Why you can't grind with a grinder cutting disc

Why you can't grind with a grinder cutting disc Cutting disc for grinder : description, features and why they should not be sanded

Angle grinder, or as it is also called, "grinder", is one of the varieties of grinders that are used for grinding and cutting metal, concrete, stone, and other materials used in construction.

The material principle of operation is based on the fact that materials rub against each other at high speeds. The required effect is achieved due to heating of the surface of the processed object at the point of contact to a high temperature, and this leads to controlled mechanical damage - polishing, cutting or cleaning.

Replaceable grinding or cutting elements of such an electric tool are special wheels. The most common of them are cutting discs for grinders for metal and wood.

What is it

Cutting discs for an angle grinder are hard discs that are dark gray in color, slightly rough to the touch, have a mounting hole in the center, and they are also framed by a steel ring, which is galvanized. They differ in size, material of manufacture, configuration and other characteristics that determine the type of work that needs to be done with an angle grinder.

In construction practice, circles for metal are very often used. The cutting effect is created by high-strength artificial materials that have been crushed into chips. Also used are electro-ores - refractory, very hard, chemically resistant compounds, which are based on aluminum oxide.

In accordance with the direct purpose of the disc, electro-runds can be applied on the following bases:

  • Chromotitanic.
  • Magnesium-silicon.
  • Titanic.
  • Zirconium.
  • Alumina.

  • Chrome.

Cutting discs for an angle grinder for metal are nothing more than a consumable that is not supplied by the manufacturers with the tool. The manufacturer of the electric grinder is not responsible for the quality and wear resistance of consumables.

Please note that the cut-off type consumables for the angle grinder have an increased wear rate because they are subject to high mechanical stress in the form of heat and friction. At the time of use, a lot of sparks are produced (they are always orange).

These are nothing more than red-hot particles of the disc and the material that you are processing. During wear, the circle will become smaller in diameter, and this reduces its efficiency (efficiency).

Types and sizes

Why you can't grind with a grinder cutting disc Cut-off wheels have a smaller profile section - thickness than that of grinding.During the working process, the end part is used, which, in contact with the metal, literally frays it. This type of disc has two types of configuration, which differ in thickness, namely 0.

15 and 0.2 cm.

The central mounting hole is the same for all types of discs - it will correspond to the diameter of the attachment shaft of the angle grinder. On the continent of Eurasia there is a single standard of this magnitude. All angle grinders for general use have the same diameter of the attachment shaft, on which a replaceable disc (disc, attachment) is put on.

Interestingly, that the main differences between the cutting wheels will be reduced to the difference in the outer diameter, and this parameter makes it possible to use discs for angle grinders of different power and size.

The uniform standard sizes of diameter are as follows - 11. 5 cm, 12. 5 cm, 15 and 23 cm. The best cutting discs for a grinder are always made according to all standards.

By the way, there are specialized circles that are intended for products that are made of "problem" metal - viscous, soft and high-carbon. To distinguish them from other varieties, manufacturers use special marking codes.

With the help of such designations, you can determine which circle is better to use in a given situation:

  • For work with steel, use steel wheels.
  • To cut stainless steel, you need inox.
  • For cutting cast iron products, the castiron is the best option.

  • Cutting soft metal is always best done with an aluminum wheel.

Next, we propose to consider how to choose the right circles.

Recommendations for the selection of a circle

First, be sure to pay attention to the diameter of the circle. It must necessarily correspond to the dimensions of the protective casing from the angle grinder and be placed in it so that it can rotate freely. As a rule, its diameter is written on the face of the disc.

It will be enough to compare such an indicator with the permissible value, which is given in the passport of the angle grinder. In order to choose a cutting wheel for metal, you need to take into account the fact for what kind of work you plan to use it, on which specific electrical tool, and also under what circumstances.

When sawing metal with a thick profile, be sure to use a thick cut-off wheel. The fact is that this makes it possible to reduce the wear process and reduce the risk of destruction. During the operational process, the cutting element will be heated to a high temperature, and the thicker the metal, the higher the degree of heating.

When the permissible temperature threshold is exceeded, abrasive particles begin to detach from the bulk more intensively, which is why the circle collapses very quickly.

Thin profile metal starts to "scratch" the disc during sawing, which accelerates the wear process. For this reason, a circle with a thinner profile is perfect for such work, because it has a smaller area of ​​contact at the point of friction. An important criterion when choosing a cutting disc for metal cutting will be the production brand and price category. Domestic manufacturers usually supply not very expensive materials, but they have low quality characteristics.

Such circles are not durable, and still very unsafe to use. Suppliers from overseas offer a higher quality option at higher prices.

Pay attention, that you should also take into account the price-quality ratio with the characteristics of the work being carried out. If you plan to use a removable disk one-time and for a short time, then it will be much more profitable to buy an inexpensive nozzle, but if you need long-term work on cutting metal and have high demands on the quality of the saw cut, then the inexpensive option must be excluded.

Correct use

Preparatory step

The use of the angle grinder cut-off wheel begins from the fact that it is required to follow the rules of installation and removal.


Be sure to check the position of the lower control nut on which the disc will rest. Its spline must necessarily coincide with the spline of the angle grinder shaft. Next, we put the circle on the shaft, and the side that contains the marking data must be visible.

After screwing on the control nut, and holding it with your hand, you should try to turn the disk in the direction of travel. In the process of cutting metal, the difference in the directions of rotation of the nut and disc will create a self-tightening effect.

When installing, do not tighten the upper nut with a wrench.


Wait until rotation stops completely. Next, disconnect the angle grinder from the mains, insert the “horns” of the special key into the holes of the upper control nut and squeeze the lock button. Rotate the wrench counterclockwise and when the nut is pulled out of place by the initial force, it can be unscrewed by hand. Any angle grinder must be equipped with a handle connector, and it is forbidden to work with the handle removed.


A cutting disc for a grinder for wood will serve you for a long time and correctly if you follow special rules. Before starting work, you should think about how the cutting will be performed (the position of the angle grinder in space in relation to the cutting site), determine the direction vector of the flow of sparks, which will accompany the immersion of the disc into the metal.

Next, remove all objects and liquids that are highly flammable, and they should be as far away from the spark flow line as possible. If necessary, cover the finishing surfaces that will be exposed to sparks with special protective equipment.

Also, do not forget to inspect the electrical tool itself for sand, water, dirt, and also check the integrity of the electrical power cord.

A test run should be carried out in order to check the operation of the unit for uninterrupted and unimpeded rotation of the cutting disc. Evaluate the material of the cut - it must be firmly fixed, not have deforming stress, and also be as far as possible from electrical wires.

Please note that it is strictly forbidden to start work with an angle grinder unless you intend to observe safety measures and use personal protective equipment.

Eyes must be protected by special glasses that give a clear and wide view. It is best not to use glasses that have tinted lenses.

The safest way to protect your face is to use a face shield, which is made of transparent organic glass.

Why you can't grind with a grinder cutting disc In the case when the disc is destroyed during cutting, its fragments begin to fly away in the direction of the initial centrifugal force with incredible speed.

This mask is able to protect the front of the head from hitting them. The hearing organs also need protection, and for this, the best solution would be to purchase and further use silicone earplugs or construction headphones.

The angle grinder operator should have special equipment that will meet the following safety measures:

  • Rob should be made of natural and durable material.

  • Clothes should be loose enough, but sleeves that are too long are not allowed.
  • Gloves should fit snugly around the hands, be made of sturdy material and be able to contain the initial cut.
  • Closed-toe shoes must be fitted with composite toe inserts.

Next, consider the performance of work.

Work progress

When turning on the angle grinder, hold the angle grinder with enough force to overcome the starting torque.

The angle grinder, which is released from the hands at start-up, can seriously harm the operator and damage the material. Keep a working angle grinder upright and avoid sharp body rotation. It is worthwhile to bring the rotating disc to the metal element slowly, immerse it without effort, so that the unit's own weight creates the desired coefficient of friction.

When the cutting wheel for the grinder is immersed in the material by 1/10 or 1/5 part, then you should pay attention to how smooth the cut is. If the device begins to twitch or pulls forward strongly, then it may be necessary to change the angle of inclination of the body or reduce the pressure of the disc on the metal.

If the metal workpiece has a lot of stress, then cut to 90% and finish the process by hand.

Why you can't grind with a cutting disc

Although many home craftsmen claim that you can adapt almost any disc / attachment for many other purposes (besides the main one), it is better not to do this ... If a cut-off wheel is used for grinding, core tearing may occur.

It is precisely about the complete tearing out of the metal ring in the center of the disc.

This is a rather dangerous case, which is associated precisely with improper operation. This can happen every time a strong lateral load is applied to the disc (turning or tilting the tool sideways), as well as the use of a cutting disc for grinding. To avoid this, use only grinding discs, and do not forget to use original (i.e.

factory) flanges of the same diameter. Otherwise, terrible things can happen and you will need the help of a surgeon.