Abstract: A finishing tool rides upward and downward on the surface of a tap. A spring urges the finishing tool toward an outer end of the tap. The finishing tool is guided along a helical flute on the surface of the tap. Cutting edges on the finishing tool are ground to deburr the perimeter of a hole being tapped either during entry of the tap into the hole or during withdrawal. When the cutting edges provide deburring during withdrawal, the helix angle of the helical flute must be less than a critical helix angle to avoid jamming. When the cutting edges provide deburring during entry of the tap, the critical helix-angle limitation is eliminated.

Abstract: A finishing tool rides upward and downward on the surface of a tap. A spring urges the finishing tool toward an outer end of the tap. The finishing tool is guided along a helical flute on the surface of the tap. Cutting edges on the finishing tool are ground to deburr the perimeter of a hole being tapped either during entry of the tap into the hole or during withdrawal. When the cutting edges provide deburring during withdrawal, the helix angle of the helical flute must be less than a critical helix angle to avoid jamming. When the cutting edges provide deburring during entry of the tap, the critical helix-angle limitation is eliminated.

Abstract: A hole-finishing hole finishing tool includes a pilot cone within which a quarter round section is free to be displaced in an axial direction. The quarter round section is resiliently biased away from a workpiece. When the tip of the pilot cone is inserted into a hole in a workpiece and force is applied, the quarter round section having a cutting element at its tip is displaced forward into contact with the perimeter of the hole, whereby chamfering is performed. The use of a single lip quarter-round cutting edge permits the tool to be used on small holes.

Abstract: A hole-finishing hole finishing tool includes a pilot cone within which a quarter round section is free to be displaced in an axial direction. The quarter round section is resiliently biased away from a workpiece. When the tip of the pilot cone is inserted into a hole in a workpiece and force is applied, the quarter round section having a cutting element at its tip is displaced forward into contact with the perimeter of the hole, whereby chamfering is performed. The use of a single lip quarter-round cutting edge permits the tool to be used on small holes.