Screws often come loose, whether it’s on a door hinge or it’s the fastener holding the armrest onto your rocking chair. The reason screws loosen is because the wood surrounding the threads has worn away, usually due to the wear and tear of movement over time. To tighten a screw, the hole needs more material for the threads to bite. This can be accomplished by simply adding wood to the screw hole.
Depending on the size of the hole, you can use a wooden golf tee, long wooden barbecue skewers or even toothpicks. In a pinch you can even whittle some scrap wood slivers with your pocket knife. Insert the wood pick into the hole as deep as it will go, then cut it flush with the mouth of the hole. Repeat this step until the hole is packed with wood. Then, reinsert the screw and tighten with a screwdriver. The threads of the screw should crush against the new wood fibers with outward pressure to mount securely inside the hole.