Definitions for "Counterbore"
A flat-bottomed cylindrical enlargement of the mouth of a hole, usually of slight depth, as for receiving a cylindrical screw head.
A kind of pin drill with the cutting edge or edges normal to the axis; -- used for enlarging a hole, or for forming a flat-bottomed recess at its mouth.
To form a counterbore in, by boring, turning, or drilling; to enlarge, as a hole, by means of a counterbore.
Keywords:  pilot, flutes, helical, rotary, barrel
A rotary, pilot guided, end cutting tool, having one or more cutting lips and usually having straight or helical flutes.
The recessed area in the discharge end of an injection barrel which acts as a pilot to assure the concentric fitting and seal surface of the end cap to the barrel.
Keywords:  tuning, chamber
The tuning chamber.