Internal Hex, External Hex, Internal Torx, TX, Hex
Metric, AF, Imperial, Torx, SAE
5/16 ", 7/8 ", 11/16 ", 23 mm, 1-1/2 "
1/2, 1, 1-1/2, 3/4, 2-1/2
38.1, 25.4, 9.53, 6.35, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphated, Oxidised, Black Phosphate, Black Oxide