A counterbore hole is usually used when the head of a fastener, such as a hex head or socket head capscrew, is required to be flush with or below the level of a workpiece's surface.

Dec 30, 2024 · A counterbore creates a flat-bottomed, enlarged opening so that the head of a screw or bolt can sit flush with or below the surface, while a countersink creates a conical recess for the screw …

Aug 9, 2022 · A counterbore is a flat-bottomed cylindrical hole that is larger than and coaxial to another cylindrical hole. It is used to provide a flat and recessed mounting surface for mating parts.

What Is a Counterbore? A counterbore is a hole-making tool that enlarges a portion of an existing hole to create a flat-bottomed recess for a screw, bolt, or nut head.

Counterbore holes are flat-bottomed, cylindrical recesses in a part that allow the fastener heads to sit flush with the surface of the part.

The counterbore enlarges an existing hole and has a flat bottom, ensuring that the head of the fastener sits evenly and securely while maintaining a common centerline with the initial hole.

Counterboring is the secondary machining process of creating a cylindrical shape at the top of a hole using a counterbore. Counterbored holes are often used to recess socket head cap screws below the …

Jan 26, 2026 · At first glance, counterbore and countersink holes look similar—but they serve distinct purposes in both mechanical and electronic applications. This article explains what a counterbore is, …

A counterbore is a cylindrical, flat-bottomed recess machined into a hole to allow the head of a screw, bolt, or socket-head cap screw to sit flush or below the surface of a material.

Dec 16, 2022 · A counterbore involves adding a stepped hole, that recesses the head of the fastener (and washers where fitted). This cavity is cylindrical and generally flat/perpendicular at its lower face, …