| Type | Cr | Ni | Cmax | Other Elements | Family | Major Properties | Application |
| 303 | 17.00-19.00 | 8.00-10.00 | 0.15 | S 0.15 min | Austenitic. Non-Hardenable by heat treatment | Easily machinable.
Free-machining modification of Type 302 | Applications that require extensive machining operations. |
| 303 Se | 17.00-19.00 | 8.00-10.00 | 0.15 | Se 0.15 min | Austenitic. Non-Hardenable by heat treatment | Free-machining version of Type 302.
Produces better surface finish than Type 303. | Aerospace components
Pump and valve
Threaded machine products. |
| 304 | 18.00-20.00 | 8.00-10.00 | 0.08 | – | Austenitic. Non-Hardenable by heat treatment | Low carbon variation of Type 302. Minimizes carbide precipitation during welding | Food processing equipment and utensils
Kitchen appliances
Chemical containers and equipment |
| 304L | 18.00-20.00 | 8.00-10.00 | 0.03 | – | Austenitic. Non-Hardenable by heat treatment | Extra-low carbon content eliminates harmful carbide precipitation due to welding | Food processing equipment and utensils
Kitchen appliances
Chemical containers and equipment |
| 309 | 22.00-24.00 | 12.00-15.00 | 0.2 | – | Austenitic. Non-Hardenable by heat treatment | High strength and resistance to scaling at high temperatures | Heating elements
Aircraft and jet engine parts
Heat exchangers |
| 310 | 24.00-26.00 | 19.00-22.00 | 0.2 | – | Austenitic. Non-Hardenable by heat treatment | Higher alloy content improves basic characteristics of Type 309 | Industrial furnaces
Steam boilers
Thermocouple protection tubes |
| 316 | 16.00-18.00 | 10.00-14.00 | 0.08 | Mo 2.00-3.00 | Austenitic. Non-Hardenable by heat treatment | Mo improves general corrosion and pitting resistance and high temperature strength over that of Type 302 | Marine environments
Chemical processing
Medical implants |
| 316L | 16.00-18.00 | 10.00-14.00 | 0.2 | Mo 2.00-3.00 | Austenitic. Non-Hardenable by heat treatment | Extra-low carbon version of Type 316. Eliminates harmful carbide precipitation due to welding | Chemical and petrochemical industry
Medical equipment
Food and beverage industry |
| 317 | 18.00-20.00 | 11.00-15.00 | 0.08 | Mo 3.00-4.00 | Austenitic. Non-Hardenable by heat treatment | Higher alloy content improves basic advantages of Type 316 | Offshore oil rigs
Chemical storage tanks
Food processing plants |
| 321 | 17.00-19.00 | 9.00-12.00 | 0.08 | Ti 5 x C. min | Austenitic. Non-Hardenable by heat treatment | Stabilized to permit use in 800-1500°F temperature range without harmful carbide precipitation | Heat Exchangers
Aircraft Components
Kiln Linings |
| 347 | 17.00-19.00 | 9.00-13.00 | 0.008 | Cb + Ta 10 x C. min | Austenitic. Non-Hardenable by heat treatment | Characteristics similar to Type 321. Stabilized by Cb and Ta. | Collector Rings
Annealing Box Covers
Aircraft Exhaust Stacks |
| 348 | 17.00-19.00 | 9.00-13.00 | 0.08 | Ta 0.10 max Cb 0.20 max
Cb + Ta 10 x C min | Austenitic. Non-Hardenable by heat treatment | † Similar to Type 347 but Ta reduced for atomic energy applications | Heat Exchangers
Jet Engine Parts
Chemical Processing Equipment |
| 410 | 11.50-13.50 | – | 0.15 | – | Martensitic. Hardenable | Lowest cost general purpose stainless steel. Wide use where corrosion is not severe. | Cutlery and Kitchenware
Surgical and Dental Instruments
Firearms Components |
| 416 | 12.00-14.00 | – | 0.15 | S 0.15 min | Martensitic. Hardenable | Free-machining version of Type 410. | Automotive and Aerospace
Tooling and Equipment
Pump and Valve Components |
| 420 | 12.00-14.00 | – | 0.15 min | – | Martensitic. Hardenable | Similar variation of Type 410 but higher carbon produces higher strength and hardness. | Cutlery
Surgical Instruments
Needle Valves |
| 430 | 14.00-18.00 | – | 0.12 | – | Feretic. Non-Hardenable | Most popular of the chromium types. Combines good corrosion and heat resistance and mechanical properties. | Architectural Applications
Industrial Equipment
Cutlery and Kitchenware |
| 430 F | 14.00-18.00 | – | 0.12 | S 0.15 min | Feretic. Non-Hardenable | Free-machining version of Type 430. | Machined Components
Fasteners and Bolts
Pump Shafts |
| 440A | 16.00-18.00 | – | 0.60-0.75 | – | Martensitic. Hardenable | Series of high carbon types. Some basic composition with varying carbon content. Higher carbon produces higher strength and hardness but lower toughness. All Type 440 versions are corrosion resistant only in the hardened condition. | Valve Components
Ball Bearings
Surgical Instruments
Chisels
High-Quality Knife Blades |
| 440B | 16.00-18.00 | 0.75-0.95 |
| 440C | 16.00-18.00 | 0.95-1.20 |
| 446 | 23.00-27.00 | – | 0.2 | – | Feretic. Non-Hardenable | Similar to Type 442 but Cr increased to provide maximum resistance to scaling. | Heat Exchangers
Combustion Chambers
Gas Burner Components |
| 15-5 PH | 14.00-15.50 | 3.50-5.50 | 0.07 | Cu 2.50-4.50 | Martensitic. Precipitation hardened | Similar in properties and characteristics to 17-4 PH but has superior transverse ductility and toughness. | Aerospace Components
Nuclear Applications
Oil and Gas Industry |
| PH 15-7 Mo | 14.00-16.00 | 6.50-7.75 | 0.09 | Mo 2.00-3.00
Al 0.75-1.50 | Semi-Austenitic. Precipitation hardened | Special type similar to 17-7 PH but with higher strength. | Aerospace Components
Springs and Fasteners
Marine Applications |
| 17-4 PH | 15.50-17.50 | 3.00-5.00 | 0.07 | Cu 3.00-5.00 | Martensitic. Precipitation hardened | Special type that combines excellent corrosion resistance…high strength and hardness… low temperature hardening and good fabrication characteristics. | Aerospace Components
Medical and Dental Instruments
Oil and Gas Industry |
| 17-7 PH | 16.00-18.00 | 6.50-7.75 | 0.09 | AL 0.75-1.25 | Semi-Austenitic. Precipitation hardened | Special ultra-high strength type with good formability and excellent fabricating characteristics. | Aerospace Components
Springs and Fasteners
Automotive Industry |
