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 3.6mm to 36mm inclusive.
Washers of hardness class 200HV 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 standard are required, they should be selected from those 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.
