How the nut is tightened. How to protect threaded connections from unscrewing. Why is a rusty nut hard to unscrew?

A nut that is rusty and therefore unwilling to unscrew is a problem that is not uncommon for motorists, locksmiths, plumbers, and cyclists. The part is stuck in place as if tightly. To stir it up, sometimes it takes too much time and effort. We will introduce you to several ways that will tell you how to unscrew a rusty nut quickly and with a minimum of effort.

Why is a rusty nut hard to unscrew?

As a result of the interaction of metal with oxygen in a humid environment, corrosion characteristic of it appears on the material - rust. During its formation, there is a multiple increase in the volume of the oxidation product (the same rust). The nut "swollen" in this way almost tightly merges with the bolt. With a little miscalculation of the forces, you can easily break the bolt, trying to break this alliance.

But rust is far from the only reason a nut won't loosen:

• Pollution. If dirt, dust, small metal chips are entangled on the surface of the thread, then this becomes an obstacle to unscrewing the nut and jamming it in one place.
• Strong puff. A tightly screwed nut is also the cause of a stalemate. The heavily tightened metal of the surfaces of two parts, a bolt and a nut, sticks to the neighboring one, which leads to the fact that it is very difficult to unscrew the element.
• Poor quality tool. The case may be in the same wrench, the edges of which are ground off, deformed or otherwise damaged.

Choosing the Right Tool

To successfully unscrew a rusted nut, you first need to assemble the tools that will help you in this matter:

• Throw key.
• Socket wrench.
• Collared heads.
• Mechanical wrench.

Do not try to move a tightly jammed nut with force! Such an impact will only lead to stripping of the thread, cutting off the faceted part, and often even to breakage of the tool. First of all, you need to help the cause with the help of a hex wrench. wrench should not be applied.

About safety

Before removing a rusted nut, read these important safety points:

• Do not use an instrument that is damaged in any way.
• Unscrewing the nut is always carried out counterclockwise.
• The tool on the part must be securely fixed.
• Use special household gloves to avoid injury.

So, if the nut is rusty, how to unscrew it? We offer you several effective methods.

Method number 1: dissolving rust

How to unscrew a rusted nut? We will not suffer with the tool, wasting our strength in vain. And let's go in search of a substance that will help dissolve rust and reduce friction. Of the most famous, they have proven themselves well:

• Special WD-40.
• Kerosene.
• Brake fluid.
• Petrol.
• Carburetor cleaner.
• Alcohol.
• Table vinegar.
• "Coca-Cola" and another drink containing inorganic phosphoric acid.

We are sure that at least one of the above was at your fingertips. Further, the algorithm of your actions is simple:

1. Wet the nut well with the product. Wait about half an hour.
2. After that, try to carefully unscrew the part with the tool. It didn’t work out - again processing with a substance and wait.
3. The tool will work better if you soak a rag or napkin in it and wrap it around the nut.
4. You can then speed up the unscrewing by lightly tapping the part with a hammer.
5. Another effective method- after exposure to the solution, try to twist the nut with a strong and sharp jerk.
6. For a small nut, the "rocking" method - back and forth will help.

Method number 2: heating

When the nut is rusted, what will help to unscrew if the previous method is ineffective? Try to heat the part - due to high temperature the metal will begin to expand, thereby destroying the layers of rust. The threaded connection from this, in turn, will lose strength.

What can be used as a heater:

• Gas burner.
• Lighter.
• Building hair dryer.
• Blowtorch.

In extreme cases, ordinary boiling water will help you. Be careful not to use the heater in close proximity to wood or painted elements.

The instructions for your actions are as follows:

1. Heat the nut to a high temperature - preferably red hot.
2. The next step is to try to unscrew it with a key.
3. If the nut or bolt thread is damaged, it is necessary to weld the end head to the nut, and then heat up the entire structure. Try turning it off with a wrench.

Method number 3: destruction of the nut

Sometimes the question "How to unscrew a rusted nut?" there is only one answer - to destroy it. It will help you in this matter:

• Chisel.
• Bulgarian.
• Hacksaw for metal.
• Electric drill.

And here is the algorithm of actions:

• Using a chisel and hammer, prepare grooves along the edges of the nut. The further you drive in the chisel, the larger the diameter of the part increases. The result of this will be the destruction of the connection held on the thread. You will achieve a similar effect by drilling such holes with an electric drill. This case is handy if you have enough room to access the nut.
• Another way is to use a grinder or a hacksaw for metal. You need to carefully saw the part along the axis of the bolt connected to it.

Method number 4: twisting

The logic is simple: if the nut cannot be unscrewed in reverse side, then maybe try to move it along the thread in the other direction? As soon as the part succumbs to your efforts, you need to try to slowly but surely turn it in the necessary direction.

Method number 5: tapping the nut

How to unscrew a rusty nut on a faucet? Any plumber will advise you to tap it.

For these purposes, a small 100-gram hammer will serve as an ideal tool:

• Apply light blows alternately on each of the faces. Moving in a circle, go through this path several times.
• During your actions, microcracks will form in the rusted metal, which will lead to both deformation and destruction of the corrosion layer.

In no case do not try to hit the jammed nut harder! This will not only not speed up the process, but will also lead to deformation of the edges of the element, bending of the bolt, or even breakage of the part that fastens this design.

Method number 6: wax cup

Rusted nut - how to unscrew? Another way: from plasticine or wax, mold a shape resembling a mini-cup. At the same time, its sides in height should be a few millimeters higher than the edges of the nut. Pour sulfuric acid into the "cup" and put a small particle of zinc. You will cause the effect of the so-called galvanic cell: the acid will destroy rust, and the zinc will help the iron cations to recover. As a result, the nut can be unscrewed without damaging the part with acid.

Problem Prevention

In order not to suffer in the future on how to unscrew a rusted nut on a car, bicycle, mixer, when installing this part, do not forget to do the following:

• Be sure to treat the thread with grease: graphite, silicone, teflon.
• Refuse to use grease and lithol. The fact is that these substances are perfect only for dynamic, moving parts, but not static ones, which include a bolt with a nut. In our case, such a lubricant will only stiffen and, conversely, will interfere with unscrewing.

We hope that you found a suitable method that helped you deal with the problem. Once again, we draw your attention: do not forget about its prevention!

Many will agree that loosening a hub nut is one of those activities that can be punished in judicial order, it’s too inconvenient, hard even for a physically strong person with all the necessary set of tools. However, since it is not always possible to choose the easiest one (Option One, he is also the Chief!) - sending the car to the service station, where they will not only unscrew it, but also make subsequent repairs. Then you will have to deal with the task on your own, and using the easiest and most effective way possible.

In which direction does the hub nut turn off

Yes, you may very well be one of the lucky ones who won't need any extra effort, as the problem with loosening the nut may simply be choosing the wrong direction.

So, we take a knob and, when your car is far from new, try, if the nut is not locked, on the left wheel, unscrew the nut counterclockwise, and on the right wheel, clockwise. In modern brands, it is usually necessary both on the left and on the right unscrew the hub counterclockwise.

Before you start unscrewing the hub nut, do not forget that it breaks down when the car is on wheels, and stops are placed under them. On the side from which the nut will be unscrewed, the stop is securely installed.

Although if the nut is located deep, and the brake disc is ventilated, then you can try to unscrew it (by fixing it with a powerful screwdriver) and so, only after making sure that the car is securely secured. Remember about personal safety precautions: protect your eyes, do not be too zealous, because in courage and enthusiasm you can accidentally get hurt or ruin the car body.

Unfortunately, in most cases it is not enough to use a knob with a large lever, you have to use additional tools, special blends. Let's consider other options.

Easiest way to unscrew/break the hub nut

Most the easy way can be considered the following, but it assumes complete replacement nuts. Do not worry, any method does not guarantee the safety of this part. To get the hubs off the ground (an option for all brands - from VAZ to foreign cars, where there is a groove on the shaft), you need to take:

Unscrewing the VAZ hub nut with a drill

• New nut.
• Drill or screwdriver.
• Drill up to 3 mm.
• Chisel.
• Hammer.

Process.

1. You need to drill the nut along the groove for re-locking.
2. With the help of a chisel and a hammer, simply break the nut and remove it with subsequent replacement.
3. If it is not possible to throw away the nut, then you will have to sweat - and in the truest sense of the word, too.

But this method should be used only as a last resort, first try using more or less simple and humane methods.

How to loosen a hub nut - the delicate way

What do you need:

• Tubular socket wrench - "knob". The tool must be made of high strength steel.
• Powerful screwdriver.
• Iron pipe.
• WD-40.
• Metal brush.

Process.

1. We clean the thread from dirt using a brush with metal bristles. Now saturate the hub nut with penetrating grease. For example, WD-40.
2. We impregnate the hub with a penetrating mixture. You can take a break for 10-15 minutes, and then you should put the head of the key on the nut and hit it with a hammer several times, gradually increasing the force of impact. Just do not overdo it: the point of this action is to make a slight deformation of the nut, due to this it will be easier to remove it. And immediately after the blows, you should try to unscrew the hub nut on a VAZ or a car of another brand.

Remove the nut from the car: force method

What do you need:

• Lever from a pipe (length not less than one and a half meters).
• Powerful socket wrench (450 mm.).
• Head of appropriate size.

Process.

We put the head of the key on the hub nut, insert the knob and put the pipe on the handle. Gradually increasing the applied efforts, we turn off the part.

As experienced car enthusiasts say, few hub nut can resist for a long time if you use a “Zilovsky” balloon!

How to unscrew a broken bolt

What to do, how and how to unscrew if a stud or bolt is torn off. Video tips on how to independently unscrew a torn bolt / stud in an engine or manifold. A reliable way to unscrew if you tore off the bolt head

Replacing the rear wheel bearing VAZ 2111

To replace the rear wheel bearing on VAZ 2110, 2111, 2112 cars, you will need: a head for "30", keys for "10" and "15", a hammer, platypuses and a long pipe as a lever. Look closely at the nuances

Unscrewing the hub nut on the VAZ: "burn, beat and twist!"

Now consider the methods that can be the only effective in your case, but from this they are no less radical, even barbaric.

Strong hammer blows

You hit the hub - you hit the bearing! If you make a replacement, then - go ahead! If you value, avoid this method.

Burner use

The law of physics is guaranteed to work, and the body (read: hub nut) will expand. And this will greatly facilitate the removal of a stubborn part. There is one “but”: not only this one part is heated, but everything else, in the area of ​​​​the burner. For example, a bearing. And it is better not to allow this. As a more gentle option, we can suggest using a soldering iron and ... patience. You will need it.

Jumping on the lever

A chisel will help break the hub nut

The "method" is fraught with the danger of an unexpected breakdown of the edges of the nut, breakage of the key, and so on. Just don't do it.

Take a chisel, make notches on the edges

An increase in diameter, of course, makes the hub nut unsuitable for further use, but it will be easy to unscrew it.

Himichim

Now let's look at ways for those who do not rely on the help of physics, but want to solve the problem with the help of chemistry. Your laboratory should have: kerosene, white spirit, acidified sulfuric acid, zinc, plasticine, hammer, water, sandpaper, wrench, chisel.

Attributes of the chemical method of unscrewing the nut

Process.

With kerosene (experienced people recommend making a mixture of White Spirit and kerosene), we wet the nut and bolt, applying a swab to them, no matter whether it is cotton or gauze. After some time - from an hour to a day, and with repeated attempts, you may find that the hub nut can be easily unscrewed. But even here you can’t do without strength: at a minimum, you will probably have to work with sandpaper to clean the parts from rust. If after that it still doesn’t work, you should help with a hammer: tap it on the edges of the hub nut.

If in this case you have not succeeded, make a small container of plasticine, fasten it on top of the hub nut, pour water with sulfuric acid into it, put zinc in the container. Begins chemical reaction which handles rust very well. Usually a day is enough for even neglected corrosion to release the part. Finish the job wrench. But this method is valid only if the reason is that the nut is firmly stuck and / or rusted, and if it was simply overtightened, neglecting the required tightening torque (in order to “sure”), then you just need to screw it.

What is the result..

As you can see, unscrewing the hub nut is not an easy task, but it is completely solvable. Note that it is worth trying to save the hub nut first by using a penetrating fluid such as a bucket. The physical effort to twist the hub should be moderate. And, of course, you should refrain from strong blows and burning with a burner, as ways that can render not only the nut, but also the bearing unusable.

By correctly determining with what force to tighten the hub nut and stopping in time, you can avoid stripping the thread and the need to carry out costly repairs, given today's prices for nuts. Masters perform this work using a special torque wrench. Since the wheel bearing is a rather capricious product and additional equipment is not always at hand, it is very important to know the answer to this question.

Before work, it does not interfere with determining what kind of it is installed, for example, it can be conical or roller.

Features of tightening the hub nut

Not understanding with what force to tighten the wheel nuts, it is better not to undertake this work. If they are tightened, then a breakdown will occur, and if not held out, then in this case, scrolling may occur, the seat under the bearing will deteriorate. Anyone who is not sure of their knowledge can use the spring cantor, but you can get by with more in a simple way. Ratchet wrenches most often cannot provide sufficient force, and the tools designed for this are expensive.

To prevent breakage and do the job correctly, it is recommended to use a lever a meter long or a little more for pulling. If a small thread pitch on a car hub can take a force of 20 Nm, plus it will be necessary to turn the key another 90 °, in total such efforts will give a very decent tightening torque.

Who remembers physics can make a simple calculation. To do this, you need to know your weight and the length of the lever. A value of 20 Nm is equal to a force of two kilograms with a lever length of a meter.

The force, then with what moment to tighten the hub nut, depends on the individual characteristics vehicle. Tightening recommendations for even the same bearing often vary. They depend on the quality of the metal of the hubs, the strength of the nuts, pins, threads. Usually 19-23 kgf/m is sufficient. If the bearing weakens and the gap reaches a value of 0.06-0.08 millimeters, this will significantly affect the reduction in the resource of the entire mechanism.

Specialists who have worked in a car service for many years recommend tightening the hub nuts every 15-20 thousand kilometers.

It will be useful in this case to relax them a little by one or two turns. It is best to have the car jacked up while doing this. To carry out this process, many advise using a tubular wrench, a ring wrench, because it has thick walls and there is a place for a knob, and it is more powerful. Thanks to a special adapter, it will be possible to use a pipe.

Modern cars are equipped with compression nuts that do not need to be countersunk. They have belts and they themselves will be pressed into the grooves of the trunnion. No need to press on the key with all your weight of one hundred kilograms, it is actually twice as strong as necessary. Knowing exactly what is the tightening torque of the hub nut it is possible to avoid losing a wheel on the way, before that a knock will occur when cornering, while the car may fly into a ditch.

Responsibility of the moment.

How to tighten nuts and bolts

Lever torque wrench. Simple, cheap, reliable.

Well, the repair is entering the final stage - it's time to start assembling. How are nuts and bolts usually tightened? "From the heart"! One will pull up, and then another foot will rest against something - to "tightly". Another will put a pipe on the key, and insert a crowbar into it ...

In fact, all fasteners are designed to be tightened with a strictly defined force - in technology it is called a moment. Not less than necessary (or it really will unscrew), but not large (you will tear off the thread) ... But where is it - this golden mean? A torque wrench will tell you - it will measure and show you the magnitude of the moment-force. And those keys that are the most modern will also “prompt” aloud when enough is enough.

The oldest torque wrenches are equipped with a round scale and a mechanism similar to a watch. In them, when a bolt or nut is tightened, a thick steel rod is twisted, and very slightly. The gear reducer magnifies this tiny movement many times over, and the pointer on the scale rotates just enough for the mechanic to gauge the force applied to the fastener. This device does not differ in particular accuracy, especially not new: as the mechanism wears out, the gaps in the gears and their axes cause backlash of the arrow, and sometimes jamming.

Later they came up with a simpler tool. A rod of a strictly defined rigidity and length is attached to the base of the square key (for a hexagonal head). And at the other end is a pen with a scale.

This ancient tool has survived over a hundred engine repairs. One of its advantages is compactness.

An arrow is attached to the square. When the mechanic tightens the nut, the rod bends, and the arrow, always fixed relative to the square, shows the force on the scale that has shifted along with the end of the rod. This is a very simple and cheap tool. And if the manufacturer exactly withstood the manufacturing technology, then the most reliable one. From old age, the rod can be deformed - the arrow in the free state will not point to zero. To restore accuracy to the device, bend the arrow - it is made of mild steel.

The most modern, sophisticated torque wrenches are more likely to be used in specialized workshops or on a factory assembly line. They have a scale that vaguely resembles a micrometer scale, and, guided by it, you can very accurately set the required force. When it is reached, there will be a loud click, and the hand will feel a return. So, with this nut finished - it's time to move on to the next one. Such a tool is very convenient if, for example, you need to pull off the crankcase halves - tighten 20-25 bolts with the same force. With less monotonous work, it is tedious to rebuild the device for “your” force for each nut - here it is more convenient to use a simpler tool.

Micrometer scale

With what force to tighten the fasteners - this can be found in the repair instructions. Do not rely on your own experience and do not try to use "someone else's" documentation. Even on motorcycles of similar design, fasteners for identical assemblies should be tightened with different forces (see Table 2). It may differ several times! If suddenly you do not find recommendations, then the nut or bolt is standard, and they must be tightened with a standardized force (see Table 1).

For complex parts tightened with many bolts, the instructions provide a diagram showing the tightening sequence. If it is not observed, it is possible to warp the entire assembly, a leak will form or some shaft will jam. There are several bolts, and the sequence of their fastening is not indicated? So, they need to be tightened crosswise. And gradually, in several steps, until the torque wrench shows the right moment.

Modern torque wrench

When reading the tightening torque table, pay attention to the notes. They may contain special assembly conditions. For example, that the threads should be lubricated with oil or thread sealant before tightening ... If there are no additional requirements, then it is understood that the fastener parts must be clean and dry. And preferably neither strongly chilled nor hot - at room temperature.

Two dowel pins are located on the top plane of the cylinder block. The cylinder head dowel pins are located on the second and fourth threaded holes on the left side of the cylinder block (when viewed from the front) and are "flexible" dowel pins. The interference between the dowel pins and the cylinder block is 0.053-0.203 mm. The dowel pin and cylinder head are assembled with a transitional fit, with a clearance of 0.016 - 0.084 mm.

Check the cylinder head gasket, which should be smooth and clean, free of burrs and scratches. Install the cylinder head gasket on the flat surface of the cylinder block with the dowel pins so that the part number is on top.

Wipe the contact surface of the combustion chambers of the cylinder head, the upper plane of the cylinder block and the threaded holes. There must be no accumulation of oil at the bottom of the threaded holes of the cylinder block, otherwise this may lead to cracks in the cylinder block.

Install the cylinder head bolt washers on the bolts with the chamfer up and the other smooth surface towards the cylinder head. Next, insert the bolts into the holes in the cylinder head, and then pre-tighten 3/4 turn.

The cylinder head bolts are hand-tightened four times in the order shown in the figure.

Tighten the bolts one by one to 20 - 25 Nm.

1. Tighten the bolts one by one to 40 - 45 Nm.

2. Turn the bolts 90 degrees in the same sequence.

3. Turn the bolts 90 degrees again in the same sequence.