309 stainless steel is an austenitic stainless steel that machines comparably to 304. However, 309 has superior corrosion resistance and strength. Cold working 309 will increase both strength and hardness and this stainless steel does not respond to heat treating.

309 is a highly alloyed stainless steel used for its excellent oxidation resistance, high temperature strength and creep resistance. The lower nickel content of 309 improves resistance to sulfur attack at high temperatures. It is tough and ductile, and can be readily fabricated and machined. 309S is the low-carbon version of 309, and is recommended for applications where sensitization, and subsequent corrosion by high temperature gases or condensates during shutdown may pose a problem. 309 is manufactured to ASTM A167 and 309S to ASTM A240 specifications.

309/309S is used exclusively for its high temperature oxidation resistance. It is common for 309, 310 and 321 to be used in the same piece of equipment in the various temperature regions.

If you are interested in other Stainless Steel Strips, please click 302, 303, 304, 304L, 304H, 309, 309S, 310, 310S, 310H, 316, 316L, 317/317L, 317LMN, 321, 321H, 330, 347, 347H, 904L, 403, 405, 409, 410, 410S, 410/HT, 416, 416HT, 420, 422, 430, 440C, Duplex 2205, Duplex 2304, Duplex 2507.