Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, AF, Metric, Torx, SAE
3/16 ", 5.5 mm, 8 mm, 36 mm, 1-1/2 "
1-1/2, 1/4, 1, 2-1/2, 1/2
38.1, 19.05, 25.4, 6.35, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Oxide, Black Phosphate