Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, AF, Torx, SAE, Metric
5.5 mm, 11/16 ", 13/16 ", 5/16 ", 3/16 "
1-1/2, 3/4, 1, 2-1/2, 3/8
38.1, 6.35, 19.05, 9.53, 25.4
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Phosphate, Black Oxide