This International Standard specifies the characteristics of extra-large-series, product-grade-C plain washers in the 100 HV hardness class, of nominal sizes (nominal thread diameters) ranging from 5 mm to 36 mm inclusive.
These washers are suitable for
— hexagon bolts and screws of product grade C in property classes up to and including 6.8, and
— hexagon nuts of product grade C in property classes up to and including 6 used in timber structures.
If dimensions other than those listed in this International Standard are required, they should be selected from those given in ISO 887.