One of the most common is British bolt, American bolts
Specification of British bolts: Common specifications are 2 #; 4 #; 6 #; 8 #; 10 #; 12 #; 1 / 4; 7 / 32; 5 / 16; 3 / 8; 1 / 2; 9 / 16; 3 / 4.Unit in (in.).
British nominal length specifications: common values are 1 / 4,5 / 16,3 / 8,7 / 16,1 / 2 5 / 8,3 / 4,1,23.Unit: in (in.).
