NBN EN ISO 7090 : 2000

Characteristics of normal-series, product-grade-A plain washers chamfered at the outside diameter, in the 200 HV and 300 HV hardness classes and of nominal sizes (nominal thread diameter) ranging from 5 mm to 64 mm inclusive. 200 HV are suitable for: bolts and screws of grades A & B/property classes up to/incl 8.8; nuts of grades A & B/property classes up to/incl. 8; bolts, screws and nuts of stainless steel of similar chemical compositions; case hardened thread rolling screws. 300 HV are suitable for bolts and screws of product grades A & B/property classes up to/ incl. 10. Dimensions other than those in this standard should be selected from those given in ISO 887.