Woodhaven 8500 Mortise Bit,Whiteside" /> Carbide Tipped 1/2" Cutting Diameter 1/4" Cut Length, 2-1/4" overall length. 8500 is the most popular bit to use with our jigs. Get the 8505 (3/4" cut length) if your door frame has a 1/2" thick stop attached that the jig has to be mounted above. 5/8" Bearing, 1/4" shank.