Impact energy
The energy transmitted by the perforator to the material being processed upon impact; the higher this indicator, the stronger and more powerful each individual blow.
First of all, we recall that the energy of impacts is directly related to their frequency: an increase in frequency leads to a decrease in energy. Therefore, for models where the number of strokes can be adjusted, this paragraph usually gives the maximum energy achieved at the minimum speed of operation.
In general, higher impact energy improves efficiency when working with hard, stubborn materials, but requires more motor power (especially if it has to be combined with a high frequency). Therefore, it is worth choosing according to this parameter, taking into account specific tasks. So, for occasional use in everyday life, an energy of 2 J or less is enough, for home repair work of medium intensity, at least 3 J is desirable; a power of
4 J or more is already considered high; and in some industrial-grade perforators, this figure can reach 30 J.
Reverse
The reverse allows you to switch the direction of rotation of the nozzle. It also indicates the type of switch responsible for the reverse. The options might be:
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Crawler. A switch in the form of a slider with two working positions (plus a neutral one between them, at which the tool does not turn on at all). Usually, it is able to move in the direction "back and forth" — this option is considered the most practical. The sliders are quite simple and at the same time convenient and visual.
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Flag. A switch in the form of a flag, usually installed above the start button and thrown to the right and left. One of the advantages of the checkbox is that it is right at your fingertips and can be switched almost “without unnecessary movements” (which is not always available for the slider).
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Brush (on the engine). The brush reverse differs from the two options described above not so much in the design of the switch as in the principle of operation: it changes the direction of rotation not by controlling the current on the motor windings, but by a special movable brush holder for this motor. This allows you to develop maximum power in any direction of rotation (which is not always available with electronic adjustment), and also reduces wear on individual engine components. The disadvantages of this option are complexity an
...d high cost.
— Gearbox. A rather specific option: switching the direction due to the settings of the gearbox (the mechanism that transmits rotation from the engine to the cartridge). Here you can draw an analogy with turning on the reverse gear in a car: turning on the reverse affects only the cartridge with the tooling, the tool motor continues to rotate in the same direction. This allows you to use the full power of the motor in any direction of rotation; and the absence of unnecessary switches has a positive effect on the reliability of the electrical components of the tool. On the other hand, gears with a reverse function are quite complex and expensive, and therefore they are rarely found in individual professional-grade rotary hammers. Wood drilling max. ⌀
The maximum diameter of a tool that can be used with a rotary hammer when drilling in wood (and, accordingly, the maximum diameter of the resulting hole). With a large drilling diameter, the loads on the device increase, and some models may simply not be designed for them (despite the technical possibility of installing tools of the appropriate diameter), as a result, it is not worth exceeding the maximum specified diameter, because. this may damage the instrument.
Concrete drilling max. ⌀
The maximum tool diameter that can be used with a rotary hammer when drilling in concrete. See "Maximum drilling diameter in wood" for details.
Power cord length
Power cord length for mains powered drills (see above). The
longer the cord, the farther from the outlet you can use the unit and the less it depends on the location of the outlets.
Weight
The weight of a fully assembled rotary hammer (in the case of battery power, with a standard battery installed). Unlike many other types of equipment, in the case of rotary hammers, light weight is far from always an advantage. So, heavy models are better suited for professional use — they are less prone to vibrations and, usually, are stronger, which is important when working with difficult-to-cut materials for a long time. But for small, simple works of short duration, a lot of weight is not required, and in this case,
light models are useful, which do not require significant effort to hold on weight.
