Internal Hex, Internal Torx, External Hex, Hex, TX
Imperial, Metric, Torx, AF, SAE
5.5 mm, 11 mm, 11/16 ", 3/16 ", 5/16 "
1/4, 3/4, 2-1/2, 1/2, 3/8
25.4, 38.1, 6.35, 12.5, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide