Many different threaded fastener types have been created over the years and are often used to combine two or more pieces.
In this article, the term “bolt” will be used to refer to essentially all forms of metal fasteners. Keep reading to learn how to remove a broken bolt.
In a perfect world, every bolt that needs to be removed would pop out with a bit of pressure. Sadly, there can be difficult times.
A bolt that had previously been cooperative may now become resistant to unscrewing. Here, we’ll talk about the causes and how to prevent them.
Conditions that make it harder to remove some bolts
Before we show you how to draw a broken bolt, let’s discuss the circumstances in which some bolts are challenging to remove or unscrew:
1. Unfastened bolt
Most likely, this bolt was overtightened (over-tightened). The bolt’s threads or the accompanying hole’s threads, where it is installed, have become stripped.
Or the nut can be stripped and prevent the bolt from being removed. Although the bolt can be twisted, it will not release.
2. A rusted bolt
This bolt is most likely a component of a corroded assembly, such as an exhaust system component.
The bolt is stuck in place due to corrosion. By conventional means, it cannot be turned.
3. Sided bolt
The wrench’s flats have occasionally been rounded during attempts at disassembly. This typically happens when the incorrect size socket or wrench is used.
Almost every shop should have a good set of wrenches and other tools and supplies.
4. Broken bolt head
Occasionally, the worst-case scenario is when the bolt head has broken off, and you’re left with a rusted cylinder pin. Hopefully, there will be enough threads to make removal possible.
What circumstance makes it so difficult to remove a seized bolt?
When access to the bolt is particularly challenging, it may be impossible to remove a seized bolt. An illustration of this might be a starter motor fastener between your car’s fender and the engine’s side.
It could be difficult even to get a socket or wrench on this bolt. Additionally, it spins freely (when stripped) or not at all (when seized). Additionally, your struggle to remove the bolt has made its head rounded.
You probably won’t be able to get close to this bolt to remove it using the techniques discussed in this post if it was challenging to access it with a wrench in the first place. In this situation, you’ll need to take the car to a qualified mechanic to have it fixed.
However, if you have easy access to any problematic bolt, you may remove it using the methods below and a little sweat. Continue reading to find out how to get a broken bolt out.
A damaged or stripped bolt removal technique (the best method).
A stripped bolt often cannot be twisted or stripped further; it remains in place. If this applies to you and you are unsure how to remove a damaged bolt, you can use a pry bar to remove the bolt. Here’s how to go about it.
A tiny chisel or a sharp screwdriver is required. The tool’s blade should be placed where the bolt’s head meets the surface of the next workpiece.
Tap the sharpened edge into the space between the screw head and the workpiece with a hammer.
The screw should begin to emerge from the hole as you tap. It could be necessary to transfer the tool’s tip to the screw’s opposing side and repeat this process multiple times. Avoid wiping the device too firmly to avoid breaking the screw head.
To help lubricate the bolt in its hole once it has opened up, you should spray a little WD-40 (or a comparable penetrating oil) into the hole.
The lubricant will spread as you turn the bolt after applying it, making the subsequent step more straightforward.
Using WD-40 a couple of times, waiting five minutes between applications might help release a stubborn bolt.
To allow the screw to turn quickly, you might need to make the hole bigger. In this situation, try to pry the screw out by inserting the blade of a more considerable screwdriver into the opening.
It ought to begin to move. If you are successful, you might now be able to use needle-nose pliers to grab the bolt, twist it, and then release it.
How to take out a round or rusty bolt (4 methods)
Compared to the stripped bolt we discussed earlier, a corroded or rounded bolt seized in place will be much more challenging to remove. This section will show you how to draw a broken, rusty bolt.
Steel bolts used in cast iron or aluminum engine blocks can frequently rust to the point where removing them is very challenging.
The bolt and the material surrounding the threaded hole chemically connect due to the corrosion process and galvanic reactions.
The following disassembly methods aim to release the bolt by rupturing the chemical connection. A standard or socket wrench should be sufficient to turn the bolt if the bolt head is still in good hex form and condition.
Typically, a 6-point wrench will work best for this. The high points of the bolt head are grabbed by a 12-point socket or socket wrench, which may round the bolt head more quickly when held in position.
A different method of grasping the screw will be required if the head is rounded or fractured or if the screw is a stud with no charge.
Each of these grasping and removal techniques can remove a bolt. However, the majority are not equivalent to having the head in good condition.
1. Pinch pliers
Take hold of the bolt’s head or shank using a set of pressure pliers. Because they have more gripping power, giant pliers perform better than smaller ones. A longer tool will also provide you additional leverage.
Remember that pinch pliers tend to slip off the screw, which can cause it to shatter or gradually lose its diameter.
A more excellent gripping surface for the jaws can be created for larger screws by filing or grinding a pair of opposing planes on the screw shank.
If there is room, a socket wrench can be used to grasp and turn the screw in place of the jaws.
2. Tools that rotate
You can also use a rotary tool with a fine-grinding wheel to create a straight slit through the top of the damaged bolt to remove it.
You should be able to turn the bolt with a big screwdriver if the slot is broad enough and around 1/8′′ deep.
The ideal screwdrivers for this are those with square shanks (or those with hex flats close to the handle), as you may improve the screwdriver’s turning power by placing an open-end wrench on the hold.
3. Bolt extractor
Using an external bolt extractor tool is a very efficient technique to grab a broken bolt, nut, or stud.
These gadgets are reasonably priced and come from reputable manufacturers. These high-strength steel extractors have internal spiral teeth with a slight internal taper.
The extractor must be pounded firmly into position on a rounded bolt head or broken stud. It can then be turned with a cutting bar or a standard 3/8″ or 1/2″ ratchet.
To stop the grip bushing from rotating on the stud and rounding it off, gradually increase the torque applied.
4. Two-nut approach (if the bolt head is missing)
This method can occasionally be used if the bolt head is missing, but the threads are still present and in decent shape.
Use a fine wire brush to clean the lines. Apply a red, thixotropic methacrylate-based thread locker to the ropes.
Using two open-end wrenches, attach two nuts to the bolt’s end, and tighten them as firmly as possible.
As directed by the manufacturer, let the thread locker fully cure. You might be able to grasp and remove the corroded bolt with a regular pipe wrench if you have the new wrench surfaces.
Welding a nut onto the end of the bolt or stud is an alternative to this method. Naturally, performing this step requires a light arc welder and some welding expertise.
How to Prepare a Bolt for Removal in 4 Steps
We now have some additional preparation measures that can assist you in loosening a rusty bolt before applying a wrench to it now that you know how to remove a broken bolt.
Heat the damaged bolt for several minutes using a hand-held propane torch with a fine tip.
The heat can break the corrosion link between the bolt and the surrounding metal by expanding the connected components.
As previously mentioned, as soon as the heat is removed from the area, apply torque to release the bolt.
Using an open flame near a moving vehicle might be exceedingly risky. Make sure there is no fuel, oil, or grease where you are performing repairs, and make sure no car parts are being heated or welded close to fuel or brake lines.
Avoid using rubber or plastic brake hoses and fuel lines since they can catch fire quickly and have disastrous effects.
Keep a fire extinguisher on hand when using open flames for any reason in your garage or near your automobile. At the very least, ensure it is a class A, B, or C extinguisher.
A ball peen hammer should be used to strike the bolt’s exposed end. Strike hard and repeatedly.
This impact may break the corrosion bond that keeps the bolt from losing. Then attempt to remove the bolt as previously indicated.
3. Influence Wrench
If there is enough bolt head, attempt to remove it without a socket wrench using an impact wrench. The impact can frequently release an otherwise frozen bolt.
On a worn bolt head, an impact wrench’s force can move the socket without turning the bolt and further around the head, so you should be mindful of this.
Apply WD-40 or comparable penetrating oil to the metal at the points where the bolt enters the mating piece.
Give it a night to rest. Oil may sometimes penetrate corroded bolts, reducing the force needed to remove them.