The holding power of an ordinary wood screw is a significant improvement over a nail because of the additional surface area created by the threads wrapped around the shank. The right kind of screw in the right size hole will hold for many a year, perhaps indefinitely if the fastener isn’t subjected to much stress. If there is stress on the joint, however, the hard metal screw can – and usually will – wear away at the softer wood, eventually enlarging the hole and loosening the screw. The wearing action only gets worse as the hole enlarges, often to the point that the screw ultimately just falls out. The good news is that a loose screw isn’t hard to fix. In fact, there are several fixes, though some are better than others. Just Use a Bigger Screw
This fix takes the least work, and – as you might expect – gives the poorest results. In many situations you can’t use a thicker screw (a #10 instead of a #8, for instance); in others you can’t fit in a longer screw. In either case, the holding power of the new screw is compromised by the existing damage, so this solution is only recommended for temporary fixes.
