This International Standard specifies the characteristics of small-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 36 mm inclusive.
Washers of hardness class 200 HV are suitable for
— cheese head screws in property classes up to and including 8.8, or made of stainless steel;
— hexagon socket head cap screws in property classes up to and including 8.8, or made of stainless steel;
— hexalobular socket head cap screws in property classes up to and including 8.8, or made of stainless steel;
— case-hardened thread rolling screws with cheese heads. Washers of hardness class 300 HV are suitable for
— hexagon socket head cap screws in property classes up to and including 10.9;
— hexalobular socket head cap screws in property classes up to and including 10.9.
If dimensions other than those listed in this International Standard are required, they should be selected from these given in ISO 887.
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.