Tri Groove Driver Sockets are made of Alloy Steel.. The TriGroove tamper resistant fastener drive style is also referred to as: Tri-Groove, T Groove, Trident Drive and Coned Trident Drive.. Security nuts are installed using a special Tri Groove socket, which grips the indentations along the outside of the fastener to turn the nut along a thread.. Tri Groove nuts can only be fastened with Tri Groove Driver sockets. Standard sockets fit 1/4" square drive. Fits tri-groove screw sizes 6 & 8.
