External Hex, Internal Torx, Internal Hex, TX, Hex
Imperial, Metric, AF, Torx, SAE
7/16 ", 3/8 ", 5.5 mm, 5/16 ", 11/16 "
1/4, 1, 1-1/2, 2-1/2, 3/4
19.05, 38.1, 6.35, 25.4, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide