STAINLESS STEEL OVERVIEW: ALLOY CLASSIFICATIONS

200 Series Austenitic – Alloys: 201, 202, 203, 204 & 205

Chromium-nickel-manganese alloy with high strength in the annealed . Non-magnetic, not heat treatable and has excellent formability for several forming applications.

Typical use: washing machine tubs, structural applications.

300 Series Austenitic – Alloys: 301, 302, 303, 304, 305, 308, 309, 310, 314, 316, 317, 321, 330, 347, 384

Chromium-nickel alloy can develop high strength by cold working. Non-magnetic, not heat treatable and has good formability. Additions of molybdenum can increase the corrosion resistance.

Typical use: Food equipment, chemical equipment, architectural applications

400 Series Ferritic – Alloys: 405, 409, 429, 430, 434, 436, 442, 446

Straight chromium alloy, magnetic, but not heat treatable.

Typical use: Automotive trim, cooking utensils

400 Series Martensitic – Alloys: 403, 410, 414, 416, 420, 422, 431, 440

Straight chromium alloy, magnetic, but can be hardened by heat treatment.

Typical use: Fasteners, pump shafts, turbine blades

Precipitation Hardening – Alloys: 13-8, 15-5, 15-7, 17-4, 17-7

Chromium-nickel, martensitic or austenitic. Develop strength by precititation hardening reaction due to heat treatment.
Typical use: valves, gears, petro-chemical equipment

Duplex – Alloys: 329, 2205, 2304, 2507, 3RE60

Chromiun-nickel-molybdenum. More resistant to stress corrosion cracking than austenitic, yet tougher than fully ferritic alloys.

Typical use: pipelines, pressure shafting

For more data on stainless alloys, please see the SSINA handbook “Design Guideline for the Selection and Use of Stainless Steel”.