Make the hole in the piece into which the screw goes small enough for the thread of the screw to catch tight.

Then all the strength exerted in driving, goes toward drawing the pieces together, not in overcoming friction.

The hole must be deep enough, especially in hard wood and for brass screws, to prevent the possibility of twisting off and breaking the screw.

Soap is often useful as a lubricant to facilitate the driving of screws.

Where it is desirable that the heads do not show, a hole may first be bored with an auger-bit large enough to receive the head and deep enough to insert a plug of wood, which is cut out with a plug-cutter, Fig.