Internal Hex, Internal Torx, External Hex, TX, Hex
Imperial, Torx, AF, SAE, Metric
3/16 ", 4.5 mm, 9/32 ", 5/16 ", 5/8 "
25.4, 6.35, 12.5, 19.05, 38.1
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphated, Gun-metal, Oxidised, Black Oxide, Black Phosphate