This t-track and t-slot router bit cuts slots for bolts that have a 1-1/16" wide x 5/16" high heads with up to 3/8" shaft diameter - 1/4" shank. Create t slots for custom jigs and hold-downs or for picture frame keyhole hanging Premium C3 micro-grain tungsten carbide blades for a sharper & longer lasting edge For use on table mount and handheld router Silver induction brazing for maximum strength and durability, Weight: 0.06 Pounds, Manufacturer: Yonico