How to unscrew the disc from an angle grinder. Let’s dwell in more detail on cutting discs

How to remove the disc from the angle grinder without a key

When working on any machinery, you should always expect abnormal situations that cannot always be solved according to the manufacturer’s recommendations. The angle grinder is no exception. You may experience excessive clamping of the cutting disc during operation. This problem is particularly common with large, high-powered models, over 2 kW. What to do if the disc on the angle grinder is jammed or the nut does not unscrew? This is dealt with below.

It is difficult to encounter this problem when rotating at idle speed. Especially when working with lightweight wheels and tools with soft-start function. But after increasing the RPM and coming into contact with the surface to be cut, the following happens:

  • If there is resistance from the material, the wheel’s rotational angular velocity is severely reduced and the wheel is braked.
  • The motor continues to run for a few moments at the same speed due to inertia, dragging the gearbox and spindle behind it.
  • The retention nut is tightened by inertia on the threads of the spindle head, thereby pressing the cutting disc in.

That’s it, the tightening of the locking flange is over. you’ve got a nuisance situation on your face. The following factors influence its occurrence:

  • Large wheel size.
  • High power of the tool.
  • Massiveness of the rotor.
  • A sharp increase in cutting depth, t.е. Increase in resistance.

In this case, remove the disc from the angle grinder is very difficult. Additional measures have to be taken.

What is the cause of the malfunction?

Before you wonder how to remove the disk from the angle grinder, experts recommend to understand why the angle grinder bites the nut. It has been observed that this problem is predominantly seen in angle grinders, which have a large disc size. A disc over 18 cm is considered large. In the course of operation torque is formed. Then, when the master starts cutting, there is a slight impact. In other words, the disc is subjected to force. If the size of the nozzle is no more than 12 cm, then this impact will be negligible. If the disk is large, the nut is tightened more by inertia. As a result, it is not possible to remove it in the usual way. information on how to remove the disc from the angle grinder, told below.

Bitten disc, how to remove the clamping

You can loosen a tightened threaded joint by warming the pressure nut by rubbing it against a wooden surface of a thick bar or a sawed tree stump in the countryside. Unlike heating with a blowtorch or gas torch, it is possible to adjust the clamping pressure of the nut on the wood. The more even heating of the threaded joint over a few minutes makes this method less safe in terms of preserving the performance of the angle grinder. In practice, as shown in the following video, the clamping nut is easily unscrewed when the temperature reaches the point where a drop of water instantly evaporates after it hits the surface of the friction-heated clamping nut with the angle grinder.

How to set the disk correctly, whether it is necessary to tighten

During operation of the angle grinder, the clamping device that presses down on the disc tends to tighten even more. Therefore, when installing a new consumable, you should just give it a gentle squeeze. Then the laws of physics will ensure that he securely clamp the tool.

How To Free Up An Angle Grinder Disc That’s REALLY Stuck

How you can easily unscrew the disc of angle grinder, not having the right skills

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When the economy comes to unscrewing angle grinder disks, so many owners find themselves in a very unpleasant situation. It turns out that to do it is not so difficult. Often the problem lies in the banal lack of appropriate knowledge and skills on the subject. The fact is that this process is much more tricky than it may seem. What do you need to know to make it as easy as possible.

The problem lies in the clamping nut for the angle grinder. In the vast majority of cases, it is too tight and uncomfortable to operate. You need such a thing mainly in order to ensure the safety of the worker and those who may be close to him. However, this turns any disc replacement into a real “quest”. No one wants to have to deal with a nut every time they change a disk. Experienced masters know what to do to forget about such problems once and for all.

So, first of all, you need to use a lubricant when working with the jam nut. The best is any silicone grease. Thoroughly cure a nut before unscrewing it and leave it in this state for 5-7 minutes. When the waiting period is over, unscrewing the fixing element of the structure will be several times easier.

Secondly, while the nut will be removed, it is worth doing something else with it. You need to sharpen its two sides by 1.5-2 mm. This can be done with a file. The most important thing in this matter is not to overdo it. So we work slowly and very carefully. It is necessary to do this in order to facilitate subsequent procedures for tightening-unscrewing the nut. After upgrading, you can use an ordinary 36 mm wrench for this purpose.

Finally, you can simply buy and install a more convenient nut on the angle grinder. It is best to take one that is immediately combined with a washer.

If you want to know even more interesting things, it is worth reading about how to make the angle grinder was able to saw concrete without dust clouds.

How to change a disc on an angle grinder? Step-by-step instructions

To work with the angle grinder you must first install, and then, if necessary, change the disk on the angle grinder.

Often with this fairly simple procedure for some beginners and not only beginners can have all sorts of difficulties.

Below are detailed instructions on how to replace the disc on an angle grinder.

To change the disk on the angle grinder it is necessary to unscrew the fixing washer.

The fixing washer, as a rule, comes with special grooves, and you can unscrew it only with the appropriate wrench, which is usually included in the set of each angle grinder.


unscrew, disc, angle, grinder, detail, cutting

On some angle grinders as fasteners are installed conventional nuts, which can be unscrewed with a wrench.

To unscrew the locking washer, the slot in the washer must be filled with an angle grinder.

On the other side of the angle grinder, press the locking button to lock the rotor in place.

Next you need to turn the wrench counterclockwise.

So unscrew the fasteners, then replace the old disc with a new one.

After positioning the new disc in its place, first screw in the securing washer by hand, and then tighten it with the wrench.

After all the above-described manipulations angle grinder “loaded” with a new disc and you can get to work.

In the case where there is no special key, to remove the drive and replace it with a new one, you can use improvised means, namely to use a large screwdriver or its analogues, such as a blunt chisel or t.п.

The bottom line is as follows, set the end of the screwdriver in the slot for a special key in the direction of unscrewing, also fix the lock to disk did not rotate, and sharp not very strong but enough power strokes on the back of the screwdriver produce unscrewing disk. Read more in the article “How to unscrew the fastening nut on an angle grinder without a wrench?”.

Types of discs for angle grinders

the angle grinder is widely used in construction and repair operations. Discs for the angle grinder differ from each other:

The choice of discs for the angle grinder requires knowledge and consideration of not only the machined workpieces, but also the capabilities of the tool itself.

Cutting discs

The most used angle grinder discs, also called abrasive. They are classified according to different characteristics. There are discs for working with metal, stone, wood. There is also a diamond disk, which serves to work with the toughest and hardest materials (concrete, porcelain, tiles, marble, granite and other natural and artificial stones).

Let’s give a brief description of each type.

A common feature for all cutting discs is classification by outside diameter and thickness. The outer diameter comes in:

  • 115 mm for small domestic grinders;
  • 125 and 150 mm for medium power and weight angle grinder;
  • 180 and 230 mm for high-powered professional tools.

disc thickness ranges from 1 to 3.2 mm. It depends on the size of the nozzle: discs with large diameter have greater thickness; discs of medium and small diameter have any thickness. The choice of disc thickness is influenced by:

Cutting (abrasive) discs for metal

These wheels are used to work with sheet steel body (disk thickness from 1 to 1.6 mm) and long steel: rebar, round bar, channel, angle and other kinds (disk thickness from 2.5 to 3.6 mm). There are special attachments for working with stainless steel, aluminum, cast iron and other metals.

This is indicated by markings on the disc surface and a coloured stripe. Abrasive discs are several layers of fiberglass mesh, onto which a bakelite abrasive material (silicon carbide, corundum, electrocorundum) is pressed under high pressure from both sides. The reinforced abrasive discs are then placed in a furnace for heat treatment to harden. The set heating temperature is 200 degrees. There, the mass is sintered and becomes strong and resistant to splintering.

Abrasive blades for stone

They are absolutely identical to the discs for metal and differ only in the abrasives used.

For wood

They are made of high-strength steel and have sharp teeth on the outside diameter. These tools work like a circular saw and are quite dangerous to work with. It is recommended that the angle grinder is fixed in place with a special attachment.


They are used to cut high-strength materials of natural and artificial stone.

There are different kinds of diamond discs for concrete, reinforced concrete and stone. They are distinguished by a fraction of diamond dusting and a kind of cutting edge: continuous, with large or small cuts, or notches. It is important to know that the diamond disc is not used for metal work. It is hard to understand the function of a diamond disc by its appearance. The best option is to consult a sales assistant or carefully study the package leaflet before buying.

Some manufacturers of diamond discs paint the front side with paint, depending on the material for which they are designed:

  • green. for granite;
  • Yellow. for plaster and tile;
  • blue. for marble and concrete;
  • gray. for granite ceramic and tile;
  • orange. for brick.

Diamond disc with segmented cutting blade is used for dry cutting of stones. The solid cutting edge discs require water cooling. Turbodiscs with slots in the body of the wheel operate at higher rotational speeds than discs with a segmented blade.

Grinding and Roughing

Grinding wheels are divided into four types:

    Petal (emery) wheels remove old paint, primer or varnish, and sand wood.

  • Special wire wheels remove rust and stubborn dirt.
  • Diamond modifications in the form of a bowl polish stone products.
  • Discs of plastic or rubber are used to polish metal surfaces. Replaceable discs with sandpaper, felt, sponge, cloth can be attached to the discs.

Most grinding discs work with special pastes or liquids that include the finest abrasives. They are used for sanding surfaces of all materials, including auto bodywork at car repair shops.


If you had to use a gas wrench, you must remember about the very powerful arm of such a wrench and the force applied to the parts of the “angle grinder”. If you are not careful, you could break the spindle lock or damage the gearbox.

All manipulations with the disc of the angle grinder must be performed with the power supply completely disconnected (the plug must be taken out of the socket). Any unintentional pressing of the start button will cause the electric motor to start, and the rotation speed of the rod is very high. Injuries in this case can not be avoided.

Working with an angle grinder involves a lot of waste in the form of metal or wood shavings and dust. Wear safety glasses before you start: they will protect your eyes from splinters of the cutting wheel itself if it jams or destroys.

The safety glasses are not only a safety feature. If your eyes are protected, you can pay more attention to the actual operation of the angle grinder, ensuring the correct cut or choice of the correct operating mode. This allows the most efficient use of consumables (cutting-off wheels) and minimizes the risk of disc jamming or crushing.

A protective mask that completely covers the face is an excellent substitute for glasses. it is especially important for a visually impaired craftsman who wears dioptric glasses on which protective goggles cannot be worn.

The blade on the angle grinder can be mounted “on its own” or “on its own”, depending on the direction of rotation and, therefore, the chip flow. In work it does not make any basic difference. However, the “angle grinder” with the wheel “on itself” tends to pop out of the cut forwards when the disc is jammed, and not towards the person using it. This is especially important when working with powerful tools, but even a small angle grinder can be a serious hazard.

A properly installed extension cord with a socket, preferably without grounding, can help you quickly stop the machine from jumping out of control.

“Angle grinder” is a coarse tool and one should not strive to get an ideal surface as a result of its work, the main thing is to make a rough cut, which later, if necessary, can be processed in other ways.

To work without clamps and jamming it is better not to cut long metal workpieces to the end, leaving 1-2 mm of metal in the cut: they will be easy to break off afterwards, it will have practically no effect on the quality of the workpiece.

It is better to place small workpieces in a vise or clamp them to a workbench or other reliable horizontal surface. Both cutting quality and safety depend on a firm grip.

To change the disc on the angle grinder you need to unscrew the mounting washer.

Fixing the washer, as a rule, comes with special grooves, and you can unscrew it only with the appropriate wrench, which usually comes with every angle grinder.

On some angle grinder as a fixing set of conventional nuts, which can be unscrewed with a wrench.

To unscrew the fixing washer, an angle grinder wrench must be installed in its grooves.

On the other side of the angle grinder, you should press the locking button to lock the rotor in a stationary state.

Next turn the spanner counter-clockwise.

unscrew, disc, angle, grinder, detail, cutting

This is how you unscrew the fasteners, then replace the old disk with a new one.

After installing the new disc in place, first hand screw in the securing washer, and finally it is tightened with the wrench.

The angle grinder is now “charged” with a new disc and you can start working.

Bottom line

There is no problem with idle rotation of the cutting wheel, especially if the wheel is relatively light and the tool has a soft start function.

After the speed has been reached, the next chain of events occurs the moment the cutting wheel comes into contact with the surface to be grinded:

  • The disc, encountering enormous resistance from the material to be machined, loses speed, i.e. slows down.
  • The motor rotor keeps turning for the first few moments at the same speed and pulls the gearwheels, which pull the spindle along with them.
  • The thread of the spindle head is screwed harder into the retainer nut, which is pressed into the cutting wheel.

Everything, there is an emergency situation (excessive tightening of the corkscrew nut), which is caused by the following factors

  • Large diameter of cutting discs.
  • The high power of the electric motor.
  • Massive rotor.
  • Great depth of cut (working load).

Unscrewing the nut that secures the cutting disc is now difficult.

Locksmith tip: How to unwind an angle grinder if the disk is jammed and torn

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On the one hand, an angle grinder. the tool is not very tricky. On the other hand, more attention is required. The worst thing that can happen during work is that the disc will jam and break. The worst thing is that in this situation it is very difficult to extract the blade. Especially if you don’t know how and what to do to solve a spontaneous problem.

What you need: Hammer, pliers, WD-40 grease, thin screwdriver

If the disc torn in the angle grinder and jammed the locking nut, then to the deepest regret of the owner to solve the problem with “jewelry” ways will not work. The work ahead is rough and painstaking, but not too difficult. After you have everything you need, you need to take pliers and start using the most barbaric (but the only effective method) way to break out the ripped disk from its working area. It is best to remove the blade in small pieces.

When the bulk of the disk has been removed, you need to do finer work and carefully remove all the debris from under the retaining nut. Rip out all with only the pliers will not work, but you should remove as many pieces as possible. Immediately after that you must take a shovel, clamp it in a vise. Apply the angle grinder so that the edge of the shovel cleared the slot in which there are fragments of the disk. The angle grinder is turned on at the lowest speed.

How to use a Cutting Disc with an Angle Grinder

As a more elegant alternative to the shovel rib, you can use a suitable piece of sheet metal and an ordinary screwdriver. If it does not give way, you can grease it with WD-40. In addition, you can simply try to unscrew the retainer nut. To do this you will need to heat it up. The easiest way to do this is by leaning it against a tree and turning the tool on for a couple of minutes. The heated nut should easily yield to the standard wrench. It goes without saying that a torn disk still has to be broken out before you do it.