This standard specifies the characteristics of large-series, product-grade-A plain washers in the 200HV and 300HV hardness classes and of nominal sizes (large thread diameters) ranging from 3mm to 36mm inclusive.
Washers conforming to this standard 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 shall be checked.
Washers of hardness class 200HV are suitable for:
——Hexagon bolts and screws of product grades A and B in property classes up to and including 8.8;
——Hexagonal nuts of product grades A and B in property classes up to and including 8;
——Hexagon bolts, screws and nuts of stainless steel and similar chemical composition;
——Case-hardened thread rolling screws.
Washers of hardness class 300HV are suitable for:
——Hexagon bolts and screws of product grades A and B in property classes up to and including 10.9;
——Hexagonal nuts of product grades A and B in property classes up to and including 10;
If dimensions other than those listed in this standard are required, they should be selected from those given in GB/T 5286.
