What is the appropriate drilling operation for cutting a recess for a socket head cap screw?

The appropriate drilling operation for cutting a recess for a socket head cap screw is counterboring. This operation creates a cylindrical hole that allows the head of the cap screw to sit below the surface of the material, providing a flush finish. Counterboring not only enlarges the opening at the top of the hole to accommodate the screw head but also ensures that the screw can be driven in without any protruding edges, which is particularly important in applications where a smooth surface is essential.

In contrast, countersinking refers to creating a conical recess for flat-headed screws, which is not suitable for socket head cap screws that require a cylindrical recess. Reaming is used to achieve tight tolerances and smooth finishes on existing holes but does not create a recess. Tapping is involved in creating internal threads within a hole but does not facilitate the recess necessary for cap screw heads. Therefore, counterboring is the most appropriate choice for this specific application.