These T-slot cutters are a type of non-indexable milling cutter that cuts perpendicular-walled slots and channels in metal. Dimensions of T-slots and T-slot bolts are standardized for specific bolt diameters. Cutting head diameters represent slot width. A T-slot nut is often used with a threaded clamp in a slot (track) that has been cut by a T-slot cutter. The job of the T-slot nut is to position and secure metal workpieces. The T-slot nut slides along the T-slot track. For alternative types of slot cutters, see our keyseat cutters and dovetail cutters.