Power consumption
The total power consumed by a mains-powered electric tool (see "Power Source"). It is considered the main criterion for assessing the overall capabilities of a particular model: more power allows you to achieve more speed and/or torque. However a more correct parameter for such an assessment is useful (working) power, but it is far from always indicated, and tools of the same type with similar power consumption usually do not differ much in terms of working power. In addition, data on power consumption also allows you to estimate the load on the power grid or other power source; in some cases this is unnecessary.
As for specific figures, for different types of tools, the characteristic power values will be different. For example,
from 750 to 1000 W is considered a very solid indicator for a screwdriver, while for classic drills this is an average value, among such devices there are options even for
1.5 kW or more. Detailed recommendations on choosing a tool for this parameter can be found in special sources. We only note that it does not always make sense to chase the maximum values high power noticeably affects the dimensions, weight and price of the unit, despite the fact that it is far from always required.
Rotation speed
The speed of rotation of the working nozzle provided by the tool.
If a single number is indicated in this paragraph (for example, 1800), it can be either a standard, constant, or maximum rotation speed. This refers to the maximum speed if the tool has more than one speed (see "Number of speeds") and/or a speed controller (see "Functions"). In turn, two or three numbers through an oblique line (for example, 1100/2300/3400) are indicated only for models that have the corresponding number of individual speeds. Each of these numbers indicates the standard (and in the presence of a speed controller — the maximum) number of revolutions at one of the speeds.
Anyway, when choosing a tool by the number of revolutions, it is worth considering both its general type (see "Device") and the specifics of the intended work. Detailed recommendations on this matter are quite extensive, it makes no sense to give them in full here — it is better to turn to special sources. We note only a few general points. So,
high -speed drills nowadays are considered to be drills capable of delivering more than 3000 rpm. In general, high speed contributes to productivity, but there is also a downside: increasing the speed (for the same power) reduces torque — accordingly, the efficiency of working with stubborn materials and large diameter nozzles decreases. Therefore, it makes sense to specifically look for a "high-speed" tool only if speed is of key impor
...tance; it doesn’t hurt to make sure that the model you choose can provide the required efficiency and torque.Max. beats
The number of beats per minute provided by a tool that supports the corresponding mode.
For more information about this mode, see "Functions", here we note that it can be provided both in drills and in screwdrivers and wrenches (see "Device"), and the meaning of the impact mode in these varieties is somewhat different. Therefore, the speeds differ: many drills are capable of delivering about 48,000 beats / min, or even 64,000 beats / min, while in screwdrivers and wrenches, 3200 beats / min are considered “classics of the genre”, and values above 3500 beats / min are practically do not meet.
The general meaning of this indicator is also directly related to the type. So, among drills, the difference in chiseling speed can be quite large. With these tools, more strokes improve overall productivity and efficiency, while fewer strokes improve accuracy and reduce the risk of damaging delicate materials. In screwdrivers and nutrunners, high speed also contributes to overall efficiency, but for most of these tools, the differences in this indicator are not significant enough to be noticeable in practice.
Reducer
The type of gearbox provided in the design of the tool.
A gearbox can be simply described as a mechanism that transmits rotation from an electric motor to a chuck. In this case, usually, the rotation speed decreases, due to which the torque increases. Different types of gearboxes differ just in the number of speeds that can be obtained at the output. The simplest variety of such mechanisms is single-speed, they are as simple as possible, compact and reliable. At the same time, in a tool with a 1-speed gearbox, speed control may well be provided — due to electronic circuits that allow you to adjust the engine speed. On the other hand, reducing the actual speed by means of electronic control does not lead to an increase, but to a decrease in torque.
More advanced are multi-speed gearboxes, usually having 2 to 4 speeds. Such mechanisms are analogous to a gearbox in a car: the speed in them is regulated by changing the gear ratio, so that a decrease in speed leads to an increase in torque, and vice versa. Such an adjustment is considered more practical than the electronic one described above; the downside is the complexity and high cost of multi-speed gearboxes.
Number of speeds
The number of speeds provided in the design of the tool.
First of all, let's clarify that "speed" in this case means high-speed mode. The number of revolutions at each "speed" can be either fixed or adjustable (if there is an appropriate regulator — see "Functions"). Thus, the presence of several speeds can have different meanings. In some models, changing the speed mode is the only option for adjusting the speed; in others (if there is a separate speed controller), changing the mode sets only the maximum speed of rotation of the nozzle, and its actual speed is smoothly changed by the controller (which may also have its own, additional speed limiter).
As for the specific number of speed modes, in many models it
is only one. Accordingly, the revolutions in such a tool either do not change at all, or are controlled only by the mentioned regulator; this is often sufficient for simple tasks. However,
2-speed tools are also very widespread — this design provides additional tuning options and at the same time remains relatively simple and inexpensive. And in fairly advanced models, you can find
three, or even
four or more speed modes; in some cases, this number reaches 8 or even more, which allows you to use speed switching as a full-fledged speed controller.
When choosing according to this characteristic, it should be
...taken into account that, other things being equal, a larger number of speeds gives more features for setting operating parameters, but complicates the design and increases its cost.Weight
The total weight of the tool is usually the device itself, without attachments. For battery models (see "Power Source"), usually, the weight is indicated with a standard battery installed; for battery-powered models, the weight can be given both with and without batteries, but in this case this point is not particularly important.
Other things being equal, less weight simplifies work, increases accuracy of movement and allows you to use the tool for longer without tiring. However, note that high power and productivity inevitably increase the mass of the tool; and various tricks to reduce weight increase the price and can reduce reliability. In addition, in some cases, a massive design is more preferable. First of all, this applies to work with a large load — for example, drilling holes of large diameter, or making recesses with impact: a heavy tool is more stable, it is less prone to jerks and shifts due to uneven material, vibration of mechanisms, etc.
It is also worth noting that specific weight values are directly related to the type of tool (see "Device"). Screwdrivers are the lightest — in most of them this figure
does not exceed 500 g. Screwdrivers and drill drivers are more "heavy": their average weight is
1.1 – 1.5 kg, although there are many lighter (
0.6 – 1 kg) and heavier (
1.6 – 2 kg or more ) models. And clas
...sic drills and wrenches have the greatest weight: such a tool must be quite powerful, so for them 1.6 – 2 kg is an average, 2.1 – 2.5 kg is above average, and many units weigh more than 2, 5 kg.Wood drilling max. ⌀
The largest diameter of holes that the tool can make when drilling with a conventional drill in wood.
The larger the hole diameter, the higher the resistance of the material, the more power the tool must provide and the higher the load on it. Therefore, the maximum allowable drilling diameter must not be exceeded, even if the chuck allows you to install a thicker drill bit — this can lead to tool breakage and even injury to others.
It is worth noting that some types of wood can have a fairly high density, and for them the actual allowable drill diameter will be, accordingly, less than the claimed one. However, this is true mainly for exotic breeds, which are extremely rare in our area.
Metal drilling max. ⌀
The largest diameter of holes that the tool is capable of making when drilling with a conventional drill in metal.
The larger the hole diameter, the higher the resistance of the material, the more power the tool must provide and the higher the load on it. Therefore, the maximum allowable drilling diameter must not be exceeded, even if the chuck allows you to install a thicker drill bit — this can lead to tool breakage and even injury to others.
Also note that the drilling diameter for metal is usually indicated based on medium hard steel and other similar materials. For metals and alloys that have a significantly higher hardness and density, the allowable drill thickness will be less; however, such situations occur infrequently, and if you wish, you can find out about the features of working with various alloys x in special sources.
Concrete drilling max. ⌀
The largest diameter of the holes that the tool is capable of making when drilling with a conventional drill in concrete. It is worth considering that in this case we are not talking about reinforced concrete — this material requires special methods of influence (ideally, the use of diamond crowns).
The larger the hole diameter, the higher the resistance of the material, the more power the tool must provide and the higher the load on it. Therefore, the maximum allowable drilling diameter must not be exceeded, even if the chuck allows you to install a thicker drill bit — this can lead to tool breakage and even injury to others.
