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Glite Dictionary
🛠️ A drill bit 🛠️ To enlarge opening 🕳️ A recessed hole
counterbore

counterbore

9.5
A drill bit that widens the top of a hole so a screw head sits below the surface
  • noun
  • /ˈkaʊntərˌbɔr/
  • Specialized
translation icon : contraboceto
  • Before inserting the screw, make a counterbore so the head will sit flush with the surface.

Examples

  • The carpenter chose a counterbore to make space for the screw heads so that they did not stick out.

  • To ensure the screws are flush with the surface, I used a counterbore to enlarge the top of the holes.

  • A special counterbore is required for hardware that needs to be recessed.

  • The mechanic used a counterbore to prepare the hole for the bolt head.

  • The counterbore is essential for installing flush screws.

  • Using a counterbore saves time during assembly.

  • When installing the shelf, make sure to drill counterbores for the screws to create a smooth finish.

Synonyms

countersink bit
vscounterbore
  • Specialized
8.6

A drill bit that makes the top of a hole wider so a screw head sits flat with the surface

is identical in meaning but also applies to other tools not only bits
countersink
vscounterbore
  • Specialized
8.4

A drill bit with a cone tip that makes the top of a hole bigger for a screw head

focuses on the drill-bit form rather than the broader tool term

Surface Forms

counterbore singular
counterbores plural

Morphology

counterbore = bore (semi-transparent) = counter + bore

The prefix 'counter-' suggests opposition or complement, but the specific meaning of enlarging a hole is specialized.

Etymology

Counterbore comes from two simple parts: counter meaning 'against' or 'on top of' and bore meaning 'to make a hole'. A counterbore is a special tool that makes a wider, flat-topped hole so a screw or bolt head can sit below or level with the surface.