What shape is typically used to create a countersink?

The correct shape for creating a countersink is conical. A countersink is a conical hole that allows the head of a screw, bolt, or other fastener to sit flush with or below the surface of the material in which it is embedded. The conical shape directs the force of fastening in a way that provides a secure fit, reducing potential wear and ensuring that the fastener can be properly seated. This design also allows for a smooth surface finish, improving the aesthetic and functional aspects of the assembly.

In contrast to other shapes, a conical countersink effectively accommodates the angle of a fastener's head, which is typically flat or has a slight dome, allowing for better stability and alignment during the fastening process.