Internal Hex, Internal Torx, External Hex, Hex, TX
Metric, AF, Torx, Imperial, SAE
3/16 ", 7/32 ", 9/32 ", 5/16 ", 7/16 "
1/4, 3/8, 1/2, 3/4, 2-1/2
9.53, 38.1, 6.35, 25.4, 19.05
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Gun-metal, Phosphatized, Oxidised, Black Phosphate, Black Oxide