A bolt is a piece of metal, shaped like a screw, used for holding steel beams in place. However, during construction, it is highly likely for bolts to break. It happens rarely, but the likelihood increases if work is being rushed, or is being done by an inexperienced worker. Therefore, it is necessary to understand how broken bolts can be removed using a bolt remover.
Method 1: Extracting Kit
There are dedicated bolt extraction kits available easily at hardware stores. These kits serve as an excellent bolt remover.
Position the sharp end of a nail on the center of the broken bolt, and strike using a hammer. This will mark the broken bolt’s center. This will enable you to drill through the bolt’s center without the risk of damaging the broken bolt’s grooves.
Now drill a hole through that mark in the bolt using the drill bit which is left handed. Left-handed drill bits have threading that runs in the opposite direction. Therefore you need to set your drill to rotate in reverse, so that the bit is driven into the bolt. Another reason for using a left-handed drill bit is that it will turn in the direction opposite that of the broken bolt. This will prevent the bolt from becoming tighter.
Hopefully, the left-handed bit will catch, and result in unscrewing the bolt enough so that it can be grabbed by a pair of pliers or vice grips and removed.
You need to ensure that you are using a drill bit of exactly the right size. There is a table included with the drill bits in the extracting kit, which specify the size of the bolt that each drill bit is meant for. If the drill bit used is too big, there is a large risk of the grooves of the bolt being damaged. If the drill bit used is too small, a weaker extractor will have to be used which will entail a high risk of breaking off in the middle of the procedure.
Insert the extracting bit of the right size into the hole that you’ve just made. Depending on the kind of extracting kit that you have bought, this bit will have two differently shaped ends. At one end the tip will be left handed and tapered. At the other end, there will be a T-handle head or a hex head. Given that the extractor itself is left-handed, it will insert into the bolt counterclockwise. Furthermore, considering that the extractor is tapered, it would be best to tap it using your hammer before you switch to a T-handle or socket.
Now the broken bolt can be removed. As the extractor is tightened, the end that is tapered will catch and torque forces will act on the bolt to loosen it once the extractor is fitting snuggly.
Continue to turn the extractor counterclockwise until the bolt is fully removed from where it was embedded.
You should not undertake this process in a rush. Otherwise you run the risk of damaging the bolt and causing it to get further stuck. You even run the risk of damaging the article from which it is being removed. It is also a good idea to use the extractor as gently as you can. They are made from hardened steel. Hence an extractor which has been broken off would be significantly harder to drill out.
You should remove all metal filings. During the entire process, it is highly likely that metal fillings would have come from the bolt. If you intend to use a new bolt for replacing the broken bolt, you need to remove all the shavings and fillings first. This can be easily accomplished by using either compressed air or a magnet.
In the method described above, you can also employ the use of a bolt remover fluid such as a penetrating lubricant. These fluids are excellent bolt removers and can make the bolt extraction process a lot easier.
Method 2: Welding
Position the sharp end of a nail on the center of the broken bolt and strike using a hammer. This will mark the broken bolt’s center.
Now drill a hole through that mark in the bolt. You should use a bit whose diameter is almost one-fourth the diameter of the bolt to drill it out. This extraction method is used for bolts that have become excessively rusted. Such bolts cannot be removed with an extractor. Consequently, there is no need to worry about the bolt being tightened using a right handed bit.
Now you need to screw on a hexagon shaped nut onto the broken bolt. Use any grooves of the bolt that remain exposed and then tighten the nut. The nut needs to be firmly attached but don’t screw it on completely. Leave it back by a half-turn. There needs to be a gap between it and the surface in which the bolt is fixed.
Now you need to weld the nut with the bolt. This weld will not take much time, but you shouldn’t attempt this if you are doing so for the first time. You should either have an experienced person do the welding or practice welding using other articles before attempting this.
You will have to be extremely careful if the surface in which the broken bolt has been embedded will melt and bond to the steel nut or bolt. Therefore this method is particularly effective when the surface in consideration is aluminium. Aluminium doesn’t easily weld with steel.
The bolt can now be removed. Once enough time has passed for the welding to have cooled, the hexagonal nut has now become the new bolt head and can be easily removed using a wrench or socket.
The weld, despite being quite strong, is not unbreakable. For bolts that have corroded to a great extent, it may be necessary to weld the nut back multiple times.
In order to try and break through the rust, try to slowly work the bolt backwards and forwards at the beginning. Once it begins to loosen up, continue to apply force in both directions but more in a counterclockwise direction so that it can be removed entirely.
If you don’t want to go through the hassle of the methods described above, WD-40 has a Specialist Penetrant Spray, designed specifically for loosening up rusted and broken bolts. It is extremely easy to use, as are all WD-40 products.