Internal Hex, External Hex, Internal Torx, Hex, TX
AF, Torx, Imperial, SAE, Metric
7/8 ", 5.5 mm, 17 mm, 3/8 ", 11/16 "
1, 1-1/2, 3/4, 2-1/2, 3/8
12.5, 6.35, 9.53, 19.05, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide