Fully threaded T-slot bolts allow the stud to pass all the way through the nut to contact the bottom of the T-slot and provide more holding power than partially threaded nuts.

Partially threaded T-slot nuts prevent the stud from passing through to the back of the nut, which ensures that the stud doesn't contact the base of the T-slot.

Quarter-turn T-slot nuts insert from the end or top of the T-slot, which allows additional T-slot fasteners to be installed between two existing fasteners. Sometimes called rhombus T-slot nuts, they have a lower maximum load capacity than other T-slot nuts.