t6slotEngineering Hardware Standards. Dimension Table for T-Slots, Bolts, and Nuts per. American National Standard T-Slots ANSIASME B5.1M-1985. 1. Width of tongue used with the T-SlotsGAP Engineering supplies T-Slot Aluminium Extruded Profiles and accessories to customers throughout Australia.. T-Slot Aluminium refers to a system of structural Aluminium profiles with