Tri Groove security nuts feature a tapered diameter, making the nuts resistant to gripping devices. 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.
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.