Austenitic steels with designations 1.4301 and 1.4307 are the commonest stainless types and contain 18% chromium and 8% nickel. The difference between the two grades is that in 1.4301, the maximum allowed carbon content is higher than for 1.4307 which can mean that 1.4301 has marginally higher strength. In practice, the difference in carbon between 1.4301 and 1.4307 is often of little significance. However, if welding is to be performed, 1.4307 is the preferred choice since corrosion resistance in the vicinity of the weld could be impaired for 1.4301.
Flat formats of 1.4301/1.4307 are standardised in EN 10088-2. This standard covers hot-finished plate with thicknesses up to and including 75 mm.
Grades 1.4301 and 1.4307 show good resistance to corrosion in neutral water both indoors and outdoors. The steels also exhibit immunity from atmospheric corrosion. However, these stainless grades are less suitable if the environment is acidic or contains chlorides. In such instances, higher alloyed grades will be needed.
The formability, e.g. by bending or roll forming, of hot-finished plate in both 1.4301 and 1.4307 is very good, often equivalent to or even better than for hot-rolled plate in carbon steel. Both grades are also characterised by very good weldability and they seldom pose any problems in fabrication of welded structures. However, machining (milling, drilling) of plate in 1.4301/1.4307 can be troublesome but processing is facilitated by making use of tooling specifically designed for machining stainless steel.
The surface finish of 1.4301/1.4307 plate as stocked is 1D (annealed and with surface oxide removed by pickling).