Internal Hex, External Hex, Internal Torx, TX, Hex
Metric, AF, Imperial, Torx, SAE
13/16 ", 5/16 ", 3/16 ", 15 mm, 5/8 "
1/4, 3/4, 2-1/2, 1/2, 3/8
19.05, 6.35, 25.4, 38.1, 9.53
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide