Last updated: 17/10/2022

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Welcome to our big concrete grinder test 2022. Here we present all the concrete grinders we have tested in detail. We have compiled detailed background information and added a summary of customer reviews on the web.

We would like to make your purchase decision easier and help you find the best concrete grinder for you.

You will also find answers to frequently asked questions in our guide. If available, we also offer interesting test videos. Furthermore, you will also find some important information on this page that you should definitely pay attention to if you want to buy a concrete grinder.




Summary

  • A concrete grinder is the right choice for you if you are looking for a grinder to grind down hard to very hard materials.
  • The concrete grinder shows its strength especially through high reliability and durability and all in all suitable costs.
  • There are inexpensive concrete grinders available. For top grinders you usually have to calculate more money.

The Best Concrete Grinder: Our Picks

Guide: Questions you should ask yourself before buying a concrete grinder

When do you use a concrete grinder?

Concrete grinders are mainly used in renovation and restoration for grinding concrete, plaster, screed or natural stone.

They are then primarily used for removing old coatings, old layers of paint, carpet or tile adhesive and for smoothing substrates afterwards.

The concrete grinder is a hand tool used for grinding mineral substrates. Concrete grinders use round grinding wheels mounted on the drive axle that rotate at speeds up to 10,000/min.

What are the different types of concrete grinders?

Concrete grinders are available in different designs, each with certain advantages or disadvantages. Here is a brief overview of the most common types:

Floor grinders are machines that are equipped with an integrated chassis and can be used from a comfortable working position: The grinder is guided comfortably from a standing position over the surface to be worked on.

A height-adjustable handle ensures that the working height can be adjusted individually. Thanks to a usually much larger sanding disc with a typical diameter of 235 mm, such a machine is perfectly suited for working on larger surfaces.

Diamond grinders are specially designed for use with monobloc diamonds. This allows different materials such as concrete, screed, natural stone, adhesive residues and coatings to be milled off with one disc.

Particularly with abrasive materials, up to 3 times higher grinding performance and up to 10 times longer service life is achieved compared to conventional diamond grinding discs. The typical disc diameter here is also 125 mm. The weight is more than 5 kg.

Angle grinders are classic machines with an angle grinder shape that are driven by an angle gear. They can be operated like angle grinders. The disc diameter is typically 125 mm, which results in a compact design overall.

Concrete grinders are available in various sizes and designs, including one similar to the angle grinder. These relatively small devices can also be used to work in places that are more difficult to access. (Image source: pixabay.com /skeeze)

This gives them a significant advantage in that sanding is possible even in tight places. In addition, they have a relatively low weight of about 3 kg in most cases. However, with this design, good shielding of the motor is necessary, as penetrating dust could impair the machine’s service life.

Tower concrete grinders are concrete grinders with a tower shape in which the motor is positioned vertically above the grinding plate. The handles are located to the right and left of the motor. This handle position makes for comfortable, ergonomic operation.

In addition, the handles are often vibration-damped. The typical disc diameter is also 125 millimetres. However, the weight is often more than five kilograms.

The functionality of the device changes depending on the type of sanding disc and the height of the handle. Depending on the type of grinding disc, the concrete grinder grinding disc has different longevity.

What happens to the dust?

The machines typically work with rotating sanding discs that are guided over the surface to be worked on so that material is removed from the surface.

Due to the high dust generation during sanding – which can be very harmful to health in the case of mineral materials – a good machine should therefore have an effective dust extraction system. As a rule, the machines are also equipped with a so-called brush ring, which ensures that less sanding dust can escape sideways.

Did you know that the sander needs to be cleaned regularly to ensure a long service life?

Due to the heavy dust build-up, a grey haze tends to settle on the machine housing. When the machine is switched off and disconnected from the mains, you can wipe off the dust with a damp cloth. A brush often helps in hard-to-reach places

Decision: What types of concrete grinders are there and which is the right one for you?

Basically, you can distinguish between four types of concrete grinders:

  • Concrete grinder
  • Diamond grinder
  • Angle grinder
  • Tower grinder

A concrete grinder is mainly suitable for dust-free removal of formwork and concrete residues and for smoothing floors and walls. The removal of the top layer creates a well-finished and smooth surface that is ready for further processing.

A concrete grinder is usually a hand-held power tool suitable for removing concrete, screed, plaster and coatings. In many cases, however, they are also used for cleaning substrates in preparation for coating or applying top coats or coats of paint.

Most models are designed to be used together with an industrial vacuum cleaner to extract sanding dust. However, modern devices already have a partially removable extraction bonnet. Choosing a concrete grinder with speed control opens up further possibilities for use.

When buying, you should pay particular attention to the motor power of your preferred device. When using the grinder, be sure to use the correct grinding disc, otherwise serious damage to the floor may occur. Before buying, you should compare the different types of concrete grinders with your intended use.

The following section briefly explains the differences between the various types so that you can decide for yourself which concrete grinder is right for you. The advantages and disadvantages of each grinder are also described.

How does a concrete grinder work and what are its advantages and disadvantages?

The classic concrete grinder allows a thorough and extremely powerful treatment of various surfaces. This type is hand-operated and is mainly equipped with an electric drive. However, there are also models that are powered by a petrol engine.

Especially when renovation or restoration work is taking place, it often happens that concrete floors, plaster, screed or natural stone surfaces need to be polished up. With a concrete grinder, old paint residues, adhesive residues or old coatings can be easily removed and also smoothed.

The grinders work with a rotating grinding wheel or a grinding plate. This is guided over the surface to be worked on and thus removes the material from the surface.

It is essential that respiratory protection is worn during the work. This is necessary because dust can be harmful to health, especially when sanding mineral materials. Most concrete grinders therefore already have a connection for an extraction machine.

Most grinders are equipped with a brush ring that prevents the grinding dust from escaping sideways. From a standing position, the unit can be guided over the surface and enables large areas to be sanded quickly. With this sander, the material is removed in chips by rotating the sanding disc.

Advantages
  • Fast and thorough
  • Pleasant to use
  • Versatile range of applications
Disadvantages
  • Requires electricity
  • High noise level
  • High vibration power
  • High dust formation

How does a diamond cutter work and what are its advantages and disadvantages?

The diamond grinder is suitable for so-called concrete cosmetics of all kinds of concrete surfaces. The diamond tools consist of high-quality, hardened and ground steel beam elements. When using them, there is a big difference whether the surface to be used is dry or wet and what the temperature is.

As a rule, diamond segments are very heat resistant. The segments are made of metal powder and diamond crystals pressed together under high pressure to form different segment shapes. The diamond crystals chip or grind the material.

With optimally selected diamond segments, the matrix is worn down just enough so that enough diamond crystals are always ground free, which can then participate in the cutting process. Premature breaking out of diamond crystals increases the chance of higher wear.

When working on abrasive materials such as screed, fresh concrete or asphalt, larger pieces are torn out than with concrete, for example. The bond must be hard and homogeneous here, otherwise the binder is removed too quickly. Segments for hard and dense materials require a softer bond for optimal free grinding of the crystals.

The consequence of this is that a concrete blade can be used for cutting screed, for example, but in return increased wear must be accepted. Viewed differently, the diamond segments become blunt when machining abrasive materials, as not enough diamond crystals are exposed.

With this type of grinder, it is essential to pay attention to the ratio of binder to diamond content and the size or shape of the diamond crystals. In all cases, a high-quality device should be purchased, as the application and thus the success of your work also depend on the quality.

Advantages
  • Highly aggressive
  • Little effort required
  • Almost dust-free
  • Enables precise work
Disadvantages
  • Comparatively expensive
  • Strong differences in quality

How does an angle cutter work and what are its advantages and disadvantages?

In this type of concrete grinder, the electric motor is parallel to the surface being cut. This is specially built for angles. The drive torque of the angle grinder is diverted via a gearbox. When choosing an angle grinder, the power plays a particularly important role. It should be between 1,000 and 2,000 watts.

However, a distinction must be made between power consumption and power output. The power output indicates the actual strength of the tool. In a good-quality appliance, both values are close to each other. In addition, attention should be paid to low vibration. In other words, the unit should be quiet and smooth when idling.

The idling speed provides information about the speed of the motor. The disc size is also of great importance, as the speed of the discs also depends on the choice of diameter. In addition, a model with ventilation slots in the housing should be chosen, as these protect against overheating and ensure a longer service life.

They are responsible for ensuring that metal and wood splinters, sparks or dust are removed immediately via the ventilation slots. A two-hand angle grinder is best suited for sanding various surfaces. The motor promises high performance and a large amount of power. In this way, it is possible with a two-hand flex to cut through even hard materials such as stone, steel and concrete.

Working with this flex for a long period of time requires a lot of power and effort. There is only one speed, which speaks for a linear speed and consequently for a clean cut, but can also be very strenuous for the body.

Therefore, when using a two-hand angle grinder, it is important to make sure that the model has a soft start. Otherwise you run the risk of drawing too much current when starting.

The soft start also means that the flex does not tear too much when starting. When working with a large and heavy flex, safety goggles, protective gloves, safety shoes, ear protection and flame-resistant clothing must be worn because of the strong sparks that are produced.

Advantages
  • Suitable for fine work
  • Light and manoeuvrable
  • Space-saving
  • Versatile use
Disadvantages
  • Requires a lot of power
  • Unsuitable for delicate work

How does a tower grinder work and what are its advantages and disadvantages?

In a tower-shaped concrete grinder, the motor is positioned vertically above the grinding plate. The handles are to the right and left of the motor. This handle position offers comfortable and ergonomic operation. Another big advantage is that the handles are in most cases vibration damped.

The average disc diameter is around 125 millimetres and the weight is usually over five kilograms. This type of concrete grinder is one of the most frequently used for interior work, as it is particularly suitable for grinding floors and all materials.

Advantages
  • Easy to operate
  • Comfortable grip position
  • Vibration-damped handles
Disadvantages
  • No quick results
  • Device takes up a lot of space

Buying criteria: You can use these factors to compare and evaluate concrete grinders

In the following, we would like to show you which factors you can use to compare and evaluate concrete grinders. This will make it easier for you to decide whether a certain product is suitable for you or not.

In summary, these are:

  • Stability
  • Weight
  • Power
  • Speed regulation

In the following paragraphs you can read about the individual purchase criteria and how you can classify them.

Stability

Concrete grinders are electrical devices that are exposed to considerable stress during operation. Therefore, an important purchase criterion for a plaster grinder is the quality and load capacity of the device. All parts that conduct electricity must be safely installed and protected.

Some machines can be converted into an angle cutter or a renovation router by replacing the grinding plate. In this way, other materials such as wood or metal can be processed with the same machine. (Image source: pixabay.com / skeeze)

The same applies to the electronics. The housing must be very sturdily constructed and sealed, as vibrations are constantly generated during sanding and put a strain on the housing.

Weight

Of course, the weight of the renovation router is important and should be one of the purchase criteria to maintain both comfort of use and protection against accidents.

This applies to hand-held models, of course. Models for the floor are consequently heavier. Models with better or more features are also inevitably heavier.The weight of the grinder varies from 2.6 to 75 kilograms, depending on the function and accessories.

Power

The most important criterion is the performance of a concrete grinder. High-quality devices usually have a considerably higher output and thus also enable better and faster work than cheap models.

In the professional field, and when lengthy work has to be done on different substrates, a powerful concrete grinder is necessary that also has enough accessories to be adaptable to different requirements.

The power of the grinder varies from 700 to 3200 watts.

Did you know that it is difficult to operate a concrete grinder?

To ensure safe guidance, it is important to guide the grinder over the concrete with force. A grinder like this is very heavy, so you have to have the necessary strength here.

Speed control

A good concrete grinder and cut-off machine should be able to vary its speed. The speed of the grinder used to work the surface plays a role in achieving the desired work result.

Some renovation grinders, such as the angle grinder, have an electronic speed control that allows you to regulate the rotational speed from 3000 – 12000 rpm in seven steps. The digital display always lets you know immediately how many revolutions per minute you have set.

The speed of the grinder varies from 1000 rpm to 22000 rpm.

When buying, you should pay attention to the maintenance costs of the machine. Concrete grinders with different drive types have the incidental costs like petrol and cleaning of the grinding plate.

Photo source: 123rf.com / kzenon

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