Internal Hex, External Torx, External Hex, Hex, TX
Metric, Imperial, Torx, AF, SAE
8 mm, 9/16 ", 15/16 ", 5/16 ", 3/16 "
1, 1-1/2, 2-1/2, 3/8, 3/4
19.05, 38.1, 9.53, 6.35, 12.5
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide