Tired of countersinks that slip on the drill bit after one or two holes? After tightening the set screw half a dozen times, the drill bit is usually so scarred up that there is no hope of any further adjustment. Make it Snappy countersinks are designed so that the countersink locks onto the hex shank, and the drill bit slides through the center. A set screw allows adjustment of the drill bit for different screw lengths. Because the drill drives the hex shank of the countersink, instead of the drill bit itself, slippage is eliminated! The bit may be replaced with equal sized bits of any point design or length.