How to unscrew a bolt or nut with torn edges, a licked self-tapping screw

Sooner or later, any owner is faced with a situation where a nut, bolt or self-tapping screw does not want to twist. There are several reasons for this: low quality metal, violation of technology (overheated self-tapping screws), rust, time, too much effort applied when tightening the connection. Nevertheless, it is possible to unscrew the bolt with the torn off edges, the lapped nut, the rusted joint. In this article, we’ll talk about how to do this. 

Unscrew the torn off bolts and nuts

Slicked edges on bolt heads or nuts are not uncommon. Excessive forces applied when tightening, and then when loosening, often lead to the fact that the border between the bolt faces is erased. If the bolt is not unscrewed, ordinary keys are powerless in this case – they simply scroll, and the fasteners remain in place.

There are several ways to unscrew shear bolts and nuts:

• With a gas wrench. With ribbed jaws, adjustable “tightening” and a fairly large leverage, an adjustable wrench helps in most cases. This tool is not uncommon, so the first thing to do if you need to unscrew fasteners with stripped threads is to try this method.
  

• Make new faces. Smaller, but sharper. This will allow you to better grip the nut with the same adjustable gas wrench. Facets do:
  • Grinder. Work carefully so as not to damage the surface under the nut / bolt head. This is a risky endeavor and should be taken as a last resort.
  • With a file. This method is more time consuming but safer. If there is no urgency, it is better to fine-tune the edges with a file.
• A pin can be welded onto the nut. With your hands or using a lever, you can unscrew the bolt with the torn off edges. The same method helps if the thread is “stuck”. During welding, the metal heats up, the rust is overheated, the dirt burns, after which the bolt or nut is unscrewed much easier.
• Weld a nut onto the licked head of the bolt. Then unscrew everything together with an ordinary key. But this method works if the caps are flat. If they are rounded, you can try to cut / grind off the top, then weld on the nut and try to unscrew it.
  

• Extractor can be used with large diameter bolts. Cut off the cap or nut, drill a hole in the size “for the existing extractor”. Insert the extractor pin and with a key, turn out the entire structure for the thick part, release the extractor.

If there is a plastic or rubber gasket under the bolt, remove it and try one of the suggested methods again. If you cannot unscrew the bolt with the torn off edges in all these ways, one thing remains: cut / saw off the cap and drill out the pin.

Rusty nut

Another problem that is familiar to motorists (and not only) is a rusty nut and / or thread. In this case, you should not make a heroic effort to unscrew the fasteners. Your edges will simply “merge” and one more problem will be added to the boiling thread. If, after a couple of attempts, it is not possible to unscrew, try the following methods one by one:

• Use a wrench to tap the bolt. There is a chance that the rust will crack and the nut can be unscrewed.
• Fill the connection with kerosene and wait. It will corrode the rust, after which it will be easier to unscrew the rusted nut. But during this operation, you can not smoke, turn on welding, be near an open flame.
  

• Warm up the nut. The metal will expand, making it possible to unscrew it. The trick is to keep the nut warm and keep the bolt shank cold, so it warms up quickly. To do this, use a construction hair dryer or open fire (be careful with this). If the screw is small, you can take a powerful soldering iron, heat it up to the maximum temperature, then quickly warm up the junction.
• This method will (almost) destroy the nut, so it should only be used in hopeless situations. Grooves are made on the edges (using a saw for metal, a grinder, a file). They rest against this groove with a flat screwdriver, giving it a direction in the direction of unscrewing. The handle is tapped with a hammer. If there is at least a couple of shifts, it may turn out to be unscrewed.
  

• Use a special puller (pictured above). With the help of a bolt, the pin rests against one of the faces, after which you can try to move it from its place. Due to the fact that a lever can be put on, it can work even in very difficult situations.

You can also fight rust with a lubricant. Try filling the joint with a flowing multi-purpose grease (available in cans of WD40). After waiting a couple of hours, we try to work with a key. It didn’t work – we try other methods one by one.

Self-tapping screws with torn off splines (asterisk)

If the overheated self-tapping screws are twisted / twisted a couple of times, their edges lose their sharpness, the screwdriver scrolls, and the screw itself remains in place. If it “sits” in wood, plaster, chipboard or other similar, not too hard materials, you can put a thin elastic band under the screwdriver (for example, for hair). Due to the elastic force, they achieve a tighter fit to the remaining edges, which helps to move the self-tapping screw out of place. The rest of the methods are more “traumatic”:

• Cut grooves inside the “licked” funnel, using a flat screwdriver, unscrew. This method is quite dangerous: if the walls of the “funnel” are too thin, there is a possibility that the screw head will simply crumble from effort. There will be only a screw that cannot be unscrewed in any way.
  

• Drill out and unscrew with a small diameter extractor.
• Take a chisel, grind it to the size of the cap. Put it on the hat, hitting it well with a hammer a couple of times. A new cap is formed and, at the same time, existing rust may crumble (if the self-tapping screw is stuck in the iron). Using the same chisel, try to move the stubborn screw from its place. To facilitate the process, you can drop oil on wood or WD40 grease on metal.
• Drill material around the cap, take a tube with an inner diameter slightly larger than the diameter of the cap, put it on the cap. Pour glue inside. When the glue hardens, unscrew the tube.
  

The remnants of a bolt or a stud without a head can be unscrewed as follows: cut a left thread in the remaining body, drip a moment with glue, screw in a left tap, leave for an hour. Drop oil on the main thread and also leave for an hour. Unscrew when the glue has set. If the remnants of a self-tapping screw are stuck in the wood, it is easier to seal up this hole and install other fasteners nearby.