A2 (304 S15) This has good resistance to corrosion,except in severe industrial and Marine Condition. It is often used inside Marine vessels where it doesn't come into direct contact with seawater. Other applications: UPVC Cladding, Garden tools, Roofs, Outside fixings, Motor Cycles, Caravans, Lawn Mowers, Radio Control models, kitchens, bathroom's, etc.
A4 (316 S31) This has a greater corrosion resistance than A2 in certain environments, and is often used for Marine applications especially when coming into direct contact with saltwater. Ideal For deck fittings and on the hull.
CORROSION AND OXIDATION CHARACTERISTICS
416 S21 formerly EN 56AM More often referred to as stainless iron and not stainless steel. Owing to its low corrosion resistance is not recommended for atmospheric exposure unless it is able to be cleaned regularly. Has a good resistance to nitric acid attack but is inferior to austenitic stainless steels. Magnetic.
431 S29 formerly EN57 This specification has a greater corrosion resistance and tensile strength over 416 S21 and because of this, is widely used in the aircraft industry. It also has a good wear resistance surface due to the martensitic formation of the structure when it has been quenched cooled after heat treatment. This often lends itself to such applications as spindles, pivot pins and roller bearings, etc. Magnetic
430 S15 Fairly good resistance to outdoor corrosion if cleaned regular. Can also be used with some weak acids and foodstuffs; good oxidation resistance up to 800°C. It is quite often used in the food processing industry in sheet form and a limited range of fasteners can also be supplied. Magnetic.
304 S15 formerly EN 58E A2-18/8 Except in severe industrial and marine conditions this specification has resistance up to 850°C (particularly when stabilised with Titanium) and its ability to resist organic acids is satisfactory under certain conditions. It is not recommended for use with acids such as hydrochloric and chlorides and is non-magnetic except when heavily cold worked.. Although not hardenable by heat treatment, the cold working greatly strengthens the product.
