The design of a hammer drill chuck - what are manufacturers hiding? Repairing a rotary hammer with your own hands is not as scary a process as it seems

A rotary hammer is an almost indispensable piece of equipment for performing a number of construction and other tasks. When choosing such a reliable friend and assistant, first of all, you need to decide on the design of its cartridge. During operation, any master may be faced with the need to remove and replace it in order to install new attachments or repair the tool itself. For professionals, replacing a cartridge in a hammer drill - simple task, which can be solved easily and quickly. But, if you are faced with a similar problem for the first time, then you should familiarize yourself with some recommendations in advance, which will be described below.

Before proceeding to removing and replacing the cartridge, it is necessary to determine in advance its type that is used in this device. Experts identify the following types of cartridges, which are most often found in modern models of rotary hammers:

• SDS collet chucks;
• key or jaw chucks;
• quick-release chucks.

SDS chucks for rotary hammers

Translated from German language The abbreviation SDS stands for – Steck – Dreh – Sitzt or “insert, turn, done.” Chucks of this type have guide wedges and locking balls in their design, which ensures very fast and reliable fastening. They are very convenient to use, easy to remove and replace with new ones if necessary. To do this, you just need to turn the cartridge. There are SDS-max, SDS-plus, SDS-top cartridges.
They differ from each other in the working diameter of the nozzles that can be attached to them.

1. Thus, SDS-plus are installed in light and medium-sized models of rotary hammers for attaching bits with a working diameter of no more than 26 mm.
2. SDS-max rotary hammer chucks are found in medium or heavy-duty rotary hammers with a working drilling diameter of more than 20 mm.
3. SDS-top is not as common as other types of chucks and is designed to mount bits with a drilling diameter of 16-25 mm.

SDS collet chucks provide deeper drill fixation and are installed in most modern models hammer drills that combine the functions of drilling and striking. For devices with only one drilling function, jaw or keyless chucks are suitable.

Jaw or key chucks for hammer drills

A key or jaw chuck involves installing a drill using a special tool or key, which is sold in the kit. This is the most common type of cartridge today and has an affordable price.
It is suitable for large drills and powerful devices that require secure attachment of the bit. However, the main disadvantage of such a chuck is the inability to replace the drill if the key is missing or accidentally lost.

Keyless chucks for hammer drills

Keyless chucks are convenient and easy to use. The drills in them are installed without a key, unlike cam drills, so changing the bit is done quite quickly and without any effort. This type is most suitable for those who, during work, have to very often change the equipment of the hammer drill, performing several operations at once. At the same time, the cost of a tool with a quick-release chuck is slightly higher than that of others.

The process of removing a chuck from a hammer drill

After the type of cartridge that is installed on the hammer drill has been determined, they proceed directly to its removal.

• To do this, you will need a standard set of tools that can be found in almost any home: a hammer, a screwdriver and a key. As a rule, cartridges are attached using a so-called spindle or screw rod.
• First unscrew the screw. To do this, open the clamping chuck. In most cases there should not be any difficulties here. However, if the screw still doesn’t give in and you can’t immediately remove the cartridge, then experienced craftsmen recommend tapping with a hammer on top of the screw head. This way, you can loosen it, and then try to use the screwdriver again.

• Next, the cartridge is clamped in a wrench or taken in a vice with plastic jaws, and the spindle is turned. Without key cuts, you can try to fix the spindle inside the device itself, although this is much more difficult.

Replacing a hammer drill chuck

• After removing the old cartridge, the new cartridge is screwed onto the hammer drill until it stops.
• Then insert the screw back into the socket and tighten it until it stops. Thus, all the manipulations with the cartridge that were listed above are performed, only in reverse order.
• Replacement can be made with a cartridge of a different type. The main thing is to decide in advance which one you will need in your work.

So, we looked at the design of cartridges, their main types, advantages and disadvantages, as well as operations that can be carried out with them. In addition, the process of replacing and installing a new hammer drill chuck was described step by step. As it turned out, solving such a problem is quite possible for each of us. Especially with the right approach and taking into account all the recommendations of specialists.

It's no secret that tools have different powers. For hammer drills with high power, a chuck with reliable fastening of a drill or drill is required.

In construction, there are key and quick-release chucks. In key ones, the attachment (drill, drill, cutter) must be fixed using a special key that spreads the fingers. In quick-clamping ones, the attachments will be fixed manually.

How to remove them from the hammer drill and do the repairs yourself? Many people ask about this.

To remove a collet or quick-release clamp from a power tool, simply turn the drill. You must learn how to disassemble a hammer drill chuck with your own hands.

If the attachment is firmly fixed, then removing the clamp from the power tool is very difficult, and sometimes almost impossible. How to remove the cartridge from the hammer drill in this case?

This must be done using a hammer, wrench and screwdriver. The disassembly process will be carried out in the following order:

1. Start by tapping the head of the screw to loosen it.
2. Then gradually begin to unscrew the nozzle using a screwdriver.
3. After unscrewing, clamp the cartridge in a vice and begin to turn the spindle.

If after removal you find that the cartridge has become unusable, then it must be replaced. To change the clamp on a hammer drill, perform the following manipulations:

1. Screw the chuck onto the drill until it stops.
2. Then insert the screw into the socket.
3. After insertion, gradually tighten the screw using a screwdriver until it stops.

Do not forget to disassemble and clean the hammer drill from time to time. This will help you avoid significant problems in the future. Also, sometimes there is a need to make minor repairs to the cartridge yourself, for example, replace a spring.

Switching hammer modes

For normal use of the tool, you must understand that there are several operating modes:

1. The first of them is drilling. When working in this mode, you must:

• switch the toggle switch for selecting hammer drill modes opposite the drill mark;
• then insert the drill bit and turn on the power tool.

If you don't know how to insert a drill into a hammer drill, then we will explain to you.

To install a drill in a cam or collet device, simply push the drill into it. Then insert the key into the special hole on the outer part of the chuck and scroll until the drill is fully clamped.

During operation, you do not need to press hard on the nozzle.

Advice: When using the chuck in drilling mode, never switch the toggle switch to “counterclockwise rotation”, as this may damage the attachment.

To prevent impacts, rotary hammers have a locking function. It is usually used when drilling holes in wood or metal structures.

It is advisable to let the hammer idle for a couple of minutes before inserting the drill into the hammer drill. Be sure to check the gearbox. It should not make extraneous noise or knock. Otherwise, have it repaired.

1. The next mode is called hammer drilling. How to operate a hammer drill in this mode? The answer is simple - with the drill and hammer toggle switch turned on.

During operation, carefully monitor the drill:

• it must not be distorted;
• During this mode, you should hold the hammer firmly, but not pressing too hard.

Remember that when drilling concrete you may stumble upon pieces of reinforcement, so take a comfortable position in advance so as not to lose control of the tool.

1. The last variation is the impact mode. Typically, it is used for chiseling or chipping operations. Sometimes it is used for gating.

Before starting work, switch the hammer drill toggle switch to the mark with the image of a hammer. Remember that in this mode the tool must be held very firmly.

Advice: Before turning on the power tool, move it to the desired location for impact.

How to use a hammer drill correctly

For proper operation With power tools you should remember the following techniques:

1. Be sure to use personal protective equipment. Namely: glasses, gloves, earplugs. Immediately before work, remove all foreign objects that could become entangled in the drill.
2. Do not press too hard on the instrument, otherwise you may damage it.
3. Don't forget how to use a hammer drill correctly. Do not “drive” it idle for more than 4-5 minutes. In this case, you expose the chuck mechanisms to a lot of wear.
4. If you are working with porous or loose materials, it will be more reliable to work in hammerless drilling mode.
5. If you are drilling with materials that have high hardness, use a special lubricant or machine oil.
6. Don't forget about liquid cooling if you're working with hard materials. All kinds of emulsions or grease can be used as liquids.
7. If you are working with long drills, in order to save money, start working with shorter drills of the same diameter.
8. To prevent the tool from needing repair, be sure to lubricate the drill shanks with thick grease every 100-150 holes. But do not forget about pre-cleaning them from dust and dirt. Experts recommend using grease as a lubricant.
9. Let the hammer cool down periodically. Sometimes dip the drills in water or oil.
10. When working, pay special attention to ensure that the gearbox is not overheated. If you notice heating, take a short break from work. However, you should not put the power tool in water - it will give you an electric shock.
11. Don't forget how to use a hammer drill. Take care of your hammer drill before and after use. Remember that the life of the instrument depends on the quality of care. Clean construction dust from power tools using a vacuum cleaner. To protect the drill, you can put a special shield on it, which can even be made from plastic bottle. Be sure to follow the operating and rest schedule of the tool. It is advisable to take a 10 minute break after every half hour of work.
12. Keep a close eye on the hammer drill vent.
13. Once a month, disassemble the hammer drill and perform a preventive inspection of the gearbox.

In 1980, BOSCH provided power tool manufacturers with new concept SDS quick change chuck. This abbreviation means Steck-Dreh-Sitzt (free translation into Russian - insert, turn, sit). And it sits really tight. Over the 25 years of its existence, there has been no need to improve the design of the cartridge.

The developer did not monopolize the design, but sold competitors the right to use the technology. Thanks to this, the design of the SDS quick-release chuck has received a unification recognized by all market participants. Tools from a variety of manufacturers are equipped with such cartridges, and there are countless factories that produce attachments.

keyless chuck for hammer drill

There are hammer drills with other types of cartridges. For example, collet, cam, with rigid fixation of the tool. On modern market household power tools are rather exotic.

Or such cartridges are used in professional instrument. A home handyman on the go needs to remember the abbreviation SDS.

For the right choice perforator by type of cartridge, and subsequent purchase of tips (drills), consider the loads and designs of existing cartridges.

The hammer drill chuck is constantly subjected to torsional and shock loads. This places high demands on manufacturing quality.

IMPORTANT! The instructions for any hammer drill instruct you to always lubricate the working tip before installing it in the chuck. If you do not do this, the part will quickly fail.

One thing saves - the cartridge can be serviced and replaced. At the same time, the whole trick of the design is that the locking mechanism itself does not experience stress loads. And the stop, to which all impacts are transmitted, is a monolithic unit that is motionless relative to the structure.

Therefore, the cartridges in the hammer drill serve for a long time and trouble-free, subject to timely maintenance and lubrication.

What types of cartridges are there and what is the difference?

Since rotary hammers are produced in two main weight categories - “heavy” and “light”, the cartridges also have two main modifications.

When choosing a chuck for a hammer drill, the buyer must understand the design of such a clamping device. This will allow you to immediately resolve questions about which tool in the kit can be used with a hammer drill and what types of processing can be performed using such equipment. In addition, knowledge of the structure of the hammer drill chuck allows you not only to independently replace the clamping device, but also to carry out its simple repairs, if the need arises.

How do chucks for hammer drills work?

To effectively use different hammer drill bits, you need to ensure that they are securely attached. A special cartridge is used for this. Its first models began to be developed back in the 30s of the last century, when hammer drills appeared on the market, the mass production of which was mastered by the world famous company Bosch.

Such a manual device as a hammer drill was almost immediately appreciated by consumers, since it can be used to combine drilling with pulse chiselling, which significantly increases the efficiency of the processing performed. The main drawback of the first models of rotary hammers was precisely due to the fact that the weakest link in their design was the cartridge, which quickly became unusable under the influence of shock loads.

As a result of long-term development, manufacturers of hammer drills and chucks have come to the following conclusion: the simpler the design of the clamping device, the more reliable it is in operation.

As a result, three main types of cartridges for rotary hammers were created, which in turn are divided into subtypes.

Gear-crown (key)

There are chucks in which the working attachment is fixed using a special key that activates cams that reliably clamp the shank of the tool being used. The most significant advantage of this type of chucks is that they provide reliable fastening of the tool used in conjunction with the hammer drill. Meanwhile, to replace the working tool in such a chuck for a hammer drill, you will need to spend significantly more time than when using other types of clamping devices.

Quick-clamping (BZP)

The working attachment of the hammer drill can also be fixed on it using a quick-release chuck (KLC), which is activated only by the force created by the operator’s hands. Depending on the design, cartridges of this type can be single- or double-clutch, the operating principles of which also differ.

Single-socket chucks are easier to use, but they can only be used in conjunction with drills that have the ability to automatically lock the working shaft. To activate such a cartridge, the effort of one hand is sufficient. To use a double clutch clamp, you need to hold the rear clutch with one hand and rotate the front clutch with the other.

What is SDS

SDS (SDS) is an acronym made up of the first letters of the words Steck, Dreh, Sitzt, which translated from German mean “insert, turn, secured.” It is on this simple, but at the same time ingenious principle that the SDS cartridge, developed by Bosch engineers in the 80s of the last century, works. Today, 90% of all manufactured rotary hammers are equipped with these easy-to-use devices, which ensure high reliability of fixing the working tool.

SDS chucks are often called quick-release chucks, but they should not be confused with devices in which clamping is achieved by rotating the couplings. Unlike traditional quick-release chucks, The SDS clamp does not need to be rotated to secure the tool: you just need to hold it with your hand.

To understand the design of a hammer drill chuck of this type, as well as the principle of its operation, just look at the tool shank, which is designed to be fixed in such a device, or the SDS adapter. This shank has 4 grooves, two of which are open at the end of the shank, and the other two are closed. Open grooves act as guides; they ensure the correct position of the tool when it enters the chuck. The closed grooves, in turn, ensure the fixation of the shank in the hammer drill chuck.

In the inner part of the SDS cartridge there are special balls that perform two functions simultaneously. At the moment when the tool is just inserted into the hammer drill, the balls along which the guide grooves move ensure its correct position. After the tool is inserted all the way, such balls fix it, for which it is necessary to turn it a little until the balls enter the closed grooves of the shank. To make using the SDS chuck even easier, it is recommended that the tool shank not only be thoroughly cleaned after each use, but also lubricated.

It should be borne in mind that due to the design features of SDS chucks, the tool that is fixed in them is subject to slight radial runout at idle, which does not in any way affect the accuracy of the processing performed. Meanwhile, the presence of a small play between the shank and inner surface The cartridge protects the latter from the impact to which drills and drills are exposed during the operation of the hammer drill.

Types and scope of application of SDS cartridges

Depending on the diameter of the shank with which the tool or adapter is equipped for fixing it on the hammer drill, SDS chucks are divided into five main types: regular SDS chucks, models of the SDS-top, SDS-quick categories, as well as SDS-plus and SDS-chucks. max. The most popular are the SDS-plus category chucks, which are designed to hold tools with a shank diameter of 10 mm. The shank of the tool, adapted for fixing devices of the SDS-plus category, enters them to a depth of 40 mm. In this case, the diameter of the working part of the tool, which is fixed in SDS-plus chucks, can be in the range of 4–26 mm.

The maximum tool length that can be clamped in SDS-plus chucks is 1 meter, and its most common working diameters are in the range of 6–12 mm. Devices designed to hold SDS-plus shanks and corresponding adapters for rotary hammers in them are used to equip light and medium category equipment, the weight of which, excluding the weight of the tool, ranges from 3 to 5 kg. It is precisely these hammer drills, which are designed for impact loads of up to 5 J, that are most popular among home craftsmen and small repair teams.

SDS-max chucks, with a bore diameter of 18 mm, are used to equip heavy professional rotary hammers, whose weight starts from 5 kg. Such hammer drills, which can be used in conjunction with tools with a working diameter of up to 6 mm, are able to create an impact load of up to 30 J. To ensure accurate and reliable fixation of the tool in such serious equipment, an additional guide groove is provided on shanks of the SDS-max category .

SDS-top and SDS-quick chucks are intermediate options for equipping rotary hammers and are used much less frequently than the models described above. Meanwhile, the design of SDS-quick devices, which were developed by Bosch engineers in 2008, is worth a closer look. The tool is inserted into the SDS-quick series chucks not using grooves, but through protrusions on the shank. The design features of SDS-quick chucks allow them to hold tools with a hexagonal shank and a quarter-inch size.

How to disassemble and assemble a cartridge yourself

To perform Maintenance and repairing a hammer drill chuck with your own hands, it is important to properly remove and disassemble this device. Knowing how to disassemble a hammer drill chuck (or how to disassemble a drill chuck), you will be able to independently inspect, clean and even make minor repairs to its internal elements, which will allow you to always maintain your tool in good technical condition. The simple design of SDS cartridges allows them to be removed and disassembled even by people who are not comfortable with technology.

So, disassembling the classic SDS hammer drill chuck is performed in the following sequence.

Step one

The plastic part is removed from the cartridge and the rubber seal is removed.

Step two

Using a screwdriver, remove the retaining ring and then the retaining washer.

Step three

When the locking washer is removed, you can see a second ring underneath it, which also needs to be removed using a screwdriver.

Step four

After all the rings and washers have been removed, you can begin to disassemble the SDS mechanism, which consists of a washer, a ball and a spring. First of all, it is necessary to remove the ball from such a mechanism, then the washer and only then the spring.

Repairing a rotary hammer is complicated due to the layout of the units with mechanical interface and power unit. All parts have micron tolerances and a proven sequence of actions. Therefore, it is necessary to ensure proper care and technical operation tool in accordance with the requirements of the instructions, thereby extending the overhaul period.

Perforator device

There are few tool users who have studied not only the order of pressing levers and buttons, but also understand what happens in the mechanism as a result of the command received. Without knowing the interaction of the components, it is impossible to perform even the smallest repair of a rotary hammer.

There are signs of problems that relate to the power part, and sometimes mechanical wear or breakdown of parts occurs.

Electrical circuits and equipment are concentrated in one part and are presented in section in the photo.

Signs of a malfunction that require replacement of parts or repair of the rotary hammer in the power section may be the following:

• when the device is turned on, the mains fuses trip;
• the device does not turn on;
• During operation, smoke with a pungent odor appears;
• the device sparks during operation;
• speed is not adjustable.

You can find the reason why the device does not turn on using a tester. You need to look for a gap in the scheme, from simple to complex. Check connections, clean contacts. The most complex and expensive part that fails may be the hammer drill armature. This is the heart of the engine, made up of copper coils interconnected and fastened with lamellas. If the insulation breaks down anywhere between the wires, a short circuit occurs and the entire collector needs to be rewinded or replaced.

You can determine that the armature on a rotary hammer is faulty visually by a burnt winding, traces of smoke on the lamellas, or by testing for a short circuit. Damage can be prevented by timely maintenance and cleaning of parts from dust, which is the root cause of all troubles. If sparking comes from the engine, the armature must be cleaned with an alcohol swab or a regular school eraser to remove graphite deposits from the collector.

The second important part of the engine is carbon or graphite brushes. It is through the moving contacts that the electric charge on the core, creating an induced EMF torque. The rotary hammer brushes are the contact that connects the rotating commutator to the power source.

The two elements always work in tandem. A carbon or graphite plate is pressed against the collector. As a result constant friction On the rotating collector, the plates wear out and contact is broken. A sign of a malfunction will be sparking in the manifold; perhaps the engine does not develop speed. Regardless of the state of wear, both plates are replaced at the same time. Most tool models have brush wear indicators that warn the user in advance.

The revolutions of the rotary hammer may not be regulated due to a malfunction of the control unit, then it needs to be replaced; the device cannot be repaired.

Mechanical faults and their elimination

To find a particular malfunction, you need to get to the desired node. Any of the sequentially removed parts is carefully inspected for the presence of:

• cracks;
• chips;
• burrs or scratches.

In most models, they are disassembled into two halves, but each of the hammer drills has its own characteristics. How to properly repair a rotary hammer with your own hands, watch the video:

A sign of a breakdown may be:

• refusal to perform a function;
• extraneous sounds inside the mechanism and excessive heating of the case;
• modes do not switch;
• grease is leaking.

Each of the symptoms may be the result of a breakdown of any of the parts that are removed in the sequence indicated in the diagram. Reassemble the tool in reverse order. Spare parts should be purchased according to the specifications in the service instructions.

One of the causes of mechanical breakdowns is often insufficient maintenance of a unit operating in difficult conditions. Preventative measures are not complicated, and the life of the instrument will be significantly extended. According to the operating rules it is necessary:

• renew the gearbox lubrication every six months;
• after 6 months, inspect and clean the brushes and the adjacent part of the commutator;
• at the end of the working day, clean the rotary hammer with a vacuum cleaner;
• do not forget to apply lubricant to the shanks of the slotting equipment to seal against dust and prevent wear of the socket.

Do not apply physical effort when working with a hammer drill; the hammer and seals will wear out, causing fatigue and irritation for the operator.

Goals and objectives of tool lubrication

Often the cause of tool failure is the absence, deficiency or inappropriate lubrication. Abrasive wear is reduced if all gaps and cavities are covered with a layer of antifreeze, and cleaning is carried out in a timely manner.

The type of gear lubricant differs from the composition for the shanks. Each manufacturer recommends using a specific hammer drill lubricant specified in the instructions at the required frequency.

There are general recommendations that apply to all rotary hammers. Gearboxes must receive oil of liquid consistency, poured into a special hole. For all units, you can undoubtedly use Bosh and Makita lubricant intended for gearboxes, which is what they do in service centers.

Incorrectly selected or overfilled lubricant can lead to overheating of the gearbox.

To lubricate the shanks of the working equipment before inserting it into the chuck, a lubricant of a thicker consistency from the same manufacturers is used. In this case, the attachment point for the shank in the chuck and the firing pin are protected from wear. Filling all gaps with lubricant protects the assembly from dust.

It is necessary to lubricate the places indicated in the instructions. And it is certainly harmful to add lubricant to the clutch. In case of sudden detection of a lack of lubricant in the gearbox, you can use the domestic composition, Litol-24 Lux, but lubricant is not suitable for battery-powered hammer drills, even temporarily.

Design of the working unit and equipment of the hammer drill

The hammer drill has a chuck into which the working tools are secured. For professional heavy hammer drills, SDS max chucks accept only 18 mm diameter shanks with five longitudinal grooves, which are installed in the chuck socket of the corresponding profile.

The light and medium tool is equipped with an SDS plus chuck, which allows the use of a slotting tool with four longitudinal grooves and a cross-section of 10 mm. The hammer drill chuck is designed so that it can only accept tools designed for it. If you insert the wrong accessory, it will not fit into the socket, or it will be installed sideways. If you try to work, the fastening unit will be destroyed. But drills do not have a fluted shank. An attached cartridge is used, which is installed in the SDS profile. But at the same time the tool lengthens. The drill chuck for a hammer drill can be a quick-release chuck or a key chuck. The adapter is used only with an SDS+ chuck, since a more powerful hammer drill does not have the function of drilling without impact.

A hammer drill is a multifunctional tool. It can use modes:

• shock;
• impact with drilling;
• drilling, if there is a special chuck.

To work in shock mode, there are many devices used to facilitate manual labor.

Drilling impact is performed only with the use of hammer drill attachments:

• hollow crown;
• paddle for scoring.

They call it a tool that has a special profile shank, a working part that is a screw and a tip made of special steel with a centering tip. The destruction of the material occurs not by scraping, but by chipping the rock. At the same time, an impact with rotation occurs, as a result of which the chipped pieces are removed along the screw surface of the working part.

Drills for hammer drills are installed when working in non-impact mode. With this tool, a lightweight hammer drill can work like a regular wood drill. If necessary, the device can be used to tighten fasteners if a reverse function is provided.

A hollow crown is needed for making through passages for cable wiring or for creating recesses in the body of a structure for installing devices. The crown creates a circular passage, leaving a post in the middle. Since the nozzle has a special toothed profile, metal reinforcement in concrete will render the cutters unusable.

Recesses in the wall can be made with a special spatula for grooves, but the holes will not look as neat as those made with a crown.

The bushard has long been considered a sculptor's tool. The craftsmen used forging and cross bush hammers. This percussion instrument, resembling a hammer, the head of which is serrated. Using a bush hammer, the sculptor cut off everything unnecessary from the stone block, and with a cross hammer he gave the shape to the stone.

When using one impact mode, use with attachments:

• spatula or flat chisel;
• peak;
• channel chisel;
• bush hammer

The hammer drill blade is designed to level the surface of hard material. Using this equipment, you can remove tiles from walls and remove uneven surfaces from hardened concrete. Correction of some flaws when installing openings in multi-story construction is carried out using this tool. A hammer drill chisel used for concrete can have different widths, depending on the task being performed. Suitable for all rotary hammers. Specially created, narrowly targeted attachments are also used - a chisel, a tamping plate or a mortar cutter.

When dismantling building structures it is necessary to create a breaking force. To destroy a wall or partition, concentrated at one point, the impact of the lance is provided by the power of the hammer drill.

Bucharda is a molded attachment, a very durable sledgehammer. The teeth on the bush hammer are carbide and can withstand heavy shock loads. Removing a layer of concrete from a wall, knocking off a layer of rust from metal - this is the area of ​​application for bush hammers. If you treat the walls with this tool before plastering, no reinforcement will be required. You cannot use a bush hammer for a rotary hammer in the mode of rotating the tool. The inevitable consequence will be jamming.

Rules to follow

During operation, the hammer drill heats up quickly. In order to maintain the functionality of the tool for a long time, it is necessary to take a break of at least 10 minutes after 20-30 minutes of work.

In the process of work, when turning the tool idle, you need to remove crumbs and dust, clean the hole being punched in order to make the tool easier to work with. When drilling holes with a large cross-section, first drill with a thin drill, then with a medium one, making the hole in three steps. Long through passages must be drilled first with short nozzles, gradually replacing them with longer ones.

After work, it is necessary to put the punch and used nozzles in order. Tools must be cleaned of dust and placed dry in a container.

Video about self-repair of a rotary hammer