For coolant-inducing air-feed drills, we offer these special shanks, collars, and reducers with internal coolant passages. The coolant-type 21000-series bushings shown here (numbered as 11000 series for coolant type) have 3/4-16 mounting threads. This series is available in three OD sizes to fit drill diameters from .0938" to .3750". Preferred sizes can be mounted by any method, including the use of Lock Liners, while other sizes have limited mounting options.