Over the years, various forms of threaded fasteners have been designed, and they are mostly used to join two or more components. In this case, the term bolt refers to as many types of metal fastening devices as possible.
From a practical point of view, if everything goes perfectly well in a lifetime, every bolt that has to be removed only needs moderate coaxing. But there are challenging times. In such times, a bolt that has always been cooperative may not unscrew.
This article discusses 5 methods to remove a bolt that is stripped, rounded, rusted, or broken.
What Conditions Make Some Bolts Difficult to Remove?
Stripped Bolt
This is likely caused by over torquing. Either the threads of the bolt have stripped or a nut that is not moving may have hindered the bolt from being removed.
The fastener is rotatable but completely stuck.
Rounded Off Bolt
A particular removal attempt has rounded off the wrench flats. Most probably, a socket that is not the correct size was used. Good quality socket (and wrench) sets should be standard tools in every garage.
It seems that oil drain plugs being rounded off is too common an issue. This is normally the result of someone not having access to the appropriate-sized socket, so they use the next best thing instead.
Rusted Bolt
As an example, this bolt looks like it could be part of a rusted assembly like parts of the exhaust system. While the rust process can be detrimental, in this case, it has seized the bolt in place, preventing it from being unbolted with normal force.
Broken Bolt Head
Usually, the more unfortunate instance is having the bolt head break off, with you left looking at a rusty cylindrical pin for quite some time and not knowing what to do. If you’re lucky enough, there are enough threads that will allow you to unscrew it.
What Makes it Impossible to Remove a Seized Bolt?
An example of a impossible to remove bolt would be the starter motor bolts located between the side of the engine and the fender of the car. They are well known to be difficult obtain.
You might, barely, be able to fit a socket or wrench on the bolt. It either moves freely and it’s stripped or it doesn’t move at all and is seized. The bolt head, as a result of your struggle to recover it, has been rounded off.
If using a wrench to turn this bolt was difficult, then attempting to remove it using the techniques described in this article will most likely not work. In this case, you will have to take the vehicle to a qualified mechanic for specialized help.
However, if any of the offending bolts are within your reach, the techniques below in addition to some hard work, may make it possible to remove them.
How to Remove a Stripped Bolt?
Most of the time, a stripped bolt cannot be removed, although it can be turned. In this scenario, the bolt can be pried out with the following steps.
You will need a sharpened screwdriver or a small chisel. Place the tool blade at the intersection of the surface of the bolt and the head of the bolt that is hinged to the chassis. With a hammer, attempt to push the sharpened blade deeper into the area found between the bolt head and part.
While you are hitting the tool, the bolt ought to start to unthread from the hole. It may be necessary for you to reposition your tool’s point to the other side of the bolt head and repeat this procedure a few times. Remember not to hit the tool too forcefully as it could lead to breaking the bolt’s head off.
If a gap has formed, spraying some WD40 or equivalent penetrating oil into the gap will help with lubricating the bolt in its hole. After oiling, turning the bolt will help with spreading the lubricant in the next step. If the bolt does not turn easily, applying WD-40 and letting it loosen for five minutes will help soften it.
To loosen the bolt freely, you may need to open the gap further. If this is the case, insert a larger screw driver blade into the gap and try pulling the bolt out. If successful, you will be able to grab the bolt with vise-grip pliers, which will allow you to easily rotate and pull it out.
Steps For Removing A Stripped Bolt
Remove any Outside Rust
Use a wire brush to clean the surfaces of the head bolt cover so that the rusted iron debris is prevented from being lifted and enables you to hold the heads of the bolt more steadily. This will also assist in the progression of the slowly following step.
Penetrating Fluid
In ideal conditions, use a penetrating oil. It will reach and break down the internal gunky rust covering that is sealing the bolt. Afterwards, with a bit of patience and time of soaking, you may be able to remove the bolt in the easiest manner possible.
While this scenario is not impossible, it where everything would be ideal, but reality is harsh, and feels like there is a need via penetrating oil to, let us say, give after work bonuses to increase the chances of greater success to the remaining steps.
Screw In to Screw Out
You might be lucky if you have a tiny yet surprisingly effective bolt which by screwing the bolt heads from the outer side will allow you to remove it.
If you are heading towards being halfway stuck in a rut, go ahead and keep adding the penetrating oil and see the magic work from there.
Tapping the Bolt Head
A lightly sharp tap at the bolt head might break the rust’s bond with the bolt. This, however, is very tricky because too much force can break the threads, which makes it even harder to remove the bolt.
Use of a Propane Torch
Heating the bolt may allow for removal as it can expand and contract, subsequently loosening the bonds.
Use a Slightly Smaller Wrench
This will work if the head is rounded, and the opened wrench does not fit. Hammering a smaller wrench onto the bolt might tightly lock it and allow for loosening. Keep in mind, when the bolt is removed, removing the bolt from the wrench becomes another task.
How to Remove a Rusted or Rounded Off Bolt (4 Methods)
A rusted or rounded-off bolt that is deeply seated will be much more difficult to remove in comparison to the stripped bolt we discussed earlier.
The bolt may be so corroded that it is difficult to extract it from the aluminum or cast iron engine block. The screw becomes chemically bonded to the threaded hole because of corrosion and galvanic disintegration occurring over time.
All of the methods shown below will try to break the bond and remove the bolt. In case the bolt head is in good hexagonal shape, it is possible to grip it with a standard wrench or socket and turn it.
Generally speaking, a 6-point socket will give the best results. It is easier to grab the edges on the bolt head with a 12-point socket, which is also more likely to round off the head while it is stuck in place.
An alternate means of gripping a stud without a head, or one with a rounded or broken-off head, will be required. Although most of these gripping and removing methods will fail unless the head is in good condition, they will still be able to extract the bolt.
#1. Vise Grip Pliers.
Use a pair of vise-grip pliers to grab the head or bolt shank. Because larger vise grips can exert more grasping power, they tend to work better than smaller ones. Moreover, longer tools give you greater leverage.
Caution should be taken when using vise grips because they have a tendency to slip off the bolt, which can erode the bolt over time, causing it to decrease in diameter and ultimately break off.
For larger bolts, grinding or filing a pair of flats on the bolt shank can provide more surface area for the vise grips to hold onto, which results in better surface area for the grips.
A pipe wrench can replace the vise grips, provided that space allows for it to be used to grab the bolt and turn it.
#2. Rotary Tool.
A Dremel tool or any similar rotary tool can be used to etch a straight groove onto the bolt with thin grinding wheels. The groove needs to be wide enough for a large screwdriver to fit, and must be about an eighth of an inch deep.
The optimal tool for use here is a square shank screwdriver, or a screwdriver with shaft hexes, because the shaft can be gripped with a spanner to provide greater force.
#3. Bolt Extractor.
Using an external bolt extractor tool is precisely how to grip a stripped bolt, nut or stud, and many Irwin products accomplish this efficiently.
These sockets are made more robust than the standard grade steel pairs as they have internal spiral teeth for indenting and shrinking on the head.
To use these more robust finish grade screw extractors, the socket must be tapped into the head or stud until it does not move, after which a 1/2″ or 1/4″ ratchet or breaker bar can be attached for easier accessibility.
The bolt can be turned to tighten while ensuring to gradually increasing the torque to prevent the bolt from spinning and becoming engrained too deeply in the socket.
#4. Two Nut Method (if Bolt Head is Missing).
Threaded on the outside bolt with feeler gauges are easy to use here work every time. Gently clean the outside threads and ensure they are free of rust or oils. After the threads have been cleaned, coat them in Loctite Threadlocker 262.
Using two open-end wrenches, thread the bolt with two nuts on its end and tighten them together to a comfortable fit.
Loosening the corroded bolt could be easier with a conventional socket wrench due to the newly introduced wrench surfaces. Make sure to follow the manufacturer’s instructions on letting the Loctite set, allowing it to fully set.
This technique could also be achieved by using an arc welder to tack weld a nut on the stud or bolt end. This step does require a light-duty arc welder and some skill with welding.
4 Ways to Prepare a Bolt for Removal
There are some preparational steps that can assist you with easing a rusted bolt before you reach for your wrench, not just after.
Heat
Using an oxygen-acetylene or propane torch with a pencil thin tip, heat the butt end of the bolt for a couple of minutes. Expanding parts can help break the bolt due to the corrosion bond that exists between the bolt and the surrounding metal.
As soon as the heated portion of the bolt has cooled, apply the torque as described in the preceding steps, and the bolt should come off.
Warning
It is imperative not to be near open flames when dealing with an automobile, as it can pose a great risk. Ensuring that there are no leaks of grease, oil, or fuel within the vicinity and not heating or welding parts that can cause fuel and brake lines to ignite should always be practiced.
In particular, special Warnings need to be assigned with regards to plastic fuel lines and rubber break hoses since they could be melted causing massive damage in no time at all. Always have a Class A:B:C fire extinguisher close by when using open flames anywhere near an automobile or a garage.
Impact
While using A ball peen hammer, hit the bolt sharply several times. This force may be strong enough to break the corrosion bond which is preventing the bolt from being loosened. Once you have accomplished this, try and remove the bolt using the steps given above.
Impact Wrench
If there is enough of the bolt head present, instead of a socket wrench, use an impact wrench. The automatic system may allow for an otherwise frozen bolt to be released.
Remember that the power of the impact wrench will do nothing but round the bolt head further and spin the socket without turning for worn sockets.
Lubricant
Where the bolt passes into its associated hole, apply penetrating oil such as WD-40 to the surface. Let it sit overnight. In some cases where the corrosion on the fastener is extreme, the oil will allow it to be removed with less force.