Parallel keys high form, round-headed without bore DIN 6885A-A5 4x4x18

Stainless steel refers to alloyed or unalloyed steels that contain at least 10.5% chromium and less than 1.2% carbon. Colloquially, stainless steel is also referred to as stainless steel (NiRo), although not all stainless steel is the same as "stainless".

The term plain indicates a completely untreated, merely oiled, smooth surface for all DIN and ISO screws such as wood screws, hexagon head screws, threaded rods, nuts and many types of washers.

Grade 1.4571 is an austenitic stainless steel of the A5 type. It possesses the properties of the A4 type, but with increased temperature resistance. Furthermore, the A5 type is stabilised by the addition of titanium. This prevents intergranular corrosion. The material has good forgeability, excellent weldability and poor machinability. It does not exhibit brittle fracture behaviour and can therefore be used at low temperatures.