How to change discs on an angle grinder. Remove the cutting wheel from the angle grinder with a chisel

How to change a disc on an angle grinder with a wrench?

Peorator or drill in the chisel mode Unscrew the disk on the angle grinder without a key you can use a drill or peorator, pre-set it in the chipping hammer mode. As a working tool is used a suitable auger, most often 6 millimeters.

To begin with an answer to a frequent question: “In what direction the nut is unscrewed on the angle grinder?” Remember! Unscrewing should be in the direction of rotation of the disc.

What is the cause of the malfunction?

Before you wonder how to remove the disk with an angle grinder, experts recommend to understand why the angle grinder bites the nut. It has been observed that this problem is predominantly observed in angle grinders, which have a significant disc size. A disc over 18 cm is considered large. During operation, torque is produced. Then, when the master begins to cut, a small bump occurs. In other words, force is applied to the disc. If the size of the nozzle is less than 12 cm, the impact is negligible. If the disk is large, then the nut by inertia tightens more. As a result, it cannot be removed in the usual manner. Read more about how to remove a disc from an angle grinder below.

Angle grinders

How to choose a wheel for an angle grinder

When choosing the right nozzle for the angle grinder, you need to pay attention to the following points:

  • Choose the required disc diameter (it must not exceed the maximum allowable size of the nozzle of a specific angle grinder model, which is limited by the size of the protective hood) and the area of its use. The name of the disc indicates the area of application: cutting, grinding, sharpening, etc. The type of blade can tell you what kind of material it will work with. But often manufacturers indicate the type of material with visible stripes of a certain color: green. concrete, blue. metal, and so on. Sometimes a clear symbol is put on the disc of the type of material for work on which the tool is designed.
  • Study the marking that is applied to the disc itself. It consists of numbers and letters of the Latin alphabet. The initial letters indicate the type of abrasive material: A. corundum; AS. electric corundum; C. silicon carbide. Next are the numbers indicating the grit size of the abrasive inclusions. This parameter affects the thickness of the material to be removed. Coarse (coarser to the touch) grit is used for non-ferrous metals. They work on soft surfaces with good performance. With fine-grained grinding wheels, workpieces of various steel grades are cut, roughened, and ground. The letters at the end of the disc indicate the hardness of the bond material. The hardness increases with the number of the letter. Important note: The softer the bonding material, the harder the material, the harder the nozzle can work with. Conversely, the harder the disc binder, the softer the workpiece material must be. The final part of the inscription consists of numbers indicating the maximum rotation speed. Its value is presented in revolutions/minute or meters/second.

Be sure to study the marking on the disk: here you will find all the necessary information

Heating the nut

There is another way that allows you to quickly dismantle a flange nut with an angle grinder. For example, if you can not unscrew the flange using a gas or specialized wrench, as well as a chisel, then it should be slightly heated. In this case, you can use an autogen or an ordinary burner, working on gas. Then, after the nut is heated, you must try to unscrew it with a wrench or chisel.

In this case, you need to wear gloves when dismantling the flange, so as not to get burned hands. It is worth noting that of all the previously proposed unconventional ways to replace the disk on the angle grinder, this is the most dangerous and risky. This is because there is a high risk of overheating the bearings and oil contained in the gearbox angle grinder when the flange gets hot.

To prevent the cutting wheel from jamming between the flanges, we recommend the use of special rubber washers. In an extreme case, such a washer can be made of thick cardboard or strong rubber. In addition, special quick-clamping nuts for angle grinders are available on the market. They can be easily unscrewed with bare hands without any wrenches or other hand tools during disk replacement.

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Only discs with diameters suitable for the power tool may be mounted on angle grinders. In this case, when dismounting the wheel, as well as during work with the angle grinder, the user must follow the safety rules established by the manufacturer of the device. It is strictly forbidden to remove the protective cover from the angle grinder, for the subsequent installation of a disk of large diameter. Selecting a replacement disc, it is recommended to pay attention to the indicators of the power level of the power tool, as well as the speed at which the spindle rotates.

Changing the disc as usual

Regularly operating the angle grinder, you must constantly change the discs, which are consumables. If the tool is no longer comfortable to work with, then the worn abrasive wheel must be replaced.

Important! Be sure to check the power supply is disconnected to prevent personal injury.

Step-by-step procedure

The disk is fixed on the spindle head by fixing nut with M14 thread. Standard feature is a wrench with special protrusions for engaging with the holes of the fixing flange.

To unscrew the nut you need to fix the spindle. For this purpose, there is a special retainer located on the back of the angle grinder. Pressing the button locks the gearbox in place with a cotter pin and prevents it from turning.

Insert the wrench into the holes. With one hand you hold the clamp and with the other you turn it counterclockwise with the wrench, sliding the nut.

The direction of travel of the disc is generally clockwise. However, there are models that may have a different. In any case unscrewing is in the opposite direction of rotation.

When the nut is loose, it can be effortlessly unscrewed by hand.

After intensive work with metal tools, you may find a buildup of burnt and abrasive scale inside the shroud. Use a steel brush to remove any residue.

After cleaning the bottom flange is installed in place, combining the grooves of the spindle with the grooves of the flange. A spacer is placed on top.

If your model does not have additional spacers, similar washers can be prepared from plastic or heavy cardboard. Next, you need to properly put the disk on the angle grinder and cover with a similar gasket.

Important! The spacers installed make it easy to unscrew the nut even if the disc is jammed or broken.

With your hand you twist the upper lock counterclockwise (counterclockwise), supporting the cutting wheel. In doing so, you must also clamp the spindle lock and tighten the flange until you feel resistance. Using the horn wrench pull with a little more force. You should not overtighten the mount, otherwise you can overtighten the wheel and it will warp.

Now you can continue to work. However, problems occasionally arise, and to unscrew the disc on the angle grinder is not easy. How to change the disk on the angle grinder in such cases, let’s look below.

Types of discs for angle grinder

angle grinder is widely used in construction and repair technological operations. Discs for 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 discs for the angle grinder, are also called abrasive. They are classified in different ways. discs are available for working with metal, stone, wood. There is also a diamond disc, which serves to work with the most durable and hard materials (reinforced concrete, porcelain tiles, tiles, marble, granite and other natural and artificial stones).

Let’s give a brief description of each type.

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

  • 115 mm for small domestic power drills;
  • 125 and 150 mm for medium power and weight angle grinder;
  • 180 and 230 mm for powerful professional tools.

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

Cutting (abrasive) circles for metal

These discs are used to work with sheet steel (disc thickness from 1 to 1.6 mm) and long steel products: rebar, round bar, channel, angle, and others (disc thickness from 2.5 to 3.6 mm). There are special heads for working with stainless steel, aluminum, cast iron and other metals.

This is indicated on the surface of the disc by markings and a colored stripe. Abrasive discs consist of 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 obtain strength. Set temperature of heating. 200 degrees. There, the mass is sintered and becomes hard and resistant to shattering.

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Abrasive discs for stone

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

For wood

They are made of high-strength steel and are equipped with sharp teeth on the outside diameter. These attachments work on the principle of the circular saw and are quite dangerous in operation. It is recommended that the angle grinder permanently fixed with a special device.


They are used for cutting high-strength materials of natural and artificial stone.

There are different kinds of diamond discs for concrete, reinforced concrete, stone. They differ from each other by the fractionality of the diamond coating and the type of cutting edge. solid, with large or small cuts, notches. it is important to know that diamond wheel is not used for metal work. It is difficult to understand the purpose of diamond discs by their appearance. The best solution is to consult the sales consultant or carefully study the package addendum before buying.

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

  • The green one is for granite;
  • Yellow. for plaster and tile;
  • blue. for marble and concrete;
  • Grey. for granite and tile;
  • orange. for bricks.

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

Grinding and roughing discs

Grinding discs are divided into four types:

    Petal-type (abrasive) wheels remove old paint, primer or varnish, sand woodwork.

  • Special wire discs remove rust and persistent dirt.
  • Stone is polished with diamond bowl modifications.
  • Discs of plastic or rubber are used to polish metal surfaces. Replaceable discs with sandpaper, felt, sponge, cloth can be mounted on the discs.

Most sanding discs work with special pastes or fluids that include the finest abrasives. These attachments are used to grind surfaces of any material, including car body parts in car repair shops.


If you had to use a gas wrench, you should remember about the very strong shoulder of such a wrench and the amount of force applied to the parts of the angle grinder. If you are not careful, you could tear 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.

Work with “angle grinder” involves a lot of waste in the form of metal or wood shavings and dust. Before you begin, you must wear special protective goggles: they will protect your eyes from the splinters of the cutting wheel in the event of its jamming and destruction.

Glasses are necessary not only as a safety element. If the eyes are protected, you can pay more attention directly to the work of the “angle grinder”, to ensure the correct cut or select the correct mode of operation. It allows to use consumable materials (cutting-off wheels) in the most effective way and minimizes occurrence of emergency situations with disk jamming or its destruction.

It is especially important for craftsmen with poor eyesight who wear dioptric glasses, on which they cannot wear safety glasses, to replace safety glasses perfectly.

The disc on the “angle grinder” can be installed both “on itself” and “on itself” depending on the direction of rotation and, accordingly, the flow of chips. There is no fundamental difference in operation. However, the “angle grinder” with the disc “on itself” tends to bounce forward out of the cut if the disc jams, and not at 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 specially mounted extension cord with a socket, preferably without grounding, will help to quickly stop the work of the machine that has escaped from the hands.

“Angle grinder”. a tool of rough treatment and do not strive to get a perfect surface as a result of its work, the main thing is to make a rough cut, which later, if necessary, can be processed by other methods.

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To work without clamping and jamming long metal workpieces is better not to cut all the way through, leaving 1-2 mm of metal in the cut: they will be easy to break off afterwards, it will have almost no impact on the quality of the workpiece.

It is better to place small workpieces in a vice or clamp them to the workbench or other reliable horizontal surface. On the tightness of the clamping depends and the quality of the cut and safety.

Fixing washer, as a rule, comes with special grooves, and it can be unscrewed only with the appropriate wrench, which is usually included in the set of each angle grinder.

Some angle grinders are equipped with conventional nuts that can be unscrewed with an open-jaw wrench.

To unscrew the fixing washer in its grooves need to install a wrench angle grinder.

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

Then turn the key counterclockwise.

This is how the fastener is unscrewed, then the old disc is replaced with the new one.

After installing a new disc in place, first screw the fixing washer by hand, and then tighten it with a wrench.

Now the angle grinder is “loaded” with a new disc, and you can get to work.

Possibilities, dangers of working with unsuitable discs

There is a temptation to install a larger or smaller wheel. Let’s try to predict the work of an angle grinder and the difficulties we may encounter.

  • It is possible to install a pancake of similar size on the tool with the same spindle speed, considering that it is easy to do and the seating is the same. Instead of a 125 mm wheel, you can install a 115 mm. This is normal. the spindle rotation is the same, the diameters are almost the same.
  • If you try to put a 125 mm wheel instead of a smaller one, you will face a mismatch in height of the protective cover. The gap will remain, but it will be too small. After that, you must either change the cover for a larger size, or stay without it. Rotation speeds are the same, the probability of parasitic vibrations is minimal, but no one canceled the safety rules. There is a chance of breakage, and sparks flying everywhere get in the way. The pancake can get caught in the metal, bend badly if you move it awkwardly. It can break apart due to poor workmanship. You can’t do that!
  • The wheels on grinders with seat size of 150-180 mm can also be swapped. These models have lower speed. up to 8500 rpm. That’s why it’s easy to put a little smaller. But it would be hard to do the opposite, because the guard would get in the way. You only have to remove or replace it with a grinding wheel of a corresponding diameter. About the dangers of working without the hood was said above.
  • Change your large angle grinder‘s grinding wheel to a smaller one. Theoretically it is realistic, but the weight and size of the tool will prevent accurate work. The size of the disc beyond the diameter of the spindle is also small. Small pancakes have a thickness of 2-3 times less, so the inconvenience of working threatens to break the wheel. A high deflector guard would not be effective against debris.

It happens that on a small machine is required to install a wheel of large size. The nuances of this manipulation:

  • The guard will interfere and will have to change to a larger one or work without it;
  • at speeds of 11000 per minute, heavy loads are contraindicated. you can only neatly cut thin metal;
  • The size of the pancake is comparable to the size of the tool, which will make it difficult to work in fast cuts of thick metal and threaten to pull the machine out of his hands when jamming the disc;
  • Having a turnover adjustment, they can be reduced to 8000, but the problem of small lever and the weight of the tool will not go anywhere, and this threatens injury.

Mind you, it is important to work responsibly and safely. That is why you should not put large-sized discs on small machines. they will not withstand the load. It is required to use only discs for specified rotation parameters.

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