What type of drill bit enlarges just the surface of a hole for screw accommodation?

The type of drill bit that enlarges just the surface of a hole for screw accommodation is the countersink. This tool is specifically designed to create a conical shape at the top of a pre-drilled hole. This allows a screw to sit flush with or below the surface of the material being drilled, providing a cleaner finish and preventing the screw from protruding.

Countersinks are often used when working with wood, plastic, or metal, ensuring that the head of the screw can be driven into the surface, which is particularly important in applications where a smooth surface is desired or where aesthetics are a consideration.

Other types of bits perform different functions. For example, an auger bit is mainly used to bore large holes in wood and is not designed to create a conical indentation. A spade bit is used for drilling larger holes in wood quickly but does not provide the specific countersinking feature. A masonry bit, on the other hand, is intended for drilling into hard materials like brick or concrete and does not accommodate screws in the same way.