Definition of countersink in English:


Line breaks: coun¦ter|sink
Pronunciation: /ˈkaʊntəsɪŋk

verb (past and past participle countersunk)

[with object]
  • 1Enlarge and bevel the rim of (a drilled hole) so that a screw, nail, or bolt can be inserted flush with the surface: drill and countersink the hole for mounting the ladder to the wall
    More example sentences
    • Drill and countersink screw holes for mounting screws.
    • Drill four 3/16-inch clearance holes in each rib before countersinking the top surface to bring the screw head flush.
    • I've also countersunk the holes so no screwheads stick up later on.
  • 1.1Drive (a screw, nail, or bolt) into a countersunk hole: (as adjective countersunk) countersunk screw heads
    More example sentences
    • It's helpful to first pre-drill a small hole in the wood where you want to countersink the brass screws.
    • Flat heads are always countersunk or rest flush with the surface.
    • A thin layer of thinset adhesive is applied to the top of the plywood using a notched trowel, then the cement board is put in place and secured with flathead screws that are countersunk into the surface.

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