When connecting wooden parts with wood screws with a countersunk head, we must make a recess to hide the head. This can be done with a larger diameter drill, but it is easy to drive too deep into the wood. It is enough to drill such a recess with the head of a steel lenticular screw. You only need to make a second on his forehead, additional incision, and deepen the existing incision. The countersink made in this way is very easy to drill in softwood, harder in hard and very hard.