A screw that turns empty after or while tightening can really annoy you. Neither the screw is fixed nor can it be tightened. What you can do when a screw goes crazy, we describe here in detail.
A spinning screw can happen anywhere
Many do-it-yourselfers know the situation. A screw is screwed in and then turns through empty. Even if you now wanted to replace the screw with a larger screw, you would have to get the smaller, first screw out of the screw hole first. It is important to know what kind of screw it is:
- a self-tapping screw in a material such as wood
- a screw inserted in a dowel
- a metric or imperial screw in a mating thread
self-tapping screw turns through
tapered screws are equipped with a wider thread than, for example, metric metal screws, as they are screwed into a matching mating thread. The thread practically cuts the thread in the workpiece with such screws. Typical materials would be wood (wood screw) and sheet metal (sheet metal screw).
Materials such as wood are usually blind holes, so the screw can not be pushed out from the other side. But now it is crucial why the screw can not be unscrewed. If the screw head is broken with the slot, so the screwdriver turns empty, a simple trick helps.
Screw head is defective
Take a rubber as from a jar seal. Put the rubber on the screw and put the screwdriver on it. The rubber provides so much support that the screw can now simply be unscrewed.
Thread does not grip properly
For all other screws, where the thread no longer works properly because it is destroyed, you also need a small, pointed flat-head screwdriver. Slide the screwdriver under the head of the screw and press it upwards.
At the same time take the second screwdriver, put it on the screw head and turn on the screw. Turn slowly and with feeling. The screw will now slowly unscrew. Schraube Screw inserted in a dowel rotates
If a screw is turning in a dowel, you must check whether the screw in the dowel or the dowel rotates with the screw. If the screw in the dowel turns empty and you do not want to use a larger screw, you can also resort to a trick here, depending on the required load. K You can cut a toothpick or a match to anchor length and insert it into the dowel. Then the screw is screwed in again. Alternatively, you can also fill plaster in the dowel hole with dowel and screw in the screw to stop or as needed. Then wait until the plaster or repair mortar has set.
If the dowel is screwed through with the screw
If the dowel itself rotates, you can use a similar trick if you do not want to replace the dowel with a larger dowel. Insert the screw into the dowel as far as possible without screwing it in, and then wrap the dowel with wire. Fill the drill hole with repair mortar or plaster and push the dowel back in. Wait for the mass to harden. Now tighten the screw.
Metric screw turns counter thread
It gets a bit more complicated. You can try the trick again with the second screwdriver, which is guided under the screw head. Pry up gently as you slowly unscrew the screw. In many cases, unscrewing such screws succeeds. Then you have to check which thread is broken.
Unfortunately, this is usually the mating thread to the screw. There is no choice but to cut the thread or cut a larger thread if it is a blind hole. If a screw hole penetrates, you can tighten a screw on the other side with nuts (stop nut, lock nut, etc.).
Tighten the screw
For blind holes, and if the screw is not over-stressed in the particular application, you can also try to glue a new screw with extra-solid threadlock adhesive or liquid metal. But that can also mean that this screw can be removed very difficult later.