This standard gives the general dimensions and tolerances of black hexagon bolts,screws and nuts with ISO metric threads in diameters from 5 mm to 68 mm inclusive; basic dimensions for sizes greater than M68 are also included.
This standard specifies mechanical properties of black hexagon bolts,screws and nuts made of carbon steel and alloy steel when tested at an ambient temperature range of 10℃ to 35℃. Dimensional requirements are included for bolts,screws and nuts finished black all over and for those which have partially machined finishes.