Rotary hammer for working with a concrete crown

How does the work of a puncher begin?

Punch adapters and extensions have different characteristics: power, length, etc.

After installing the necessary attachment on the tool, you can start directly to work. After connecting the punch to the power supply, you must make sure that the mode switch is in the desired position. Then you need to let the tool run for at least a minute without load, at idle speed.

It is important that there are no extraneous sounds during the operation of the gearbox. Smoke and burning odors can also indicate a malfunctioning instrument. If no signs of malfunctions are noticed, you can start work in the selected mode.

When the hammer drilling mode is selected (this mode is sometimes called drilling), the toggle switch is switched to the position where the drill and hammer symbols are shown above the mark. Then the drill is located in the place where the future hole is marked, and only after that the tool is turned on.

The drill should not be skewed during operation. There is no need to put too much pressure on the hammer drill, but it should be held firmly in your hands. The hole fills with dust and crumbs during operation, so it should be cleaned periodically. For this purpose, the drill should be removed while the tool is idling. After cleaning the hole, further work will require less effort. The position of the tool cannot be changed during operation.

When working in the shock mode, used when removing an old layer of plaster, ceramic tiles, chipping, the toggle switch should be installed above the mark depicting a hammer. The tool should be firmly held with both hands, and some effort will be required during operation. There is no point in leaning too much on the pens. the work will not go faster.

Punch Controls Capabilities

The perforator is selected depending on the scope of work.

Before using the tool, you should thoroughly understand the functions of the controls. Their location in different models may be different. Therefore, it is worth choosing the option in which they are placed most conveniently, and their purpose is the same for each model.

• The trigger is not only for turning the instrument on and off. With its help, the speed of revolutions is regulated, depending on the force of pressing the start button.
• The reverse switch sets the direction of rotation of the chuck. When drilling, the switch position must correspond to the clockwise direction.
• Mode switch. with its help the required operating mode is switched on. Fixes three positions. drilling, chiselling and hammer drilling.

How to use a hammer drill correctly, how long you can, at what time. with a chisel, depth gauge, concrete bit

The hammer drill is able to quickly and efficiently drill holes in any materials.

The hammer drill can replace conventional and impact drills, as well as a jackhammer.

For the correct choice of this versatile tool, everyone who decides to purchase it should know how to use a hammer drill, for what work it can be used, how different models of hammer drills differ from each other. It is especially important to determine what kind of work will be done with the hammer drill.

A high-quality hammer drill, which has a large number of operating modes, is much more convenient to use, and the cost of one, even the most sophisticated tool, will always be less than several, whose functions it can perform.

Restoration drill hammer

Although there are many types of rock drills on the market, differing in weight, size and power, they do virtually the same job. However, if you need to drill a large hole in a concrete wall, then for a hammer drill of low power such work will be overwhelming.

The main parameters for choosing a hammer drill for repair work

For construction work carried out indoors, it is quite enough to purchase a perforator with a power of about 1000 watts. If you need to make a hole in the bearing wall of solid thickness, it is better to use the services of specialists who have a powerful perforator in their arsenal. It is not only unprofitable, but also inconvenient to use a high-power hammer drill when drilling small-diameter holes intended for sockets and switches.

For comfortable work, the main modes of the perforator are required:

• Simple drill. used to drill holes in wood and plasterboard walls. When using the appropriate attachment, the rotary hammer can be used as a construction mixer.
• Impact Drill. Drills holes in concrete walls.
• Jackhammer mode. used when dismantling coatings and chipping channels in walls for laying various types of communications.

Manufacturers usually complete the hammer drill with a special chuck. Its SDS design allows you to securely attach special bits with a thicker shank with notches to the tool. The minimum set includes:

• drills of several diameters designed for holes in concrete walls;
• chisel-bayonet, with the help of which small depressions are hollowed out;
• chisel-blade for channel chiselling;
• a nozzle in the form of a regular chuck, with its help a standard drill and a mixing nozzle are attached.

When buying a rotary hammer, pay attention to the availability of an additional set of brushes.

Bits such as crowns of various diameters are usually purchased separately. With their help, it is more convenient to drill large holes in walls made of various materials. You need to know that for each of the materials, specialized types of drills and crowns are used.

When purchasing a hammer drill, it is better to choose a tool that has a removable support handle. Such a perforator can be conveniently used by people whose working arm is left, since the handle can be fixed in a position convenient for them. Sometimes it may need to be deployed for convenience if it is not easy to get to the place of work.

The safest perforator to work will be a tool in the design of which the manufacturers have provided a safety clutch. Its purpose will be discussed a little later. The power cord must be of sufficient length (5-7 m) so that you can do without an extension cord during operation, and also have high-quality insulation. The layout of the controls should be convenient.

Preparation for work

First of all, the removable support handle is installed in a convenient position for work. Then, having set the tool in a vertical position, you need to insert the necessary attachment into it. For this, the cartridge is pushed down. At the same time, the hole in it increases, making it possible to insert the nozzle.

The nozzle rotates slightly until the nubs on its tail end into the corresponding recesses inside the cartridge. When the goal is reached (setting the nozzle in the correct position), a click is heard. It remains to release the cartridge, after which it is automatically installed in place. The hammer drill is ready for use. All operations for replacing and installing attachments must be carried out with the tool turned off. It must be disconnected from the power supply.

When using nozzles designed for work with a drill, you should install a special adapter-adapter into the perforator, and only then insert a drill, crown or mixing nozzle. When using the adapter-adapter, you cannot use the switch that changes the direction of movement and use the “drilling under impact” mode.

Using the tool in this way can damage the chuck and even detach it from the tool, which could cause injury. In order to avoid danger, a “shock blocking” function is added to the design. It should be turned on when drilling holes in metal, plastic and wood.

Nozzles with thicker shanks must be lubricated with special grease before operation. The lubricant is applied to the nozzle shank. This operation significantly reduces the wear of the chuck and is especially important when the tool is used in percussion mode. The inside of the drill should also be lubricated periodically. There is a special cap on the instrument for this operation. When it is removed, it becomes possible to access the lubrication mechanism, which can be used as a conventional grease.

Features of work when drilling various materials

If holes are drilled in a material that has a porous and loose structure, in order to avoid its destruction, work should be performed in a shock-free mode. If it is necessary to drill a hole in solid material, use liquid cooling. special emulsion, machine oil.

When working with hard materials, it is necessary to take breaks from work. the perforator should cool down periodically. If you need to drill a hole of great depth, it is convenient to use a shorter drill at first, and then continue working with a drill of the same diameter, but longer.

Drilling concrete structures requires special care. Almost always, frames made of iron reinforcement are placed inside them, so there is a possibility of drills falling into it. In this case, the drill can be blocked, and the hammer drill may unexpectedly break out of your hands. To prevent such a situation in modern models of rock drills, the installation of a safety clutch is provided.

The safety clutch prevents the negative consequences of the drill blocking in the valve. However, not all types of perforators are equipped with this device. In the absence of a safety clutch, all measures should be taken to ensure the safety of work. when drilling reinforced concrete, use low rotation speeds of the mechanism and drill without strong pressure. Do not grip the handles of the tool too tightly to release it immediately if necessary.

Basic safety rules when working with a hammer drill

In order to use the puncher correctly, you need to know the basic techniques of working in theory, and practical skills come later, along with experience. However, even craftsmen with solid experience with the tool need to follow basic precautions.

First of all, care should be taken to protect against splinters and crumbs of the processed material. Special glasses will serve as protection against them. Clothing should be long-sleeved and buttoned to prevent it from accidentally snagging on the drill. You can put on a homemade plastic shield on the drill. It will also protect the master from flying particles of material.

Work in places where there are hidden communications requires special attention. If the hidden pipes of the water supply or heating supply are damaged, then this is unpleasant, but not fatal. over, these types of communications are rarely found in a hidden form. Meeting with hidden electrical wiring is much more dangerous.

If the drill gets into a wire connected to a power source during operation, a short circuit, which will result in a de-energizing of the object, will become the easiest outcome of damage. It is not difficult to eliminate it, but an electric shock to a master working with a tool can have the most unpleasant consequences for him.

In order to avoid unpleasant consequences during work, you should have a detailed wiring diagram indicating the locations of its occurrence. If such a circuit is not available, you should use the help of a hidden wiring detector. The cost of the device is low, but it accurately determines the place where the wire is hidden, thereby ensuring the safety of work.

In order for the perforator to serve for a long time, it is necessary to properly care for it. after use, it must be thoroughly cleaned of dust and dirt, not forgetting about the ventilation hole. If necessary, it is allowed to use a soft, damp cloth to clean the instrument.

A cleaned and lubricated appliance will last much longer than the manufacturer’s specifications. It should not be forgotten that only specialists should be engaged in the repair of the instrument.

Crown for concrete: types of crowns and design features

Crown for concrete. accessories for a perforator or drill, with the help of which through technological holes and depressions with a diameter of 30 mm or more are drilled in concrete of various strengths and degrees of reinforcement, as well as in brick and masonry. This device is indispensable for preparing a site for installing sockets and switches, laying communications, communication lines and electrical wiring.

Design features

Concrete differs from all building materials for its high strength characteristics. It contains various fillers, including crushed granite, metal rods and composite reinforcement, which are not easy to drill. The use of a drill or drill in such situations is ineffective. And the use of a special bit for drilling will be a practical solution, since a few minutes are enough to create a hole.

The cutting part of the crown is made of various configurations: a solid edge or with cavities on the sides to remove dust and small particles of construction debris from the drilling zone. The edge or teeth are made of materials whose hardness is an order of magnitude higher than concrete, and for additional strength and durability, diamond or tungsten carbide spraying is applied to the surface.

The set of the crown for the socket can include a replaceable centering drill, which serves to firmly fix the nozzle. It penetrates the wall to a depth of 1.5 m and guides the movement of the cutting edge.

It is convenient to use such a nozzle with a protruding drill. Mounting the drill on the crown simplifies the workflow, allows you to create holes that correspond to the specified parameters as accurately as possible, since vibrations during drilling are excluded.

Varieties of crowns

Crowns for concrete are necessary to create holes in the supporting and enclosing structures of buildings and structures when laying electrical networks, water supply, sewerage and heating, communication lines, fire extinguishing systems, when installing anchors and other types of fasteners.

There are a lot of varieties of equipment for drilling concrete, and they are selected taking into account the tasks facing the master. They differ in size:

• the length of the cutter (from 60 mm), are selected for the thickness of the walls. for thin partitions and blind holes, a length of 15-30 cm is sufficient, a nozzle with a length of 40-45 cm is considered universal, and for thick walls, ceilings and for laying pipes, crowns with a length of 50- 55 cm or more;
• the diameter of the head must correspond to the parameters of the holes, the most popular are the sizes 68 and 74 mm, but nozzles from 4 mm to 1200 mm are available for sale.

The crowns can be mounted on hand drills without impact function and on models with vibration and beating, on rock drills of various powers and on stationary industrial drilling rigs. There are also differences in the principle of attachment to the tool. Flanges are:

Preparing Your Jack Hammer for Use

• three- and hexagonal for use with household drills;
• with SDS Plus shank designed for installation on domestic and semi-professional rock drills weighing up to 5 kg;
• modifications SDS Max and SDS Top for professional grade rotary hammers;
• with anchors and other special fasteners for installation on heavy stationary drilling equipment.

However, the main influence on the performance and strength of the crown design is the material used in their manufacture. Traditionally, drilling holes in concrete walls are performed using core drills with cutting segments:

• from a special composite alloy of high hardness, victorious (alloy of tungsten monocarbide and cobalt in a ratio of 90:10);
• with diamond inclusions or spraying, fixed in electrolyte or by means of laser welding.

How to choose the right one

When choosing a bit for concrete, it is necessary to take into account the type of surface that you have to work with: for unreinforced structures, victorious nozzles are suitable, only bits with diamond dusting can cope with reinforced concrete. Pay attention to the following points:

• the diameter should correspond to the specified parameters of the hole, and the length should correspond to its depth;
• with a large amount of work to be done, preference should be given to models with diamond plating;
• it is important that the crown matches the power of the tool used, the use of large-diameter bits can lead to failure of low-power equipment;
• the shank design must match the mounting system in the drill or hammer chuck;
• the higher the number of cutting segments, the better the technical characteristics of the tooling;
• deep seating of the teeth is a guarantee of strong fixation and durability of the crown;
• make sure that the nozzle is even, has no burrs and defects, and the spraying is strong, applied in an even layer and does not crumble.

Winning modification

This type of crowns has a cutting edge with a victorious soldering. They are intended for drilling concrete exclusively in inter-reinforcement zones and are designed for small amounts of work to be done. Of the operating features, it is necessary to highlight:

• in the process of use, they need cooling, otherwise they quickly fail;
• designed for “dry” drilling, not resistant to sudden temperature changes;
• when hitting a metal rod in concrete, there is a high risk of edge detachment, “sticking out” of soldering;
• concrete nozzles are recognized as a worthy alternative to special crowns for aerated concrete blocks, they are practically not subject to wear.

Victorious modification of crowns is popular among home craftsmen, since with relative strength and wear resistance, its price is 2-3 times lower than the price of diamond-coated tooling.

Diamond core bits

Diamond core bits have many advantages:

• you can carry out work with a shockless method;
• the holes are neat, with smooth edges, without defects;
• suitable for high-speed and intensive work;
• the level of noise, vibration and dust formation is reduced;
• are repairable, their worn edges can be restored;
• cooling of the working part can be carried out by dry (air) and wet (by supplying water to the cutting zone) method.

Of the disadvantages of these modern technologically advanced drilling bits, only their high cost can be noted.

Features of use

In order for the selected equipment to serve for a long time, and the drilling process takes a minimum of time and effort, you should correctly use concrete crowns. Features of operation consist in observing several rules:

• It is necessary to select a crown for the tasks at hand.
• Check the correct assembly of the nozzle. Then install it on a drill or hammer drill, fix it in the drive lock.
• In the presence of a centering drill, its point is set at an angle of 90 ° to the concrete plane. If the crown does not have a drill, then its cutting edge is pressed against the concrete.
• You need to start drilling effortlessly. After making sure that the nozzle is level, you can feed the tool forward with pressure.
• Do not overheat the edge of the crown. Taking breaks required.

It is necessary to perform work in accordance with the above technology, but it is equally important to comply with safety and electrical safety rules. It is important to use personal protective equipment.

Construction of concrete crowns

A concrete crown is a product that has a cylindrical shape with teeth and a shank. The design of the concrete packing is shown in the photo below.

Crowns for concrete for a hammer drill are made of special hard alloys. The center drill, designed to align the bit during drilling, has a victorious tip at the end. For drilling in reinforced concrete structures, it is recommended to use diamond-coated nozzles on the drill tip.

Diamond spraying is applied to the teeth of a cylindrical nozzle, through which holes are drilled in concrete or reinforced concrete of the corresponding diameter. For drilling in concrete, bowls with victorious teeth are used. The special design of the crown shank indicates that the device is intended for use on hammer drills only. The presence of a fixing bolt fastening on the nozzle allows for changing cylindrical bowls of different diameters. This makes such a nozzle not only universal, but also economical.

Crowns for concrete for a hammer drill how to choose the right one

If you need to get a hole in concrete or reinforced concrete, you will need to use a powerful and massive tool. This tool is a perforator, in the chuck of which the corresponding drills of certain diameters are installed, depending on the technological task. These drills are called concrete drill bits. When buying crowns, it is important to know what exactly products are needed for a perforator, since they have distinctive features of the tail section.

Choice of crowns and what to look for

In addition, when choosing, it is important to consider the following information:

• Diameter of the bowl of the product. Depends on the size of the hole to be drilled in the wall. If you need to get an accurate hole in the wall up to 1 mm, then when choosing, take into account the fact that the diameter is several millimeters larger due to protruding teeth
• Cooling method. Does not play a big role, unless you plan to drill holes in reinforced concrete or granite
• The type of material from which the cutting teeth are made. It all depends on what material is planned to be drilled with a bit.
• Cost. An important factor characterizing the quality of the device. However, you need to understand that even if the product is very expensive, but it is incorrectly selected for drilling the material, this will lead to its damage.

The manufacturer also needs to pay attention if there is a desire to get a quality product at a high price. However, remember that it is not only branded products that can be of high quality.

Where are concrete crowns used?

The main area of ​​use of concrete drill bits for a hammer drill is construction and electrical work. With the help of a drill, holes up to 26 mm are drilled with a perforator, and large sizes are needed for sockets and switches. They can only be obtained with the help of punch crowns. Nozzles are available in different diameters, therefore they are used for drilling not only blind holes in concrete, but also through holes.

Through holes are needed for laying heating pipes, water supply and other types of communications. The diamond core bit is used for drilling holes in reinforced concrete structures, as well as asphalt and granite.

Advantages of concrete drill bits for rock drill

Like any other type of tool, concrete drill bits for a hammer drill have a number of advantages due to which they are used when drilling holes. These benefits include:

• Prompt implementation of the task. The use of crowns allows you to drill holes of large diameters, unlike drills and drills
• No need to apply physical force. If earlier only tools such as a chisel with a hammer were used to install the sockets, today they have been replaced by crowns with a perforator.
• High positive result. The drilled hole in concrete or reinforced concrete is smooth and neat
• Cost. Despite all the advantages of the products, the cost of attachments is affordable, and therefore absolutely any home craftsman can afford to purchase them.

Very often, holes are drilled with crowns with victorious teeth in reinforced concrete walls. This causes the teeth on the nozzle bowl to break off. To prevent this from happening, for reinforced concrete, granite and asphalt pavement, it is worth choosing products with diamond spraying.

Varieties of concrete crowns for perforators

Nozzles are made exclusively from carbide types of materials, which make the product strong, durable and effective. Often newbies ask the question, why does the crown have a center drill? Thanks to this drill, you can make precise holes. The absence of such a drill will result in vibrations during the drilling process, so the hole will be distorted, uneven and deformed.

Crowns for concrete for rock drills are divided into types depending on the design of the shanks. They are of the following types:

• SDS-plus. products that are installed in rotary hammers for domestic use
• SDS-max. used only in professional rotary hammers. Shank diameter is 20 mm
• Hexagonal shank shapes. this type of crown is used for drilling large holes with a drill

The crowns differ from each other in the material of which the cutting part (teeth) is made. There are three types of products:

• Pobeditovye. the basis for the production of teeth for the nozzle is an alloy of tungsten and cobalt in a ratio of 92% and 8%. Distinctive features of such nozzles are resistance to high temperatures and prolonged loads. They are used to drill holes in concrete or brick.
• Carbide. this product option is budgetary, and is intended only for making holes in concrete bases. Contact with metal leads to failure of the teeth of carbide bits
• Diamond ones are one of the most expensive, but at the same time effective. They are used for drilling holes in concrete, granite, reinforced concrete and other heavy materials.

It should also be noted that crowns differ in the way they are cooled. They are dry and wet. The attachments that have holes in the sides of the bowl are dry. Wet is a closed version of bowls, which must be moistened with water during the drilling process.

Depending on the drilling method, bits are also subdivided into impact and non-impact bits. The latter option is only suitable for work in drilling mode, and is often used for drills. Impact crowns can be used as a jackhammer on a hammer drill.

How to avoid injury when working with a drill bit

Safety precautions must be followed to avoid personal injury when working with a crown or power tool. When drilling, consider the following guidelines:

• Always before starting work, make sure that the product is securely fixed not only in the tool holder, but also tightly clamped with the fixing bolt (for collapsible products)
• Work must be carried out in safety goggles, as during drilling, fragments of materials can get into the eyes
• Use a respirator, as dust is generated during work
• Moisten the drilling site before drilling to reduce the likelihood of dust formation
• You need to work in special rubber gloves, since woolen products can catch on during the rotation of the cartridge, which will lead to winding them together with your hand onto the working part. This could lead to serious injury.

The drill bits for concrete have a fairly long service life. If you need to use the attachment once, then you do not have to buy a branded product. Only with the right approach to the selection and use of nozzles, you can extend their service life.

Spindle speed and impact frequency

The speed of rotation of the tooling depends on the speed of the spindle. This indicator is inversely proportional to power. Rotation is necessary to remove cuttings generated during drilling from the hole.

If the master more often uses a hammer drill for drilling holes, it is better to give preference to a model with an indicator of up to 2000 rpm. For drilling, a high rotational speed is not needed and a perforator with a spindle speed of up to 1000 rpm is suitable.

Impact frequency is one of the most important indicators of a rock drill. The higher this value, the faster drilling will take place.

Impact power and energy

Professional models have an impact energy of 7 to 27 J. The higher this figure, the more productive and durable the tool. The power of the professional type tool is from 1 kW.

Such equipment has a wide range of functions:

• drilling holes, including those with a diameter over 100 mm;
• drilling of natural stone;
• chipping of concrete when expanding openings;
• creation of a gate for laying communications.

Power tool or cordless tool

Professional builders, repairmen have to work in different conditions. If the site is small, it has a stationary power supply system, it is better to give preference to network models.

Cordless rotary hammers are used on sites where there is no access to the mains. Such models are used when performing work at height, in a confined space. Also, the cordless hammer drill is more convenient to use if you need to drill holes along a long fence or building facade.

The performance of a professional cordless power tool is on par with some corded models. The only drawback of battery technology is the limited operating time. Therefore, it is better to purchase models with two batteries or purchase one more battery additionally. While one battery is being charged, you can continue to work.

A hammer drill with a battery is chosen by installers of ventilation, windows, air conditioners, and other workers traveling to different objects.

AEG PN 11 E

Pros of AEG PN 11 E

• The manufacturer provides for the AVS system, which reduces vibrations by 50%. This reduces the burden on the hands of the master.
• Strong technique, capable of not only creating holes, but also making openings in very hard materials.
• The tool does not heat up during operation. Even after prolonged use at high loads, the housing remains slightly warm.
• When jammed, the stop mechanism is quickly triggered.
• Long service life. Even when worn out, the tool lasts much longer than the warranty period.

• It’s hard to work in a horizontal position.
• When used in jackhammer mode, the handle may loosen gradually.
• The hammer is too heavy (11.8 kg). Some masters claim that a tripod is indispensable.

Output. This is a powerful power tool that is used when carrying out heavy work related to crushing and drilling. Mainly used in an upright position.

Impact mechanism type

In rock drills, one of two types of percussion mechanism can be used: pneumatic or electromechanical.

Pneumatic impact mechanism

The principle of its operation is that the piston of the drive mechanism compresses the air cushion. The second, free piston, is surrounded by air on both sides. It moves forward to the striker, transferring the created force to it.

The actuator piston then moves backward. At this time, the free piston is repelled from the striker, which moves back. Compression of the air cushion on the other side of the free piston increases, causing the actuator piston to stop.

Under the influence of high pressure, the free piston flies back to the striker at an increased speed. The impact is transmitted to the tooling during the operation of the tool.

Watch the video on the principle of operation of the pneumatic type impact mechanism:

Important! Choosing a hammer drill for professional use, you should give preference to the pneumatic type percussion mechanism.

Electromechanical impact mechanism

The electromechanical system that creates an impact force is often used in light models. In such systems, the lever spring is driven by an eccentric. It moves the striking device back and forth. Through a special striker, the force is transmitted to the rig. Recoil is absorbed by the spring, amplifying as the mechanism is moved forward. This system is less robust, does not apply to prolonged, high loads on the tool.

Watch the video on the principle of operation of an electromechanical type percussion mechanism:

Bosch GBH 5-40 DCE

Professional grade corded rotary hammer with 1150 W motor. The spindle speed is 170-340 rpm, and the impact frequency is 1500-3050 bpm. The impact force of the tool reaches 8.8 J. Using the Bosch GBH 5-40 DCE perforator, you can drill holes in concrete with a diameter of up to 55 mm with a drill, and up to 90 mm with a crown.

Pros of Bosch GBH 5-40 DCE

• A powerful enough tool that at the same time weighs relatively little.
• Holes can be created quickly even in very hard materials. On hard concrete, you can work for an hour without turning off the hammer drill. Under increased load, the number of revolutions does not change.
• High-quality German assembly, which ensures durability, endurance of the power tool.
• Large power reserve expands the functionality of the rock drill.
• High-quality anti-vibration system reduces stress on hands.
• The engine starts smoothly, it is possible to adjust the speed.
• When jammed or overloaded, protection is triggered.
• A convenient case holds not only a power tool, but also all the necessary drills, crowns.

• The tool gets very hot. In winter, the cooling process does not take much time, but in summer you have to take breaks up to half an hour.
• There is no reverse, which complicates the extraction of the drill.
• After many years of operation, the number of revolutions may change slightly under load.
• No drilling mode.

Output. In general, this is a workhorse that copes with the tasks assigned to it. It is used in the process of construction, repair of various objects (houses, garages, fences, etc.).

Electronic and brush reverse

The reverse function is provided in many modern models of professional grade rotary hammers. In this mode, the drill moves in the opposite direction, which makes it easy to extract it from any material.

The following types of reverse are used in rotary hammers:

• Electronic. The position of the brushes does not change with this type of reverse. The direction of the torque is changed electronically. Because of this, the power drops, and the brushes wear out faster. Electronic reverse is used on inexpensive models of household perryators.
• Brush. This is a more advanced reverse system. Switching is done by turning the brushes, which avoids a drop in power. The mechanism is more complex, which increases the cost of the equipment. But for professional use, it is more advisable to choose a brush reverse.

Rock drill rating for reliability. comparison of the best models for home and professional use

Bosch GBH 2-26 DFR

The device, which the manufacturer himself positions as a model of the “Professional” class, which shows its ability to long-term continuous operation. Its 800-watt electric motor produces 900 rpm, with the possibility of electronically adjusting their frequency, and there is also a reverse function. In the punch mode, 4000 blows are made on the working surface for a minute, but the device can also be used as a drill or screwdriver. an adapter for conventional drills is included in the kit. Drills with a diameter of up to 26 mm are used.

Pros of Bosch GBH 2-26 DFR

• There is no ruler on the depth gauge.
• The drill chuck does not tolerate the adhesion of concrete dust. it is advisable to store it in appropriate conditions.
• Expensive to renovate. If the perforator breaks down and this is not a warranty case, then the repair will not always be advisable.

Such a device will be a reliable assistant for frequent small works. Suitable for home and professional use. The main thing is not to try to use it in cases where you need a very powerful hammer drill. It will probably cope with this kind of work, but it will greatly affect the overall lifespan of the device.

Makita HR2470

Universal three-mode rotary hammer for work on concrete, brick and similar materials. The ergonomic design of the handles maximizes vibration absorption. It is equally convenient for left-handed and right-handed users. Electric motor power 780 watts. Rotation speed 1100 rpm. there is speed regulation and reverse. In chiseling mode, 4500 blows are made on the working surface.