ISO 3318:1990

Assembly tools for screws and nuts — Double-headed open-ended wrenches, double-headed ring wrenches and combination wrenches — Maximum widths of heads

Specifies the maximum outside head dimensions for wrenches, listed in ISO 1703 under numbers 4 and 8 to 14, except for wrench No. 12. Tabulates widths across flats from 3,2 mm up to 60 mm together with the corresponding outside head dimensions. This third edition cancels and replaces the second edition (1982).