Stainless Steel 304

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

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

Choose SS 202 for: lower cost than 304, because manganese and nitrogen replace part of the nickel, higher annealed yield strength than 304 (260 MPa minimum to ASTM A240) and takes a bright, even polish for decorative and appliance finishes. Its limits: lower corrosion resistance than 304 and 316 and not suitable for coastal, outdoor-marine, chloride or chemical-process service.

Choose SS 304 for: widest availability and shortest lead time of any stainless grade, excellent formability and weldability and good resistance to atmospheric and fresh-water corrosion. Its limits: pits in chloride environments, including coastal air and seawater and not suitable for sulphuric, hydrochloric or reducing acid service.

Both grades are austenitic, with about 17 to 19 percent chromium. The difference is what stands in for nickel. SS 304 carries 8.0 to 10.5 percent nickel and at most 2.0 percent manganese. SS 202 carries only 4.0 to 6.0 percent nickel and makes up the austenite with 7.5 to 10.0 percent manganese and up to 0.25 percent nitrogen, against 0.10 percent at most in 304.

That substitution is the whole story of the two grades. Nickel is the expensive element, so 202 costs less, and manganese plus nitrogen strengthen the steel, so annealed 202 is stronger. What manganese cannot do is match nickel's contribution to corrosion resistance and to forming.

On the typical pitting resistance figure used across this site, 304 sits at about 19 and 202 at about 17. The gap looks small on paper and is large in service. 202 is intended for dry and mildly humid indoor use. In coastal air, in water that carries chlorides, near cleaning chemicals and outdoors it is more likely to stain and pit than 304, which is itself only a general-purpose grade.

If the environment has chlorides, neither is the right answer and 316, duplex or a nickel alloy should be considered. The honest question is not which of the two is better but whether the part will ever be wet with anything other than clean water.

To ASTM A240 the minimum annealed yield strength is 260 MPa for 202 and 205 MPa for 304, with the same 515 MPa tensile minimum. That extra yield strength is real and is why 202 resists denting a little better in thin panels.

In forming, 304 is the easier grade. 202 work-hardens faster, so deep drawing, tight bends and spinning are more demanding, and it is a poorer choice for deep-drawn sinks and pans. Both weld well, but 202 should be welded with a procedure qualified for the 200 series rather than copied from 304.

On the relative index used on this site, where 304 is 1.0, 202 sits at about 0.75. That is an indication for specification triage, not a price, and actual prices are quoted per enquiry. A second difference matters to buyers: because 304 carries more nickel, its price follows the nickel market more closely, while 202 is less exposed to nickel swings.

A lower price is only a saving if the part lasts. A 202 part that corrodes in service costs more than a 304 part that does not, so judge the grade on the environment first and the price second.

Choose 202 for indoor, dry decorative and general fabrication: kitchenware, furniture, interior trim, appliance parts and similar work where appearance and price count and chlorides are absent. Choose 304 for food and dairy contact, outdoor and architectural use, anything washed with chemicals and anything that must last in a humid or coastal climate.

Whichever you choose, confirm the composition on the mill test certificate. Chemistry in the 200 series varies between mills more than in 304, and the certificate is the evidence of what you received.