Internal Hex, External Hex, Internal Torx, TX, Hex
Imperial, AF, Metric, Torx, SAE
3/16 ", 7 mm, 5/16 ", 9/16 ", 11/16 "
1/4, 3/4, 2-1/2, 1-1/2, 3/8
6.35, 25.4, 19.05, 38.1, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide