This part of ISO 7093 specifies the characteristics of large-series, product-grade-C plain washers in the 100 HV hardness class, 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 100 HV are suitable for: hexagon bolts and screws of product grade C in property classes up to and including 6.8; hexagon nuts of product grade C in property classes up to and including 6; case-hardened thread rolling screws. If dimensions other than those listed in this part of ISO 7093 are required, they should be selected from those given in ISO 887