countersink

1 of 2

verb

coun·​ter·​sink ˈkau̇n-tər-ˌsiŋk 

countersunk ˈkau̇n-tər-ˌsəŋk  ; countersinking

transitive verb

1

: to make a countersink on (a hole)

2

: to set the head of (something, such as a screw) at or below the surface

countersink

2 of 2

noun

1

: a bit or drill for making a funnel-shaped enlargement at the outer end of a drilled hole

2

: the enlargement made by a countersink

Illustration of countersink

• countersink 1

Examples of countersink in a Sentence

Recent Examples on the Web

Verb

Drawer Construction Bore and countersink appropriate pilot holes in the drawer parts, and screw the drawer box together [15]. —Neal Barrett, Popular Mechanics, 5 June 2021

Use a combination drill bit/countersink to bore pilot holes in the shelf and top, then drive screws to fasten them in place [12/13]. —Neal Barrett, Popular Mechanics, 5 June 2021

With the drill press and a 5/32-inch-diameter bit, bore and countersink pilot holes in each block. —Neal Barrett, Popular Mechanics, 14 Nov. 2020

Attach legs: Hold each rear leg in place and countersink two evenly spaced holes through the seat slat and into the top of the leg. —Ted Kilcommons, Popular Mechanics, 18 July 2020

Lay out the holes first and drill and countersink them. —Popular Science, 9 Aug. 2020

Now, assemble per the photo and countersink the screws. 💡When decorating, avoid a high-gloss paint or finish, which is so slick the bags will slide off the board. —Popular Mechanics Editors, Popular Mechanics, 11 Apr. 2020

Noun

One of the key features to notice is how the movement bridge beveling varies in its proximity to the countersinks – everything from relatively distant, to just barely touching at their exact edges, to actually flowing across a countersink proper. —Jack Forster, Bloomberg.com, 20 Jan. 2021

This set of countersink drill bits includes five different sizes, as well as a rotating depth stop to prevent any accidental damage to your workplace. —Alex Rennie, Popular Mechanics, 2 Dec. 2022

One of the key features to notice is how the movement bridge beveling varies in its proximity to the countersinks – everything from relatively distant, to just barely touching at their exact edges, to actually flowing across a countersink proper. —Jack Forster, Bloomberg.com, 20 Jan. 2021

Other countersink sets have other types of quick-change drill and drive mechanisms. —Roy Berendsohn, Popular Mechanics, 4 Nov. 2021

Drill two evenly spaced holes through the joint with a 3⁄8-inch countersink bit, and fasten with 1-inch screws. —Ted Kilcommons, Popular Mechanics, 18 July 2020

If screw heads sit slightly above the surface, remove, countersink, and screw back in. —The Editors Of House Beautiful, House Beautiful, 11 Feb. 2015

Word History

First Known Use

Verb

1816, in the meaning defined at sense 1

Noun

1816, in the meaning defined at sense 1

Kids Definition

countersink

1 of 2 verb

coun·​ter·​sink ˈkau̇nt-ər-ˌsiŋk 

countersunk -ˌsəŋk  ; countersinking

1

: to make a countersink on (a hole)

2

: to set the head of (as a screw) at or below the surface

countersink

2 of 2 noun

1

: a bit or drill for making a countersink

2

: a funnel-shaped enlargement at the end of a drilled hole