SFS thread-forming screws A5 TDA-S-S16/A4-6,5X60-R5

The wrench sizes for hexagon bolts and nuts are specified in ISO 272: 1982-01. The nominal wrench size on the workpiece (e.g. bolt, nut) is the same as that on the tool. However, there is some play between the two to allow the tool to be fitted without difficulty. The relationship between the nominal diameter d of the thread and the wrench size s is standardised in EN ISO 4014 and EN ISO 4017 for hexagon bolts, and in EN ISO 4032 for hexagon nuts (dimensions in mm).

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".

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.