Choosing And Replacing Disks For An Angle Grinder

Angle grinder (angle grinder), in common people called “angle grinder”, is widely used in construction and in everyday life during repair. With its help, you can perform many different technological processes. To choose the right tool to perform a certain type of work, you need to familiarize yourself with what kind of discs and nozzles are for an angle grinder. The tool for this device is selected by size and purpose.

Typical Drive Sizes

When choosing a disk for an angle grinder, make sure that the outer diameter of the nozzle does not exceed the maximum allowable values ​​allowed for your angle grinder. For example, if an angle grinder is designed to use a wheel with a maximum diameter of 125 mm, then a 230 mm wheel cannot be installed on it. And there are several explanations for this:

  • the linear speed of the cutting edge will be exceeded, which is fraught with the destruction of the abrasive wheel and causing injury to the user;
  • a small angle grinder does not have enough power to work with a large tool;
  • installation of a nozzle exceeding the permissible dimensions requires removal of the protective cover, and this is already a violation of safety rules.

Discs for angle grinder have standard sizes: 115, 125, 150, 180 and 230 mm. In modern angle grinders landing diameter (the diameter of the shaft on which the tool is mounted) is almost the same and equals 22.2 mm. If you have an “outdated” angle grinder of an outdated model, then you will need to use adapters. rings of different diameters.

All abrasive wheels of any size have special marking, from which you can find out the following information: the diameter of the disk and its thickness, the diameter of the seat, the maximum rotation speed, and also for the processing of what materials it is intended.

Choosing And Replacing Disks For An Angle Grinder

Purpose of disks and nozzles

Circles for an angle grinder differ in purpose to:

Cutting discs

The most common task performed with an angle grinder is cutting various materials. The choice of tool material depends on what material will need to be cut.

  1. Metal cutting. A cutting disc for metal is made from crystalline alumina corundum, as well as from synthetic corundum called electrocorundum. The main color of metal cutting wheels is blue.
  2. Cutting stone and concrete. For cutting stone, you should choose a disk from another abrasive material. silicon carbide. This abrasive easily cuts white brick (silicate) and slate. But in order to cut red brick, some types of concrete or ceramic tiles, this circle material will not work. Disks for a stone are issued green color.
  3. Cutting ceramic tiles, red bricks, porcelain tiles and concrete. A diamond disk is already being used for these purposes. This nozzle is made of metal, an abrasive mass with diamond chips is applied to the cutting edge. The figure above shows a segmented saw blade designed for dry cutting of material. All-metal disks require water cooling during operation.
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  • Wood cutting. Although there are wood sawing wheels on the market that are no different from compass saw blades, it is best to abandon their use for safety reasons. When working with such a tool, the user often suffers severe injuries due to jamming, bouncing, accidental slipping of the tool, etc.
  • Therefore, if you are still going to use a saw blade on a tree, you should adhere to security measures. A protective cover and a handle must be installed on the angle grinder, the user must wear a protective mask or glasses. In addition, you cannot cut materials that are not intended for it with this tool.

    The most safe are disks on wood, at the end of which a chain from a chainsaw is installed. In case of jamming of the tool, the chain remains in place, and the disk rotates idle, which reduces the likelihood of injury to the user.


    If you want to remove a layer of paint or other application, as well as rust from any surface, apply wrinkles. They are disk or in the form of a bowl with a built-in metal wire.

    The wire in these nozzles can be twisted or loose. Its thickness can also be different. The thicker the wire, the rougher the roughening is used peeling disk or cup-shaped nozzle, and vice versa.


    For grinding and polishing various surfaces (metal, wood, plastic and others), grinding discs and nozzles are used. A grinding wheel is often used for grinding. petal type. It consists of many “petals” made of sandpaper. The grit of sandpaper can be selected based on the desired type of processing (finishing or roughing).,

    Video: Choosing And Replacing Disks For An Angle Grinder

    Also, sandpaper can be attached to the nozzle using Velcro. Such a tool is screwed onto the spindle by an angle grinder.

    Special circles and nozzles are produced for polishing surfaces, looking like pillows made of felt or like disks made of fabric.


    To sharpen the tool, grinding machines (sharpeners) are usually used. But if you don’t have the latter, but there is an angle grinder, then you can buy a grinding wheel for it, which can be used to sharpen almost any cutting tool.

    The main difference between grinding wheels from cutting wheels is their thickness (at least 5 mm).

    How to change a disk for an angle grinder

    Since the wheels for the angle grinder are consumables, sooner or later they have to be changed. They are mounted on the spindle by an angle grinder with a clamping flange (nut) with M14 thread. To unscrew it, in the configuration for the angle grinder there should be a special open-end wrench, having pins on one side.

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    So, to replace the tool with an angle grinder, follow these steps.

    1. Disconnect the device by unplugging the plug from the outlet.
    2. Lock the spindle angle grinder with the button located on the front of the housing. When the button is pressed, the stopper enters the hole of the disk installed in the gearbox, which fixes the spindle in a fixed position.
    3. Insert the key pins into the holes on the pressure flange.
    4. While holding the lock with one hand, use the other hand to turn the key to the left (counterclockwise) until the nut comes loose. Then it can be unscrewed without a key and removed from the shaft. In this case, the spindle angle grinder rotates clockwise. But in which direction to unscrew the nut, if your device rotates the shaft counterclockwise? Remember: the clamping flange should always be unscrewed in the opposite direction to the shaft rotation.
    5. Now you can change the tool by first removing the old one. If you notice that dirt has accumulated inside the casing, remove the bottom flange and remove dirt from all surfaces with a steel brush.
  • Screw the flange onto the shaft by hand. The nut should be tightened until you can no longer turn it without a key. After that, holding the stopper, tighten this nut with the wrench, but no more than a quarter of a turn, otherwise the disk will begin to deform.
  • After carrying out the above steps, replacing the tool is considered to be completed.

    Methods of unwinding if the disc is jammed

    What to do if the pressure flange is jammed? This nuisance, when bitten by a nut, often occurs if the tool is stuck in the workpiece when working with thick and strong materials. At the same time, the abrasive wheel often breaks, and the spindle that continues to rotate tightly tightens the clamping flange. To unwind the angle grinder, if the disk is clamped, there are several ways.

    With a gas key

    This method is considered not quite safe, since it is possible to break the stopper, although in most cases, it is possible to unscrew the nut. In order not to break the spindle lock, do not apply excessive force to the gas wrench. The design of the lock is designed for the force exerted by the standard key.

    Unscrew the excessively clamped flange using 2 gas keys. To do this, break off the sticking ends of the abrasive wheel with pliers so that you can get the first gas key to the lower flange. Next, hold both flanges with the wrenches and turn them in opposite directions (taking into account which thread on the spindle is right or left).

    Gearbox disassembly

    In case the lock is broken, to remove the tool from the angle grinder, you will have to disassemble the gearbox. Break off the edges of the remaining abrasive wheel with pliers so that you can get to the bolts holding the gearbox cover. After that, unscrew the fasteners and open the gearbox. The cover is removed with the pinion shaft. Further, this shaft should be clamped in a vice, having previously laid aluminum gaskets between the steel jaws, and using a gas key to unscrew the flange (do not forget to determine the direction of unscrewing).

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    Nut heating

    The nut can be heated with a gas burner, building hair dryer or blowtorch. The heated flange is usually obtained by unscrewing with a standard key for an angle grinder.

    Stitched circle sewing

    If after applying the first 3 methods the nut does not loosen, then the remaining abrasive wheel between the flanges can be ground. To do this, do the following.

    1. Use a pair of pliers to remove the rest of the circle along the edges of the nut.
    2. Grip a piece of sheet iron in a vice that is as thick as the disc itself, turn on the angle grinder and grind the rest of the circle onto the end of the sheet iron.

    Instead of iron, a piece of abrasive wheel can be clamped in a vice. In this case, the grinding of the rest of the tool between the flanges will be faster, and the nut can be unscrewed by hand.

    But the use of a stationary abrasive wheel requires great accuracy, because when grinding the remains of the tool, the geometry of the flange can be damaged. If this happens, you will have to cut the nut.

    Using penetration grease

    Water the joint between the flange and the shaft. liquid WD-40. It has the property of penetrating into inter-threaded spaces and small gaps. After applying the fluid, wait about 5 minutes and try unscrewing the fasteners with a standard wrench.

    Using a hammer drill

    Some owners of grinders in a situation when the clamping nut is jammed, install a nozzle in the punch “chisel "or" jackhammer”, Insert it into the hole of the flange at an angle and turn on the jackhammer without rotation. Accordingly, the stopper button must be pressed. All that is needed is a couple of gentle presses with a puncher (so as not to break the shaft lock), and the nut will begin to turn.

    Cut the pressure flange with a hacksaw

    This method can be called radical, because you have to buy new fasteners, and it is used if the nut is not unscrewed by any other methods. To saw the flange, hold down the stop button so that the shaft does not rotate and, applying hacksaw, cut the fixing nut.