The diameter for rivets and black holes shall be taken as the nominal diameter of a rivet plus 1.5 mm for rivets of nominal diameter less than or equal to 25 mm and 2.0 mm for rivets of nominal diameter exceeding 25 mm unless specified otherwise. The holes for fitted and turned bolts shall be reamed or drilled large by a range of 0.2 to 8 mm depending upon the diameter of bolts.