Defines 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 1,6 mm to 64 mm inclusive. Washers conforming to this part of ISO 7093 are intended for use where soft material pieces are to be clamped, or where there are large clearance holes in the workpiece. In the latter case, the suitability of the washer thickness should be checked.