Fixture for grinding 60-degree counter center of extension drill

The utility model discloses a fixture for grinding a 60-degree counter center of an extension drill, and relates to a fixture for grinding the extension drill. The fixture aims at solving the problems that the machining accuracy is low and the quality of the subsequent finish machining is influenced due to low positioning accuracy when a chuck is directly used for clamping a drill to grind the 60-degree counter center currently. A Mohs No. 4 taper shank of a cutter rod is matched with a machine tool spindle taper hole; a circular table hole and an auxiliary hole are formed in the outer end face of a cylinder axially; the inner diameter of the auxiliary hole of the cutter rod is matched with the outer diameter of a straight shank of the drill; an inner hole of a clamping sleeve is matched with the straight shank of the drill; at least two open grooves are formed in a side wall of the clamping sleeve; one end of a clamping nut is provided with a drill through hole; an inner shoulder hole is formed in the other