BS EN ISO 7093-1:2000

• 21.060.30 Washers, locking elements

This part of ISO 7093 specifies the characteristics of large-series, product-grade-A plain washers in the 200 HV and 300 HV hardness classes and of nominal sizes (nominal thread diameters) ranging from 3 mm to 36 mm inclusive.

Washers conforming to this part of ISO 7093 are intended for use in cases where soft material pieces are to be clamped or where there are large clearance holes in the workpiece. Nevertheless, in the latter case, the suitability of the washer thickness should be checked.

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.

If dimensions other than those listed in this part of ISO 7093 are required, they should be selected from those given in ISO 887.