A counter-sink is a type of hole that is drilled so that a screw can sit flush with the surface it is being used on. However, there are a number of synonyms for counter-sink that people might use, depending on what they are working on and the terminology they prefer. Some of the most common synonyms for counter-sink include chamfer, bevel, countersink hole, and conical bore. These terms all describe the same basic concept of creating a hole or indentation in a surface in order to allow a screw or fastener to be seated flush. Whether you call it a counter-sink or a chamfer, this technique can be a useful way to make your fasteners more secure and less visible.