[verb, noun koun-ter-singk; verb koun-ter-singk]
- to enlarge the upper part of (a cavity), especially by chamfering, to receive the cone-shaped head of a screw, bolt, etc.
- to cause (the head of a screw, bolt, etc.) to sink into a prepared depression so as to be flush with or below the surface.
- a tool for countersinking a hole.
- a countersunk hole.
Origin of countersink
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for countersink
Countersink this hole enough to allow the head to sink flush with the surface.Handwork in Wood
Bore all holes, where shown in the drawing, and countersink them.
Countersink the holes on the side from which the screws enter.
Countersink all holes, except the four holes which hold the supports for the cart handle.
Countersink the hole in the base on the under side with a 1/2-in.The Boy Mechanic, Book 2
- to enlarge the upper part of (a hole) in timber, metal, etc, so that the head of a bolt or screw can be sunk below the surface
- to drive (a screw) or sink (a bolt) into such an enlarged hole
- Also called: countersink bit a tool for countersinking
- a countersunk depression or hole
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012