Ways to loosen bolts, screws or headless screws
A car has many parts connected to each other with screws, bolts and screws. It is quite common to find situations where the head of a bolt or the splines on a screw, screw. Therefore, the question of how to unscrew a bolt or screw with a slipped edge is relevant to many car enthusiasts.
Slipping is the blurring of a screw or screwdriver face on the head of a screw, bolt, or self-tapping screw. Both a master and a beginner can encounter such a problem. When a screw has flattened edges, a spanner starts to slip on it, and you won’t be able to unscrew such an element. Screws and screws can have damaged splines on the head, which also causes the screwdriver to twist and you can’t unscrew the damaged fastener.
Reasons why the splines of a screw, screw or edges of a bolt, nut may be slipping:
If during the unscrewing process the wrench or screwdriver slips, don’t panic and try to find out the reason. Sometimes it’s enough to change a screwdriver or wrench, and the problem is solved immediately.
Ways of unscrewing screws, bolts and screws with flattened edges
If you didn’t manage to unscrew the fasteners, which have slit edges, you can use one of several proven options.
Gas wrench
This method is used when unscrewing bolts because the head of the bolt protrudes and can be caught. To do this:
- Clean the bolt head.
- Lubricate the connection place with kerosene or diesel fuel, WD-40 type fluid helps a lot, and leave it for 15-20 minutes.
- Unscrew the bolt. Do it with a gas wrench. It makes a big effort and get a good grip even with a round head.
The disadvantage of this method is that it is not always possible to get a gas wrench to the right bolt.
Cutting a new edge
If it is a large screw, you can use an angle grinder to cut new faces on it. It is enough to make them only 4 and with a smaller wrench unscrew the bolt. It is possible to cut a new edge on the bolt with a file, but this is harder and longer. A cut can be made in the head of the screw or screw with a metal saw or angle grinder.
A hammer and chisel or impact screwdriver
This option is better suited for sagging nuts or screws that are large enough. The chisel is placed against the head of the fastener, and the screw or nut is gradually turned by hitting it with a hammer. Small screws or screws can be unscrewed with an impact screwdriver and hammer. After loosening the fastener, the work is done with an ordinary screwdriver.
Tourniquet or a piece of rubber
In this case, use a small piece of medical tape or a piece of dense rubber. The material you have chosen should be placed on top of the screw or screw head, and then pressed down with the screwdriver, gradually turning it. Having a rubber band will help to increase friction and solve the problem.
Extractor
The extractor is a special tool that is used for removing dropping screws, bolts or screws that have had their heads pulled off or broken.
An extractor is a tool for unscrewing screws, bolts, or screws with stripped or broken heads
- Use a thin drill bit to make a small hole in the head. In some cases you can simply hammer the extractor into the slotted slot of the screw.
- Select an extractor of the desired diameter. Hammer or screw it into the prepared hole. This depends on whether a conventional or screw tool is used.
- Torque the bolt.
Regular or left-handed drill bit
Left-handed drill bits with counterclockwise rotation are commercially available. They improve the alignment of the tool and reduce the load on the drill bit, which gives better performance and accuracy of drilling. Insert such a tool into the drill and you can unscrew a screw or screw with a flattened head. If you don’t have a left-handed drill bit, you can try to drill out a jammed fastener with an ordinary drill bit. In this case, take a drill bit with a diameter smaller than the diameter of the bolt or screw. Be careful not to have to cut the threads for the new fastener later.
Fix the nut of the appropriate diameter to the head of the problem screw or screw using epoxy or cold welding adhesive. After the glue has firmly attached it, use a wrench to turn the nut and unscrew the screw or screw along with it.
Welding
If there is a welder nearby, a new nut can be fastened to the head of the screw or bolt by welding it on. After that it can be immediately unscrewed.
Solder and soldering iron
If you need to unscrew a small screw or bolt, use a soldering iron and solder:
- Drop the heated solder on the head of the fastener with bevelled edges.
- Before the tin hardens, a screwdriver is inserted and waits a few minutes.
Why do screws come off??
Despite the mass of advantages, threaded connections have one significant disadvantage: bolts often break quite often
In an industry such as the automotive industry, threaded joints are used very widely. Almost all car parts are assembled by threading. Despite the even greater simplicity and cheapness of welding, it can not completely displace the thread, because the latter has the ability to quickly disassemble the structure.
When a bolt breaks, there are situations when part of it remains in the hole and it is quite problematic to remove it from there
This article considers the question of how to get the remainder of a torn bolt out of a threaded hole, using the example of working with a car cylinder block.
The top part of a torn off bolt and its head can often be taken out of the threaded hole, because 90% of the time, bolts break in the threading direction
There are few reasons why bolts break. The main one is the excessive force when tightening. Using long-handled wrenches you can apply enormous forces to the bolts that will eventually exceed the yield strength and the bolt will simply collapse at its weakest point. Most often, it is the first third of the thread length, starting from the bolt head.
When assembling some machines, it is not only important to select the correct bolts for threads and grade, but also to screw them in with the correct torque. And it should be no more or less than what is stated in the assembly instructions. Usually, a bolt is tightened until it stops and then it is tightened again.
The tightening force is measured in newtons per meter or kilogram-force per meter (the old-fashioned way). As it often happens, craftsmen might not have a spanner they need and use what they have at hand.
It is quite possible that a hypothetical bolt, for example with M8 thread, could be tightened with a wrench with a nominal torque of 3.A bolt with a torque of 8 kgf m, will be tightened with a torque of 4 kgf m. This can cause the bolt to break. Even a 5% difference in tightening torque often results in broken bolts.
If you put the bolt against the engine, you can see that it came off exactly above the cylinder block, that is, there is thread residue in both the block and the head
The lower part of the bolt stays in the structure. At the same time, since the thread is already in its original place and the bolt is simply screwed in, it could be in both parts being screwed together.
That is, even disassembly of the entire structure could not remove the remains of the bolt. The only possible solution in such a situation is to extract the broken thread in some other way.
One must realize that when removing the bolt there is no way to damage the internal thread of the body, otherwise you won’t be able to screw anything else into the hole.
Ways you can unscrew screws
There are several ways to unscrew a broken bolt. Let us see them in detail.
With the top of the bolt and the head
When it is deformed, a kind of “tendrils” are formed on it, which can be used to catch the rest of the bolt in the hole
The easiest way to unscrew a bolt that is broken but well lubricated when tightening is to use the top part of the bolt that is already broken off.
The chance of success with this method is small, but it is worth a try, especially if the bolt comes off in the initial phase of tightening.
Using a small screwdriver or chisel
You can try to unscrew the remains of the bolt by using a screwdriver or a small-sized chisel. there are two ways to do this: either just unscrew the broken part using the irregularities in the area of the break, or make some sort of small slit on the top side of the broken part, clinging to the edges of which to unscrew.
The last method is feasible only if the material used for the chisel or screwdriver is of higher strength than the material from which the bolt was made.
Using an extractor
The extractor is a drill bit with a long cone-shaped tip
It’s the most effective way, because you can almost always get results with it. The peculiarity of extractors is that they are screwed into a hole located in the central part of the bolt to be unscrewed. The thread on the extractor has the opposite direction of the bolt‘s thread (i.e.н. “left-hand thread”).
There are usually several bits of different diameters in the sets that are sold
They all have the same shape, with a rectangular mount for a drill or tap on the other side relative to the tapered thread.
When screwing into the bolt, the extractor unlocks it and, at a certain point, stops it. A further rotating movement is transmitted through the extractor to the bolt and unscrews it.
Let’s look at the sequence of actions to be performed in order to unscrew a stripped bolt with an extractor.
Drilling out the rest of the bolt
It is recommended to make a bushing of small length, from the outer part of which to cut a thread with the same pitch as the thread of the hole, into which the broken off bolt was screwed
First you must make a hole in the remains of the broken bolt. It is a difficult operation because the diameter of the bolt is relatively small. You also have to be very careful not to damage the threads when drilling.
Two drill bits with different shaped tips are used. a blunt angle and a sharp angle
In the center of the sleeve it is necessary to make a hole, sufficient for the passage of the drill, which will drill out the remains of the bolt.
Unfortunately, this method is not always applicable, because it requires a lathe to be on hand. Therefore, another method is used.
The first is used to align the top of the bolt remnants, and the second is used directly to drill the hole for the extractor. The diameter of the drill bit with the blunt tip should be slightly less than the diameter of the threaded hole. The diameter of the second drill should be equal to the diameter of the extractor.
Screwing on the extractor
Pliers are not desirable, as they will cause the rectangular face of the extractor to “stick”
Then everything is simple. an extractor of the appropriate diameter is screwed into the obtained hole. This should also be done carefully, with as little speed as possible. It is necessary to use the correct tool for screwing in the extractor (a tap or a special attachment to the drill with a square section), so as not to spoil its attachment on the opposite side.
As a last resort, it is possible to weld a nut of an appropriate size to the end of the extractor to make the unscrewing of the bolt with an ordinary wrench
Then the extractor is screwed into the bolt and rotated in it until it stops.
Broken bolt below the surface
Complicated problem, especially with soft metal parts. Therefore, it is very important to unscrew the broken bolt without damaging the thread in the hole. The procedure here is as follows:
- The center of the metal part is marked with a core. It is best to use a thin and strong metal tool, it will not damage the product;
- Then a tap is purchased that has a reverse thread. Its diameter should be smaller than the diameter of the bolt;
- A not very deep hole is drilled under the tap;
- The tool is installed to cut the thread. Turns in a circle and then the element can be unscrewed.
If the last point could not be carried out, the tool can become directly a bolt. However, do not exert excessive force, as there is a chance of breaking it. As a result, the old broken part can be removed and new elements can be screwed in.
Using an extractor
However, the surest option that will help to unscrew the broken bolt is to use a special tool for this operation. It is called an extractor, and it is sold in a set of tools with different diameters. It looks similar to a tap, but it has no longitudinal slots and a tapered notch for threading.
You can use the extractor after drilling a hole in the center with a diameter that will allow the tool to go in for several turns. Turn it all the way in and then all the way out.
So, here are a few ways to unscrew broken bolt elements. Each should be applied depending on the complexity of the breakage and the availability of the proper tools. But the most practical and best option is to buy a set of extractors. They are quite practical and allow you to work on bolt parts of different sizes and with all types of threads.
Be sure to treat the surfaces, this will avoid unnecessary contact and contamination. Successful work on the unscrewing of broken bolt joints, because the full operation of the whole mechanism depends on it, especially for cars! Learn more about how to unscrew the broken off bolt elements with a video on specialized websites or forums!
How to unscrew a broken bolt with your own hands using special tools or improvised means
To unscrew a broken bolt with your own hands, you can do it in a variety of difficult ways. Choose the one that is most suitable in your case according to the availability of the right tools.
Important! In many cases you will have to drill holes in the center of the broken bolt. In order not to damage the thread of the bolt hole, the drill bit has to be positioned exactly in the direction of the central axis. Special sleeves and pilot drill bits are good for centering.
How to remove a broken bolt with an extractor
This is a specialized tool for removing damaged fasteners from holes. Therefore, the question of how to unscrew a broken bolt with an extractor will be answered first.
To unscrew a broken bolt with an extractor, proceed as follows.
Drill a hole of the required diameter in the scrap.
Turn the tool counter-clockwise and remove the broken bolt.
How to use a screwdriver to remove the broken bolt
This method is often used to unscrew screws that are flush with the surface or at a shallow depth. Proceed as follows.
Drill a few holes and connect them. You will get a recess for the screwdriver.
Insert the tool into it and unscrew the broken bolt.
How to remove the broken screw with another screw
Large diameter bolts can be removed with this method. There is no risk of damaging the threads.
Drill a threaded hole in the center of the broken bolt.
It will unscrew the splinter as it is tightened.
How to unscrew a broken bolt with welding
There are four ways to unscrew a broken bolt with a screwdriver. Which one is right for you depends on the nature of the breakage.
If a piece of hardware is sticking out, weld a nut to it. Unscrew the splinter with a wrench.
If the bolt broke flush with the surface, weld a washer (with a hole smaller than the bolt diameter on the inside of the hole) to the wreckage, and a nut to the washer. Unscrew the item with a wrench.
To unscrew a bolt that is slightly broken, the splinter can be extended directly by welding. Then a nut or metal strip is welded to it. To remove the chip, use a wrench or pliers.
If a thin bolt is broken at great depth, you will not be able to unscrew it with welding. If a thick piece of metal is broken, you can weld a metal tube to it (the electrode is inserted into the hole in the tube).
How to unscrew a broken bolt with the help of improvised means available
To drill out a broken bolt with one of these tools, proceed as follows.
Drill a hole with a diameter a little smaller than the tool at hand in the broken piece.
Hammer the tool into the hole. This will loosen it.
How to drill out a broken bolt
This method of unscrewing broken bolts is used only in extreme cases (risk of damaging the threads) or when it is possible or necessary to cut a new one.
You will need left-handed metal drill bits to drill it out.
Drill the hole with the thin left drill bit.
Gradually increasing the diameter of the tools, drill out the bolt.
To avoid damaging the threads, carefully control the direction of drilling at all stages.
photo : drilling out the broken bolt
Bolt with torn edges
Now we will figure out how to unscrew a bolt with torn edges. As a rule, the causes of this misfortune lie in the fact that:
- The parts the bolt was holding were unnaturally dislocated. This will cause it to get jammed and ruined.
- The bolt itself was tightened too much when it was screwed in.
- The tool used to tighten it was the wrong size and improvised means were used (screwdrivers or chisels are often put in larger size wrenches in the absence of suitable smaller ones).
Before you can undo a broken bolt or nut, you must first make some preparations. This allows you to spend less time and effort, and sometimes saves expensive equipment.
The sequence of actions
- Coat the connection with a liquid that will help unscrew it. Such liquid can be the famous WD-40, brake fluid or kerosene. Take your time, let the fluid do its job. As practice shows, you can safely leave the part alone for thirty minutes or even an hour.
- Take any handy tool and lightly, not hard, tap the hardware on all available sides. Your goal in this case is not to run the bolt like a golf ball, but only to slightly loosen it in place of its attachment. There is a risk of damaging the threads while doing this activity, so be measured for force and swing.
- If possible and if there is space, try to heat the bolt. For this purpose a gas torch is suitable. Make sure there are no flammable liquids or objects near your work place. Also make sure before you start warming up, that in case of an emergency you have somewhere to retreat to. Do not heat the part with an open flame in an enclosed space. It is better to open the gate or move the bolt into the air. Rust and fat burned off in this way will turn to ash and will no longer prevent you from unscrewing the bolt.
But it often happens that a screw gets jammed if there is no way to reach it with a torch or tapping tool. In this difficult case, you should angle grinder or any handy tool like a chisel to make on the retained flat of the deep cut. It will be the hook that allows you to pull the whole bolt out.
Now you can catch on this ledge and try to unscrew the unyielding screw. Press the screwdriver into the notch, and, making light hammer strokes on its handle in the unscrewing direction (not clockwise), slowly twist the bolt.
Hexagonal bolt
The axle facets are convenient for both screwing and unscrewing. Clear and flat, they give you a firm footing for the key. If the screw is suitable for your hand and of the appropriate size, you can comfortably twist it by hand at first, pulling it up later with a tool. However, it is not uncommon when, due to overuse of the screw itself, or high loads on the connection, the edges are torn off and the fastener remains sticking out in the joint. It is uncomfortable to grasp, it slips out of your hands and tools. Let’s look at a few solutions to this problem, with appropriate remedies.
- Make a notch on the head of the bolt by any available method. However, when making this notch, there is one important point. The walls of this notch must be vertical, with no slope. Otherwise the tool that you will then rest in the notch will simply slip over the flat. And in this case there is a great danger of damaging not only the tools, but also the hands of the master.
- Use special so-called extractors for screws with torn edges. Extractors have threads cut in the direction that is directly opposite to the threads of the bolt itself. Thus, when the hole is drilled in the bolt and the extractor is inserted, it is fixed tightly in the bolt and will not rotate when unscrewing such bolt with pliers.
- Use left-hand reverse drill bit and reverse drill. The idea is to make a hole in the fastener with a regular drill, put the left drill bit in it and use the reverse of the drill to unscrew the stuck bolt.
- Find a suitable TORX bit. The ideal sprocket should not go through the slot in the hex hole, but should not be too big for the hex. The TORX star will cut through the flat of the bolt with its slits, locking tightly on the head. You can now work the screw firmly. Proceed with care, because in this case there is a great danger of tearing the TORX drive sprocket slots.
The screw with a hexagon hole can be unscrewed as follows:
- It is necessary to take a file and make it to the size of the hexagonal key. You save a lot of money by making this cut, because you can use the fastener more than once in the future.
- Make a notch on the flat with an angle grinder or any other suitable method, for example, a hacksaw for metal. And use a flat-blade screwdriver, resting on its handle as a pivot point.
- You can also use one of the appropriate sized TORX star sprockets to unscrew the screw.
For connecting rod bolts made of steel, there are only two ways:
- Use an extractor. Properly selected extractor and your careful actions will help not only to unscrew the screw, but also to do it without significant damage to the tool.
- Call in the help of an electric welder. Use an electric welder to reattach any hexagonal socket to the torn-off fastener that you don’t need anymore. Welded in this way, it becomes a new head for the screw. It will be convenient to hold and unscrew. But unfortunately, this method can be used only and exclusively for parts made of steel. Unfortunately, this convenient method cannot be used with screws made of other materials.
How to cut a stud with a thread?
Dt is simple enough. It is necessary to screw a nut onto the bolt before cutting. Then clamp the bolt in a vise and cut off the excess with a metal hacksaw (by the way, you can also use an angle grinder). after that the bolt is taken from the vice and the nut is unscrewed from it.
The nuances of using the cutting-off wheels when working with a screwdriver
The rotation speed of a screwdriver is much lower than that of an angle grinder, which means you don’t have to worry about the disk breaking. Another thing is that exactly the low RPM contributes to fast wearing of the disk. In addition, to get to hard-to-reach places with a big wheel is not always possible, which means it is better to have a small stock of “soap”.
When cutting metal with a screwdriver, you should not neglect personal protective equipment, such as goggles. The fact is that precisely because of the low speed and rapid abrasion of the cutting wheel, a huge amount of abrasive dust will fly in the air. But that is not what is most dangerous. Particles of wire reinforced with a cutting wheel are much more dangerous if they get in the eye.
Using a screwdriver to cut studs and bolts
When a situation arises where several bolts need to be cut quickly and no angle grinder is handy, a screwdriver can be of invaluable service. Of course, you can use a metal saw, but this work is very time-consuming. It is best to combine these two tools, and now we will look at how to do it.
Preparing the screws for cutting
To begin with, mark the required length of the bolt with a marker. Then two nuts are screwed on the bolt so that they are on the side of the cap from the risk. One of them is aligned with the groove, and the other is set so that it acts as a lock nut. Then the bolt is clamped into the screwdriver chuck by the thread, which is superfluous.
Cut the bolt with a screwdriver
A metal hacksaw is used as a cutting blade. It is held in place (good if it is possible to fix the blade). The screwdriver turned bolt is leaned against the blade and trimmed fairly quickly. The nuts play another important role in this. After sawing, a little damage to the thread is inevitable. Now, when you unscrew the nut, it recovers.
What to do when nothing helps or the thread of the bolt connection is badly damaged?
Drill a larger diameter hole and cut a new thread.
If the broken part is hardened and the drill doesn’t pick it up, you can try heating it to red and then let it cool slowly. Never refrigerate with water or any other method! You can heat it by welding or using a torch. This heating and cooling down should be done several times. Thus, the metal will temper and become softer. Then you can try to drill it out. It is not advisable to heat it until it is red in the aluminum casing. There is a possibility of warping of the housing where it is heated or it melts.
What to do if the extractor, drill bit, or hexagon is broken?
You can etch it out with nitric acid. One condition is that the body into which the shattered part is screwed must be made of an aluminum alloy. Nitric acid is one of the strongest acids. It dissolves metals well, but does not attack aluminum. The chemical reaction takes several hours, about 10-24 hours, depending on the properties of the steel, the diameter of the splinter, and the ambient temperature. Nitric acid must be diluted with water before use. For example, 57% acid is diluted with water in the ratio of 1:1. That is, the acid must be diluted to 30-35%. Nitric acid is a chemical reaction that reconstitutes the nitric acid and destroys the metal at the same time.
Nitric acid is poisonous, so be careful when using it and take care not to inhale its fumes.