Flat discs with chamfer, normal row ISO 7090-stainless A5 200 HV 13

Grade 1.4571 is an austenitic stainless steel of the A5 type. It has the properties of the A4 type, but with improved temperature resistance. The A5 grade 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.

The combination of strength classes for flat washers with those for bolts and nuts is governed by ISO 898-3:2018, Table 1. Washers with a hardness of 200 HV are suitable for applications with heat-treated bolts up to strength class 8.8 and nuts up to class 8. Applications involving bolts of strength classes 9.8 and 10.9 and nuts of class 10 must be checked during installation. Combinations with higher strength classes must not be used.

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.