Internal Hex, External Hex, Internal Torx, TX, Hex
Imperial, AF, Metric, Torx, SAE
5.5 mm, 8 mm, 26 mm, 30 mm, 1-1/2 "
1-1/2, 1, 2-1/2, 3/8, 3/4
38.1, 9.53, 25.4, 19.05, 6.35
Special Steel, Molybdenum Steel, Alloy Steel, Steel, Chrome Molybdenum Alloy Steel
Phosphatized, Gun-metal, Oxidised, Black Phosphate, Black Oxide