Rating of the best lubricants for rotary hammers for 2021

Lubrication of the hammer drill plays an important role among other procedures associated with the periodic maintenance of this tool. This preventive measure should be carried out after the time specified in the instructions for use. Timely replacement of lubricant reduces friction in the device components, slows down the wear of parts, thereby extending its service life. It should be borne in mind that the old lubricant must be removed when adding a new one. Hammer drill lubricant is produced by different manufacturers. At the same time, various types are intended for its individual nodes.

What parts in a hammer drill need lubrication?

In order to properly maintain a rotary hammer, you need to know which parts to lubricate and how often. This mechanism has a rather complex structure. It consists of the following main components:

• housings with vibration protection;
• an electric motor having a vertical or horizontal arrangement;
• piston system;
• cartridge;
• a gearbox made in the form of a housing (crankcase), inside of which worm, bevel, and cylindrical gears are located;
• a safety clutch designed to stop the rotation (if the nozzle gets jammed during operation) of the chuck;
• working attachment (drill, blades, chisels, crowns or peaks).

The schematic structure of the hammer drill is shown in the photograph below.

A gearbox is a unit responsible for regulating the speed of the working nozzle. Its closed design is designed to protect the parts located inside from dust, dirt and possible mechanical damage. During operation of the tool, the gears experience significant loads, and the friction between them increases significantly. This leads to an increase in their wear rate.

As a rule, for various models of tools, the gearbox comes lubricated from the factory. But during operation, the metal of the parts is destroyed. As a result, metal dust is formed, which, when mixed with lubricant, leads to an increase in friction force (therefore, to accelerated wear). Timely replacement of the lubricant helps slow down the destruction process.

It should also be taken into account that often cheap models are lubricated rather poorly or with material of dubious quality. It is recommended to re-coat them immediately after purchase.

In addition to the transmission mechanism, the cartridge and the seat of the inserted replacement nozzle should be treated with lubricant. The first one is delivered dry. Only the area in direct contact with the shank of the nozzle is coated with it: in this place, strong friction occurs during operation of the tool. If it is not reduced, this leads to increased wear of the cartridge, even to the point of severe damage. Also, the tail part of the nozzle quickly wears out and can be deformed under the influence of impact forces during strong heating, which is caused by friction.

Stator assembly assembly

The stator assembly of the Interskol P-26/800ER hammer drill is no different from the stator assembly of any other hammer drill.

The stator pos. 74 is inserted into the stator housing, secured with screws pos. 73 and closed with a diaphragm pos. 72.

Electrical assembly diagram

The rotor pos. 69 is inserted into mesh with the helical gear of the intermediate shaft.

Assembling the housing of the Interskol P-26/800ER hammer drill

The assembly of the Interskol P-26/800ER hammer drill is completed by installing the stator housing cover pos. 77.

Assembly of rotary hammer housings Interskol P-26/800ER

Installing the brush holder and carbon brushes

Having secured the housing cover, proceed to installing the brush holder pos. 81. Installing the brush holder does not cause any difficulties.

Install carbon brushes, pos. 83, into the brush holder, secure them with spiral pressure springs, pos. 84.

All that remains is to insert the switch button pos. 87, connect the wires to the stator terminals, and hide the wires in the handle of the hammer drill.

Checking the functionality of the Interskol P-26/800ER hammer drill

After assembling the Interskol hammer drill, make sure that the rotor shaft rotates easily by twisting it behind the tool receiver.

Inspect the correctness and uniformity of the carbon brushes. Connect the instrument to a 220 V network.

Turn on the hammer for a short time and inspect the sparking of the carbon brushes.

Install the protective cover pos. 85.

The assembly of other models of Interskol rotary hammers is practically no different and is shown in the video below.

How often should you lubricate the tool?

The nozzle shanks should be lubricated at each installation, after wiping off any dust or other contaminants . If the work is carried out intensively, then you need to visually monitor the degree of lubrication of the seat of the nozzle used.

The hammer drill works with different intensity for different users: some use it every day, while others use it only occasionally. Therefore, there is no clear answer about the regularity of applying or replacing lubricant. To determine the need to change the lubricant in general, you need to focus on the following:

• intensity of tool use;
• recommendations set out on this issue in the instructions for the hammer drill;
• warranty period.

The most complete recommendations from manufacturers regarding lubrication of tool components are contained in the operating instructions. Parts not listed there do not need lubrication.

What it is

Hammer drill lubricant is a viscous, oily, yellowish substance with a specific odor. Why is it needed? Its main function is to reduce the friction force that occurs during operation between the moving elements of the device.

During tool operation, the lubricant becomes saturated with wear products or mechanical dust, which reduces its viscosity. Therefore, the composition must be reapplied periodically.

A lack of lubrication in most cases leads to overheating of the device and subsequent breakdown. However, if an oily composition is applied excessively, the rotation speed of the drill decreases, and this negatively affects the overall performance.

Important! When choosing a lubricant, you need to take into account not only the features of its composition, but also the technical parameters of the device.

Features of selecting lubricant for gearbox, drill, chuck

A lubricant is a substance designed to reduce the friction force between parts interacting with each other. Of course, some friction remains, and during use of the tool, the contacting structural elements continue to wear out. But in the presence of lubrication, the process slows down significantly compared to dry friction.

Lubricants are synthetic, mineral and semi-synthetic. The second type is made from oil. It quickly loses its performance characteristics and needs to be changed more often.

The main parameter of lubricant products is the degree of its viscosity. Manufacturers of rotary hammers, in their operating instructions, recommend using a lubricant with a certain value for this characteristic to care for their tools.

Each brand of lubricant has its own technical characteristics that should be taken into account when choosing. To lubricate the gears, chuck, and nozzle shank, only types of compounds suitable for processing these parts are used.

Thus, the material used to reduce friction in the gearbox is not used to lubricate drills.

To lubricate the hammer drill transmission mechanism, it is recommended to use gear oil. It is poured through a special hole in the housing in the amount required by the instructions. At the same time, it covers interacting parts, filling the crankcase. Hammer drill oil should be of liquid consistency.

Gear oil SX75W90 GL4 1L

The transmission mechanism is also lubricated with special plastic compounds. But you need to take into account that not all equipment is able to work normally when using substances with such a consistency. If the gear parts are (partially or completely) plastic, then it is possible to use silicone lubricant, for example: 220-R Silicone DBC or HVS-100 Silicone #3 from Huskey.

Silicone grease 220-R Silicone DBC

To reduce friction between the tail parts of the nozzles and the cartridges, you need to use compounds of a thick consistency, which indicate that they are intended directly for drills. If there are none, then you can use a graphite analogue. But it removes heat worse than a special composition. Thick varieties of silicone lubricants are also used for cartridges.

Recommended lubricant manufacturers

Lubricant can be used both branded (from manufacturers of hammer drills, for example, Hitachi, Metabo, AEG, Bosch, Bosch, Interskol, Zubr), and from companies involved in the production of lubricants (Xado, Ravenol, Shell and others). The most popular companies with a popular range of products are presented in the table below.

Bosch and Makita gear oils are most popular among consumers.

Bosch grease 3605430008

When using a tool whose quality is confirmed by a special certificate, you should use only lubricants of brands specified by the manufacturer of the device. The use of other materials will result in loss of the possibility of warranty repairs and maintenance of the hammer drill.

Some may have a question: is litol suitable for lubricating a hammer drill? It is due to the fact that this lubricant, in terms of its characteristics, is inferior to specially developed compounds from well-known companies. Litol can be used, but it will need to be changed more often. The best lubricant option is the composition specified by the manufacturer. There will be no problems when using it, incl. with warranty service.

Difficulty of choice

Unlike lubricants for other types of equipment, it is easiest to select lubricant for rotary hammers based not on the composition of the ingredients, but on the specific recommendations set out by the tool manufacturer in the user manual. It specifically states:

• viscosity type;
• type of water resistance;
• compatible types of lubricants;
• possibility of using universal samples.

The issue of quality in this matter depends entirely on the manufacturer. Thus, foreign products are very popular;

Slightly lower in rating (but not always in quality) are products from:

• Shell;
• "Castrol";
• "Ravenol."

Separately, it is worth mentioning the Ultra brand, which is a prime example of the “golden mean” between liquid greases. This means that it can be used in both unsealed and sealed gearboxes.

If you are using an equipment model whose manufacturer did not bother to provide specific recommendations regarding lubricants in the instructions, then it is possible to use some of their universal types. Asian appliances often suffer from this “disease”. However, they are famous for their unpretentiousness: in particular, the substance used to lubricate diesel internal combustion engines is quite suitable for them. Some craftsmen prefer to use graphite lubricants on Chinese models. If the instrument clearly has an amateur purpose, then the domestic “Litol 24” may be suitable for it. However, a professional tool most likely will not tolerate substitutes and analogues, so it must be lubricated only with “original” lubricant in order to prevent the risks of an uncontrolled increase in temperature and excessively sharp braking when stopping. Moreover, the use of “native” material will significantly reduce the requirements for lubrication frequency.

Leading lubricant manufacturers

Before wondering how to lubricate a hammer drill, you need to choose the right product. Having understood the crankcase design and choosing either liquid or grease lubrication, you need to choose the manufacturer. And here you can go one of two ways.

The easiest thing to follow is a brand. Bosch, Makita, Lubcon, AEG are widely popular. In this case, you need to use lubricant from the same manufacturer that manufactured the tool. This ensures that all of the above requirements will be met.

In addition, such lubricants often have accompanying documents, which even indicate specific models that are best compatible with the product. Sometimes there is even a list of other brands whose equipment can use this product. But you still need to be extremely careful in your choice.

Lubricant products from Bosch Source allegroimg.com

You can also use universal lubricants from leading manufacturers. Companies such as Castrol, Xado, Ravenol and Shell produce a line of oils that are equally suitable for any equipment. And the only condition for proper use is that there is an indication on the product packaging that this is indeed a lubricant for the gearbox of a power tool.

The owner can only choose the consistency. And the technical documentation included with the hammer drill will help you do this correctly. There is always complete information there, including recommendations for lubrication of working units.

Causes of equipment overheating

Many home craftsmen have a question about how to use a hammer drill so that its gear housing does not overheat. First of all, you should find out the reason for the excessive heating. One of these reasons may be too much lubricant in the internal part of the gearbox, which also negatively affects the performance of the device.

The reason for the intense heating of the rotary hammer gearbox may also be that an insufficient amount of lubricant is supplied to its internal parts. This can happen in cases where the hammer drill is used for too long in the chiselling mode.

Through this hole in the hammer drill body, lubricant is periodically added during operation.

Another common reason for the device to overheat is that the holes through which cooling air flows to the hammer drill motor are clogged. In such cases, it is necessary to thoroughly clean the rotary hammer from dust and switch it to normal drilling mode for a while. When operating in this gentle mode for about half an hour, the temperature of the gearbox housing should decrease.

With proper care of the technical condition of the rotary hammer and compliance with all recommendations for its use, the gear housing should not overheat under any operating conditions.

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Service frequency

This procedure must be carried out every 3 to 4 months if the instrument is used frequently. If it is used periodically, then it is enough to perform the work once a year.

For proper maintenance it is necessary to use a high-quality lubricant. If the original cannot be found, then an analogue is used. Today there are several brands on the market that produce lubricants that comply with GOST-R.

Thus, processing the rotating elements of the hammer drill yourself is not a problem. You need to follow the instructions and select a high-quality mixture. If the tool was purchased on Ebay or Aliexpress and does not have a brand, then you should choose a lubricant from the list above.

When purchasing a branded hammer drill, use original mixtures to extend the life of the device. While it is under warranty, it is better to carry out preventive work at a service center. This will eliminate conflicts with the manufacturer if problems arise with the tool.