NBN EN ISO 7089 : 2000

Characteristics of normal-series, product-grade-A plain washers in the 200 HV and 300 HV hardness classes and of nominal sizes (nominal thread diameters) ranging from 1,6 mm to 64 mm inc. are defined. Washers of hardness class 200 HV are suitable for: hexagon bolts and screws of product grades A and B in property classes up to and including 8.8; hexagon nuts of product grades A and B in property classes up to and including 8; hexagon bolts, screws and nuts of stainless steel of similar chemical composition; case-hardened thread rolling screws, washers of hardness class 300 HV are suitable for hexagon bolts and screws of product grades A and B in property classes up to and including 10.9; hexagon nuts of product grades A and B in property classes up to and including 10.