AISI 301
An austenitic stainless steel, which because of its ability to attain high strength and ductility through moderate of severe cold working, can be used for automobile trims, convey or belts, transportation cars such as railway coaches, metal fixtures for construction purposes, roof drainage products, storm doos frames and tableware.
AISI 304
It is the most widely used austenitic stainless steel. Popularly known as 18/8 stainless steel, it has excellent corrosion resistance and forming characteristics. Used in chemical, petrochemical and fertilizer industries, and as equipment in diary, food processing, pharmaceutical industries, in hospitals, households as kitchenware, cryogenic vessels and as heat exchangers in air conditioning refrigeration, for machinery in paper, pulp and textile beverage sectors.
An austenitic stainless steel similar to AISI 304 with less carbon(0.03% max). is used in place of AISI 304 for improved resistance to intergranular corrosion it is used for parts and structures which cannot be heat treated for stress relieving after welding.
AISI 309 / AISI 309S
These are austenitic stainless steels which are strong and tough. Because of their higher nickel and chromium content, there are used for applications requiring high scaling resistance and corrosion resistance. They find their use for air heaters, annealing boxes, bake oven equipment, boiler baffle plates, carburizing boxes, chemical processing equipment, dryers, exhaust manifolds, furnace parts, gar turbine parts, heat exchangers, jet engine parts, oil burner parts, oven equipment, petroleum refining equipment, etc.
AISI 310 / AISI 310S
These are austenitic types with higher chromium and nickel content than 309/309S. Because of their relatively high creep strength and mechanical properties at higher temperatures these steels find their applications for higher temperatures and severe service conditions. Used for air heaters, annealing boxes, ovens, carburizing boxes, fire box sheets, furnace linings, furnace stacks and dampers, gas turbine parts, head exchangers, kiln linings, nozzle diaphragm assemblies for turbo jet engines, oil burner parts paper mill equipment, oil refinery equipment, recuperators and so on.
AISI 316
An austenitic stainless steel with 2.0%  to 3% Mo. which improves corrosion resistance and imparts hot strength characteristics. Used for applications requiring resistance to pitting corrosion and in halogen atmospheres. Typical applications: architectural trims, marine exteriors, chemical processing equipment, food processing equipment, petroleum refining equipment, pharmaceutical equipment, photographic equipment, pulp and paper processing equipment, textile finishing equipment, etc.
An austenitic stainless steel. Modification of type AISI 316 (contains a maximum of 0.03% carbon) with reduced tendency towards carbide precipitation without addition of a stabilizing element. Recommended for parts which cannot be heat treated after welding.
AISI 317 / AISI 317L
There are austenitic stainless steels which are modifications of type AISI 316/ AISI 316L and offer increased chromium, nickel and molybdenum ranges for improved corrosion resistance. The steels were developed to resist attack of sulphurous acid compounds. They resist pitting in phosphoric and acetic acids. Applications include paper pulp handling equipment, process equipment for producing photographic chemicals, bleaching solutions and handling sulphurous, acetic, formic, citric and tartaric acids. They have the best corrosion resistance to body acids and blood and are recommended for surgical bone applications.
AISI 321
An austenitic stainless steel similar to AISI 304 but stabilized with titanium to avoid inter-granular corrosion. Type AISI 321 resists scaling and vibration fatigue. It is used for aircraft exhaust stacks and manifolds, pressure vessels, large mufflers for stationery diesel engines, carburetors, expansion bellows, stack liners, fire walls, etc.
AISI 347
An austenitic stainless steel similar to AISI 321 but stabilized by Columbium which does not appreciably reduce the overall corrosion resistance. Recommended in the range of 420 deg. - 900 deg. C for parts fabricated by welding and which cannot be subsequently annealed. Applications include airplane exhaust stacks, wleded tanks for chemicals, heat resistors, jet engine parts, expansion bellows, etc.
AISI 409
It is the lowest alloyed straight Chromium ferritic stainless steel. It replaces carbon steels and low alloy steels where some amount of heat or corrosion resistance and higher strength are required and where appearance is secondary. It is used for fins in heater tubes, transformer and capacitor cases, dry fertilizer spreaders, automotive exhaust systems including mufflers, resonators, silencers, pipes and emission control units, high pressure  agricultural spray tanks, culverts, shipping containers and farm equipments.
AISI 410 / 410S
AISI 410 is the most commonly used 12% Chromium martensitic stainless steel. Excellent combination of toughness and strength can be developed through proper heat treatment. This steel has better corrosion resistance in the hardened condition. It is a good choice when good formability and high strength are required and the end use demands resistance to mildly corrosive environment. It is used for furnace parts and burners operating below 650 deg. C micrometer parts, tray supports, caps and vaporizers in petroleum fractionating towers, lining for reaction chambers, coal screens, fishing tackle, keys, lamp brackets, rules and tapes, wall screens, steam turbine buckets, blades, bucket covers, pump parts, petrochemical equipment and press plates. Type AISI 410 S is a low carbon modification of AISI 410.
AISI 420
This steel contains min.0.15% C and 12% Cr. It can be thermally nardened to develop very high strength. Extremely useful for cutlery. Other applications include vegetable choppers, scissors, shears, tweezers, hand tools, dental and surgical instruments, etc.
AISI 430
AISI 430 with 19% Cr. is inferior to AISI 304 as regards deep draw ability. Though it does not have good corrosion resistance properties as the Cr-Ni steels, it is used under less severe corrosive atmospheres for chemical processing equipment, furnace parts, heat exchangers, oil burner parts, petroleum refining equipment, pyrometers, protection tubes, recuperators, rubber plant machinery, scientific apparatus, storage vessels, tubing, television cones, electrical appliances, solar water heaters, air conditioners, kitchenware, household appliances decorative trims, parts for washing machines etc.
AISI 434
A ferritic stainless steel similar to AISI 430 but containing about 1% Mo. It has better corrosion resistance than AISI 430. It is widely used for exterior automotive moulding and trims and applications where improved corrosion resistance to pitting attack from various de-icing chemicals is required.