A counterbore hole is typically used when a fastener, such as a socket head cap screw or fillister head screw, is required to sit flush with or below the level of a workpiece’s surface.

What is a counterbore depth?

A counterbore hole is typically used when a fastener, such as a socket head cap screw or fillister head screw, is required to sit flush with or below the level of a workpiece’s surface.

What is meant by counterbore?

verb (used with object), coun·ter·bored, coun·ter·bor·ing. to enlarge (a drilled hole) along part of the length of the hole by drilling with a bit having a greater diameter.