Slot nuts by Vöhrs

Standard Drop-In T-Nut 8020 T-Slot Hardware slot nuts Heat treated steel T-Slot Nuts with black oxide finish feature an imperfect thread in the base of the T-nut to eliminate any danger of screwing the clamping slot temple free play Tapped through, 38-16 pitch x 58 high x 916 slot depth $23

slot blood suckers FC06 T-slot nut manufactured from hardy carbon steel in a black oxide finish for added durability Available in a range of metric sizes