CMT The beautifully crafted dovetail joint is a classic that appeals to both professionals and novices alike. Admired for its attractiveness in exposed joint projects, the dovetail is remarkable strong and functional. CMT Dovetail bits are designed to fit all popular jigs including Leigh, Keller, JoinTECH and Omnijig systems. Note: Pre-cut your dovetails with a straight bit to reduce bit breakage. Use a diameter slightly less than the small diameter at the neck of the dovetail bit. This will also improve chip removal and safety.