The glue joint cut by this bit is strong and self-aligning. One setup produces both halves of the joint. Adjust the bit so the center of the profile aligns with the stock center. Cut one part face down, the mate face up. Bit works on stock center between 5/8" and 1" in thickness. Must be used in a table-mounted router. Since there is a no guide bearing, use the router-table fence to control the cut.