counterbore
verbEtymology From counter- (“against”) + bore (“hole”).
1
To create such a cylindrical recess.
- Derived terms
- back-counterbore
counterbore
nounEtymology From counter- (“against”) + bore (“hole”).
1
A cylindrical recess, typically machined at the mouth of a hole to admit a screw (such as a cap screw) so that the screw sits flush with a surface.
2
The cutter used to cut such a recess. (Also used, at less depth, for spotfacing.)
- Meronyms: flute, pilot (the land at the tip, which rides the hole as a guide), shank
- Related terms
- spotface