A Screw with The Countersunk Head

Screw heads are available in three main shapes, but the countersunk may be the commonest. The name "countersunk" explains the state which pull into a hole with sloping sides and describes the screw head fits into the surface of what you're fixing. This hole is built in wood used with a special countersink bit; many metal fittings like hinges come with their screw holes already countersunk.

The raised countersunk head is usually worked with exposed metal fittings; while the round head is applied for fixing metal fittings without a countersink to materials.