How to remove a broken bolt from a hole. Unscrewing a broken bolt or stud from the cylinder block and other elements: solving the problem. Drilling - a great opportunity to turn a bolt without edges

Quite often, when using such fasteners as a bolt, situations arise when the head of the product breaks off, and the hardware itself remains inside. In this case, it becomes necessary to remove this residue without damaging the threads so that the hole can be exploited further. Given this, the topic of how to unscrew a broken bolt is very popular and requires more detailed consideration.

Types of fractures

Typically, such fasteners break at the end of the thread, although there may be exceptions. As a result, the hardware itself can be deepened into the hole, protrude above the surface, or even level with it. Based on this, it is necessary to decide how to unscrew the broken bolt, paying attention to this very moment.

surface break

This type of breakage includes the option when part of the hardware protrudes above the surface. It can be assumed that such a problem is most easily solved without using radical measures. However, before any unscrewing of a broken bolt, it is worth treating the place with kerosene to eliminate carbon deposits and weaken the contact of the surfaces.

If the protrusion is quite large, then the easiest way is to use tools such as pliers, pliers or clamps, with which you can grab the part and unscrew it along the thread.
Some experts, answering the question of what to do if a bolt breaks, which sits very tightly in the hole, recommend using a welding machine. With it, you can weld a lever to the hardware, which as a result will allow you to get a large shoulder for rotational movement.
You can also use a drill with a diameter slightly smaller than the bolt itself. With a drill, a hole is made along the central axis of the bolt to the full depth. After that, the remains of the fastener are removed with a hook, trying to unscrew the thread from the very bottom.

Flush break

It is believed that this failure is the most difficult, since it is sometimes very difficult to determine the diameter of the hole, especially if the fastener has been cut. Therefore, in order to determine how to drill out a broken bolt of this type, it is first necessary to clean the surface by determining the gaps.

Quite often, the place of the cliff has very uneven shapes, which, with this arrangement, are very difficult to straighten. Drilling in this state will not work. That is why a core is first used, which prepares a place in the center for working with a drill.

Further steps, describing how to drill out a broken bolt, are described in the paragraph on surface breakage. After making a hole, the remnants of the thread are simply removed with a hook.

Cliff below the surface

Such damage is quite difficult, especially if the part itself is made of soft metal. Therefore, you need to solve the problem of how to unscrew the broken bolt and at the same time not damage the threads in the hole.

First of all, using a core, the center of the hardware is marked. In this case, it is best to use a thin tool made of durable metal so as not to accidentally damage the part.

The next step is to purchase a tap with a reverse thread. Its diameter should be less than that of the bolt itself.

After that, a hole for the tap is drilled in the hardware itself, but it is not deepened much. Next, just install the threading tool and turn it along the way, which will lead to twisting. If this does not happen, then the tool is used like a regular bolt, but you should not make too much effort so as not to break it.

Extractor

The most correct answer to the question of how to unscrew a broken bolt is the one in which they suggest using a tool specially designed for this. It is called an extractor and is sold as a set of products of different diameters. Outwardly, it resembles a tap, but without longitudinal slots and with a conical notch for cutting.

To use the extractor, it is enough to drill a hole in the center with a diameter that allows the tool to enter a few turns. Then they begin to turn it all the way, and then until it is completely unscrewed.

Conclusion

There are several options for recovering broken bolts from a hole that can be used for certain types of damage. However, it is best to purchase a set of extractors in advance, which can be considered the best tools for such tasks.

Car owners often face such a problem as a broken bolt. And it makes no difference whether this car is Russian or foreign. All machines are stressed and break down over time.

And when you start repairing your car, a new problem may appear - a broken bolt. And here's the problem, how to unscrew it and throw it away? After all, you need to unscrew the broken bolt as soon as possible and continue the repair.

Why does the bolt break?

The bolt breaks due to the fact that it is either rusted or stuck. The more years the car, the more "bad" bolts and the more difficult it will be to repair the car. Most often, old cars have rusty bolts due to the fact that they often come into contact with moisture.

Long-term use of the machine wears out all parts and bolts. For example, the undercarriage of a car is constantly in contact with moisture. Therefore, do not be surprised that something has rusted somewhere.

The best ways to remove bolts

In order to proceed to the very unscrewing of the bolts, it is necessary to carry out preparatory work before this, or rather, cleaning the place of work from all dirt and dust. And in this we will be helped by the indispensable "weed" (WD-40), well, or you can use engine oil.

In case none of this is available, just hit the bolt with a hammer or heat it. But be careful, you must not damage other elements.

What if the bolt breaks above the threaded surface?

Consider several options for solving the problem:

You can try to unscrew the bolt with pliers if you managed to "rip off" the threads of the bolt a little;

The next method involves the use of a hacksaw, grinder or chisel. The principle of operation is as follows - make a transverse hole for a screwdriver, then use the screwdriver itself to unscrew the bolt.

The third option will be associated with the use of a welding machine. Follow the instructions below: take a similar size bolt and weld it into the broken one. Use the wrench to unscrew the bolt, but do not overdo it. Glue can be used instead of welding, but there is a chance that the job will not be done, so use welding to be sure.

Bolt breaks off flush with or below surface

If you don't know exactly how your bolt broke off, then look on the Internet for photos of broken bolts and determine which one is similar to yours. Consider solutions on how to properly unscrew a broken bolt:

Take a drill with a thin drill, drill two or three or more thin holes in the body of the bolt. This is done in order to then combine them. Insert a screwdriver into the hole and unscrew the bolt fragment.

The second way involves more drastic measures. You will need: a drill, a tap, work experience and a lot of patience. Do the following: drill a hole in the center of the bolt itself. Then carefully you need to cut the left thread in it.

The moment you screw in a new bolt with a left-hand thread into the thread, as soon as you reach the end, the old bolt should begin to unscrew.

Bolt broke flush with the surface

Be careful, there is a chance to damage the thread. Instructions for removing bolts without damaging the threads:

Drill a hole in the center (use a thin drill);
Replace the thin drill with a thick one and drill more;
When the base of the bolt is almost gone, and the walls become very thin, then try to break the remnants of the thread. Use a thin sharpened wire or tweezers for this.
If you did everything right, then you will not have to cut a new thread or "drive" the old one.
If you have an "extractor" with a left-hand thread, then you can use it. Unscrew the rest of the debris.

If you can’t unscrew the broken bolt in any way, and even no method helped, leave this problem. It is better to trust a person who has already encountered such problems and knows from experience how and what to do.

Note!

In no case do not complicate your work and do not act in haste, this will entail other problems. We hope this article was helpful to you.

Note!

Basically, each repair does not go smoothly, but with the occurrence of small problems, the elimination of which takes time and effort. What to do in a situation where you need to disassemble the structure, and the bolt is rusted or damaged, we will analyze further.

At home, not every master will have the necessary equipment at hand, but this problem can be dealt with with improvised means.

How to unscrew a broken bolt?

Main methods:

Clean the surface with a metal brush and treat with diesel fuel or kerosene. Trying to unscrew the nut with a wrench. Although there is no absolute guarantee that it will unscrew.
With the help of a chisel and a hammer, strikes in the direction of unscrewing. This method is not suitable for a small nut.
A gas wrench with a powerful clamp is a good tool in this situation. It is easy for them to grab even round objects, but heavier in hard-to-reach places. The longer the handle, the easier it is to unscrew operations.
When fasteners with a large size and it is difficult to unscrew it, it is possible to apply a metal coating using welding equipment and prepare the desired turnkey shape with a file.
A hole is cut with a drill inside the body of the fastener, an L-shaped rod is threaded through it, which will serve as a handle, and removed.

When there is enough space to use an adjustable wrench or pliers, this is good, but what to do in other situations?

How to unscrew a bolt with a hex or asterisk head

To extract an element use gas wrench with a compression of the part, they make a cut on the hat with a grinder and unscrew it with a screwdriver, an extractor of the appropriate size, special tools (a wrench, a stud driver), which are beneficial to purchase only if you have to deal with such problems quite often.

A TORX sprocket is selected in size (it should not be large and slots should go into the hole for the hexagon). It is inserted tightly into the cap and the bolt is unscrewed with a jerk to avoid breaking the sprocket slots. When driving stars with holes in the center, they break off, so it is not recommended to use them.

In any construction and auto shop extractor kits for sale. Outwardly, this device has the form of a metal rod with a conical thread on the left side and a faceted base on the right. With their help, unscrew the nuts with torn edges. To do this, a hole is drilled strictly in the center of the bolt, an extractor of the desired size is hammered into it and unscrewed with pliers. This is done simply and quickly, because the extractor has the opposite cut.

A drill with a reverse is an irreplaceable thing. Make a hole at the bolt with a thin drill. Take a left-hand drill with a smaller diameter and drill out the damaged bolt in reverse rotation mode.

If the bolt head is broken off

In this case, you need to be patient and choose the appropriate course of action.

Three ways:

A hole is drilled 3 cm smaller than the diameter of the bolt and a tap with a left-hand thread is screwed into it until the broken part begins to unscrew.
If part of the bolt protrudes, then a cut can be made on it with a grinder under a slotted screwdriver and proceed to unscrewing.
A hole is made in the base, into which the extractor is screwed counterclockwise. Then the damaged element is removed with a key.

The process takes a few minutes, but there are countersunk head products under the hexagon, the edges of which are easily torn off. Torx of a suitable size will help to cope with such a problem.

How to drill out a broken bolt

Professionals advise using a small diameter drill and making sure that it does not tilt to the sides when working. When buying, you need to focus on the country of origin and cost. High-quality drills cannot be cheap, sharpened in a special way and made of hardened steel.

Unscrewing nuts and bolts produce slowly and consistently, in this case it is impossible to rush, otherwise unforeseen problems will arise later and the loss of time to eliminate them. For example, many auto repairers are in a hurry to unscrew rusty bolts that break. It takes a lot of time to fix bugs. Therefore, it is necessary to plan the course of action immediately. How to deal with rusty bolts, we will discuss further.

How to loosen a stuck bolt

Often, car repair is complicated due to the presence of corrosion and oxidation of fasteners. For example, at the factory, during assembly, the master did not treat the thread with lubricants, and during operation water got into it. As a result, the bolt stuck, it would seem, tightly, but such a nuisance can be dealt with in several ways.

Loosen a rusted bolt or nut by tapping

When tapping with a bolt remove rust and scale, so it becomes easier to unscrew it. The operation is carried out with a hammer, turning with a special tool in order to create a torque. With caution, as you can damage the product and have to drill it. After removing the fastener, it is cleaned of rust and treated with graphite grease. If available, put anther on the connection.

With solvents

In the arsenal of any experienced car enthusiast there is always a set of liquids to combat rust and other plaque. Mostly use WD-40 with good penetrating ability into micro gaps, the cost of which starts from 100 rubles. Along with it, brake fluid, white spirit, kerosene, Coca-Cola are used. Unlike WD-40, other liquids have a weaker effect, and it is better to pour them into a container and place the boiled compound in it for greater effect.

If the bolt is stuck on the front pillar, the solvent can be carefully poured into the "glass". The main thing is not to damage the rubber bands on the racks, otherwise you will have to change them.

Moisten a rag with any means, wrap the nut and leave for a while. Then the bolt is tapped to destroy the softened rust and proceed to unscrewing.

thermal method

When the solvent does not do the job, you can try exposure to fire and cold. Any major auto or hardware store sells a gas burner that heats the bolt to a bright orange color. Then they cool it with engine oil and try to loosen it. If the attempt fails, the process is repeated anew.

This method does not always help, and when close to the paintwork, the fuel tank is very dangerous. When working with a gas burner, you must follow the fire safety rules and do not use it if you do not have a fire extinguisher at hand.

Freeze sprays are used to save the bolt for later use. But such reagents are mainly used by professionals, since in domestic conditions this business is costly and unprofitable.

How to unscrew a licked bolt

When scrolling the bolt, it is hooked with a nail puller and pulled out to the maximum possible height, left in tension and gradually unscrewed with a key. When a nail puller is not available, a screwdriver can be used. A small bolt is removed with wire cutters by the head. If it does not lend itself immediately, then rotate it, clamping it with pliers counterclockwise with an upward force.

Use tap, insert it all the way. If it is not at hand, then a screwdriver with a cone-shaped edge will do, which is carefully hammered all the way and they try to unscrew it.

To prevent such situations from recurring, they must be treated with graphite grease before tightening the bolts. But solid oil or lithol is not used for this purpose, because they are used for rubbing parts, and after lubrication, bolted joints are wedged.

Among detachable connections, threaded connections take first place both in terms of prevalence and reliability. However, in practice there are many cases when unscrewing a threaded pair is not easy.

The reasons why it is not possible to unscrew the stuck nut (bolt).

There are several reasons why it may be difficult or even impossible to disassemble this simplest connection:

deformation of the thread or connection details, for example, with a strong impact;
twisting not along the thread with the application of significant force - in this case, friction between the surfaces of the parts increases significantly (the effect may be aggravated due to the influence of external factors);
oxidation of the surfaces of the connection parts, the formation of a layer of rust on them;
diffusion of materials between the details of the connection.

The last two reasons are well known to almost everyone, especially motorists.

The problem is that studs, bolts and nuts are most often made of carbon steel. With prolonged contact with water and oxygen in the air (for example, bolts on a wheel are constantly exposed to such an effect), these substances penetrate into the smallest gaps, including between the parts of a threaded connection. As a result, iron oxidizes, forming a layer of rust, which increases friction. It will take a huge effort to move the parts from their place (often the value exceeds the strength of the bolt, and it collapses).

Designers try to avoid such troubles by using parts with protective coatings or made of stainless steels for connections. But that doesn't always work either. If the bolt and nut are exposed to heat (muffler parts are an example), the protective coatings can be broken, corrosion processes are accelerated.

There is also a process of diffusion (mutual penetration) of materials, the parts form a monolith, which becomes difficult to disassemble (this phenomenon is often encountered by those who try to unscrew the bolt on the crankshaft).

How to unscrew a stuck bolt (nut) - the main methods.

To cope with this task, several methods are used. They can be roughly divided into

mechanical;
physical;
chemical.

mechanical methods.

These include methods that allow you to disassemble a threaded connection due to the application of mechanical forces:

the use of ring wrenches and sockets instead of open-end wrenches;
using leverage to increase effort;
impact with a variable direction of force;
accentuated impact (short-term application of significant effort or effort at certain points);
shock destruction of layers of oxides and rust.

An open-end wrench covers only three faces of a nut or bolt head. In addition, there is some gap between it and the edges. In this case, applying enough force to unscrew it can be a problem - the key can break off and “lick off” the edges. A box wrench or socket covers all edges, which allows you to apply more force.

To increase the effort, you can use the lever - increase the length of the handle. At the same time, there is a danger of licking the edges or destroying the fasteners. You can also damage those parts that were connected by a threaded pair.

Often, a change in direction helps to unscrew a stuck or rusted nut - before unscrewing the connection, they try to screw it up. The action of forces alternately in different directions destroys the layers of rust, giving way to the details of the connection.

An example of the application of short-term significant force is given by the method using a chisel and a hammer. A notch is made on the edge, a chisel is pressed into it (directing it in the direction of unscrewing the nut) and hit with a hammer. In this case, the force of impact is much greater than that which can be applied using a wrench. Since the impact is short-term, it cannot destroy the bolt.

Note! In this way, you can also unscrew the nut with torn edges. This is somewhat easier than trying to file new ones for a smaller key size.

Light tapping of the nut and/or bolt with a hammer will shake the entire structure and destroy the rust layer. It is only necessary to dose the impact force so as not to damage the parts, not to deform the thread. Although, as one of the methods for disassembling a “recalcitrant” connection, destruction of the nut with such blows is suitable. The only problem is that the threaded pair will have to be changed.

Physical methods.

Some of them are based on the physical properties of metals. Of these, only one is widely used - heating the parts of the connection. In this case, the material of the nut expands, the gap between it and the bolt increases, and it becomes easier to unscrew it. If you heat the entire structure, you can destroy the resulting rust, which will also give a positive result. Any source of heat should be used for this purpose - a powerful soldering iron, a building hair dryer, a blowtorch or other sources of open fire.

Important! It is dangerous to use an open flame near wood, combustible plastic or flammable liquids!

A good substitute for an open fire is electric heating. For this, a transformer (factory or home-made) with a secondary winding with a voltage of 1.1 - 1.5 V and a maximum current strength is suitable. Through copper cables and clamps, the secondary winding is closed to a bolt that must be unscrewed. Heating occurs, after which the transformer is turned off, the connection is dismantled.

Other physical methods use the method of wetting surfaces to reduce friction. For example, if you allow liquid to enter the space between the bolt and nut through the smallest channels, the friction between the threads will decrease and it will become easier to disassemble the pair.

From easily penetrating liquids, you can use those that are always at hand with the motorist:

brake fluid;
antifreeze;
kerosene;
gasoline;
diesel fuel.

The first two contain glycols and ethers - substances with great penetrating power. The rest are aliphatic hydrocarbons and have a similar effect.

The second group also includes such solvents as whitesprit and turpentine. All of them can be used to unscrew the stuck nut. The processes are somewhat different only in time.

The method is simple - wet a rag and put it on the stuck parts. Penetrating into gaps and pores, liquids lubricate surfaces and loosen rust layers. After some time (from half an hour to 3-4 hours), you can try to unwind the connection. If disassembly fails, repeat the process. You can speed it up with periodic light tapping.

These same fluids are the basis for "liquid keys" - special lubricants that are offered in car dealerships.

One of the most popular among motorists is WD-40, which includes mineral oil, white spirit and volatile gasoline. The effectiveness of such a "cocktail" has been tested in practice, it copes with rusted nuts in half an hour.

Note! If the nut is stuck not due to water ingress, but under the influence of temperatures, the effectiveness of WD-40 is significantly reduced.

Chemical methods.

Their action is based on the chemical destruction of rust formed between the parts of the connection. This requires that active chemicals get into the gaps between the bolt and nut.

Almost any acids are used for such processing of threaded joints:

sulfuric;
salt;
acetic;
lemon;
orthophosphoric, etc.

Sulfuric acid for battery electrolyte or hydrochloric acid for soldering radiators is used in this way:

a rim is organized around the nut or head of the plasticine bolt;
inside the resulting "capacity" make a few drops of acid;
a piece of zinc activates the process, creating a galvanic couple.

A day after the start of such processing, any connection is untwisted.

Weaker acids are less effective, either a significant amount or more time is required.

Note! Orthophosphoric acid is found in beverages such as Coca-Cola. That is why you can try to unscrew the nut with their help. But its concentration is low, the acid itself has low activity, so such treatment is effective only in "mild" cases.

If nothing helps.

If you still failed to unscrew the nut, the connection can be destroyed - cut off with a grinder.

Another method is to drill out the bolt with a drill.

But before resorting to such methods, you should evaluate all the consequences!

Video.

Sometimes during the repair process there are so old and “stuck” bolts that if you try to unscrew them, they will simply break. Accordingly, the question immediately arises of how to unscrew the remaining rod so as not to damage the parts connected by it.

A novice master may be frightened by such a seemingly hopeless situation, but do not be afraid: unscrewing a broken bolt is not so difficult.

To begin with, you should remember that if the bolt is tight and does not want to get out, then you do not need to do this through force. It is better to immediately fill it with an anti-corrosion liquid, for example, WD-40. Then tap the cap well with a hammer so that the liquid can penetrate deep into the thread. After a couple of minutes, the stuck bolt will be several times easier to get.

Even if you have already broken off the head, fill the bolt shaft with "weed" or penetrating lubricant - this will facilitate the process of its removal.

There are two types of bolt breakage: when the head breaks off, after the bolt has had time to leave the seat a little, or when the rest is below the surface.

When the rift was above the surface

In this case, dealing with the bolt is easier. Here are some of your options:

Grab the rod that is visible above the surface with pliers or pliers and try to unscrew it.
Take a center punch and set it at an angle to the edge of the bolt. With light hammer blows on the center punch, try to give the bolt a rotational motion. Sometimes such small efforts are enough for the rod to begin to twist.
Using a hacksaw, saw through a transverse hole for a flat screwdriver on a visible surface and try to unscrew it. You can also use a grinder or even a chisel for this.
Another option is to use welding or aggressive glue. Try to weld/glue another bolt to the rod and unscrew it already. It is also possible to weld, for example, an L-shaped hexagon or any other suitable handle that can be used as a stop.

If you are using welding, then do not try to unscrew the heated bolt immediately - let it cool. Remember: the metal expands when heated, so it will be impossible to get the heated bolt. Pour cold water over the welding area to speed up the cooling process.

If the bolt breaks below the surface

For the first method, you will need a drill with a very thin drill. The drill needs to drill three holes on the same plane, and then connect them in one line. This will create a hole for the screwdriver - now you just need to insert it into the homemade groove and unscrew it.
The second method is more complex and time consuming. It will require a drill, a tap and patience. Using a drill, you need to drill a hole in the center of the stuck bolt. Then, using a tap, carefully cut a left-hand thread in this hole. You will be driving a left-handed screw into this new thread. After the screw is fully tightened, the old bolt will begin to unscrew.
The rod can also be removed by drilling. This is the most time-consuming and dangerous method, as there is a risk of thread damage. For drilling, a drill with thin drills is used. To drill a hole in a high strength bolt, it is better to use a cobalt or pobedite drill.

A hole is drilled in the center with a thin drill. It is very important to drill the first hole exactly in the center so that there are no distortions during further work! The drill must not be overheated, so you need to drill at low speed and constantly cool it in water or oil.

After that, a thicker drill is taken, then the next one, and the whole process is repeated until there is practically nothing left of the core. A special extractor with a reverse thread can be driven into the resulting hole and the remnants of the rod can be unscrewed. If there is no extractor at hand, then it is necessary to drill out the inside as much as possible. And when the walls become thin enough, try to break them with tweezers or sharpened wire. Be very careful when carrying out this procedure so as not to strip the threads.

If it was not possible not to touch the thread, then you will have to cut a new one, and the new thread will be larger than the previous one. If the diameter of the previous bolt thread was M10, then the new thread will be at least M12 diameter.

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