COUNTERBORE v. 3 definitions
To form a counterbore in, by boring, turning, or drilling; to enlarge, as a hole, by means of a counterbore.
PIN n.
r a hole, for enlarging the hole, or for sinking a recess for the head of a bolt, etc.; a counterbore. -- Pin grass. (Bot.) See Alfilaria. -- Pin hole, a small hole made by a pin; hence, any very small aperture or perforation. -- Pin lock, a lock having a cylindrical bolt; a lock in which pins, arranged by the key,…
PLUG n.
nder instead of a point, so as to follow and enlarge a hole previously made, or to form a counterbore around it. -- Plug rod (Steam Eng.) , a rod attached to the beam for working the valves, as in the Cornish engine. -- Plug valve (Mech.), a tapering valve, which turns in a case like the plug of a faucet.…