BS 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.

This International Standard specifies the 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 1,6mm to 64mm inclusive.

Washers of hardness class 200 HV are suitable for

• hexagon bolts and screws of product grades A and В in property classes up to and including 8.8;

• hexagon nuts of product grades A and В 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 В in property classes up to and including 10.9;

• hexagon nuts of product grades A and В in property classes up to and including 10.

If dimensions other than those listed in this International Standard are required, they should be selected from those given in ISO887.

When soft material pieces are clamped, or large clearance holes in the workpiece are used, the user should check the technical suitability of this type of washer.