All All Zinc Size 1" - 8 Size 7/8" - 9 Size 5/8" - 11 Size 1/8" - 7 Size 3/4" Size 1/2" - 13 Imperial (Inch) Metric (Millimeter) Coarse Thread [UNC] Fine Thread [UNF] Extra-Fine Thread [UNEF] UNS Steel Size 3/8" 0-80 2-56 4-40 6-32 8-32 10-24 10-32 12-24 1/4-28 1/4-32 5/16-18 5/16-24 5/16-32 3/8-16 3/8-24 3/8-32 7/16-14 7/16-20 1/2-13 1/2-20 1/2-28 9/16-12 9/16-18 5/8-11 5/8-18 3/4-10 3/4-16 7/8-9 7/8-14 1-8 1-14 1-1/8-7 1-1/4-7 1-1/4-12