Comparison DeWALT DCD701D2 vs DeWALT DCD791D2

The useful power of the tool is the maximum power that it can deliver to the working nozzle. This power is always less than the power consumed (see below), since part of the electricity inevitably goes to heat and friction in the tool mechanisms. In addition, this parameter is not given for every model, often information in the characteristics is limited to power consumption. Nevertheless, the actual capabilities of the tool directly depend on the net power: the higher it is, the greater the speed and/or torque this model is able to develop, the easier it is for it to cope with tasks that require high efforts. So, to compare different devices with each other, it is best to use this parameter (of course, you can only compare models of the same type or similar in type).

Also note that high working power is not always an advantage: it accordingly affects the dimensions, weight and price of the tool, while in fact high speeds and efforts are not always necessary. Detailed recommendations on the optimal values for different tools and different types of work can be found in special sources.

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.

Torque is the maximum force with which this model is capable of turning the working nozzle.

Higher torque gives more options, it allows you to cope with complex tasks such as drilling in hard materials, unscrewing stuck screws and nuts, etc. On the other hand, a lot of force requires corresponding power — and this, in turn, affects the dimensions , weight and cost of the tool itself, and also puts forward increased power requirements (mains power, battery capacity or pressure / compressor performance). And for some tasks, excessive torque is basically unacceptable, so for maximum versatility, it is desirable to have torque control — and this affects the cost even more. And the more steps, the more optimally you can configure the tool to perform a particular type of work. So the general rule is this: when choosing, it is worth considering the specifics of the planned work, and not chasing the greatest working effort.

Detailed recommendations on choosing the optimal torque for different types of tools (see "Device") can be found in special sources. Here we note that it is of key importance primarily for screwdrivers, although it is also given for other types of tools. At the same time, in the “weakest” models, the maximum working force does not exceed 15 Nm, in the most powerful ones it is more than 150 Nm.

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.

The nominal diameter of the chuck supplied with the tool.

This size is indicated by the maximum diameter of the drill (or bit shank) that can be installed in the fixture. There are several standard sizes; the most popular nowadays are the 10 mm cartridge and the 13 mm cartridge ; drills with a 16 mm chuck are noticeably less common, as well as miniature mounts less than 10 mm(usually 8 mm or 6 mm).

The larger the drill, the more power is required for its efficient use; accordingly, larger cartridges are characteristic of heavier and more powerful tools. At the same time, it is quite possible to install a smaller cartridge on the drill, if the possibility of replacement is technically provided for at all. But the possibility of working with larger fasteners (and drills for them) should be clarified separately: not every tool has enough power for this.

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.

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.

The name of the battery platform supported by the device. A single battery platform is used to combine various power tools of the same brand into one line (screwdriver, grinder, circular saw, etc.). Devices on the same platform use interchangeable batteries and chargers. Thanks to this, for example, there is no need to select a battery for each individual model of a power tool, because one purchased as a spare battery can be used in various power tools, depending on the situation or as needed. Batteries of the same platform basically differ from each other except perhaps in capacity.

Rated battery voltage for which the cordless tool is designed (see "Power Source").

Manufacturers select the battery voltage taking into account the performance characteristics of the tool and the power supply required to achieve these characteristics. In fact, this means that most often this parameter can be ignored at all when choosing. The only exceptions are some specific situations — for example, if the "household" already has a battery of the same company and you want to evaluate its compatibility with the selected model, if the selected tool is supplied without a battery and you want to immediately order a power source for it, or for accurate comparison of batteries by capacity (see below for more details). But after the purchase, the voltage data can also be useful for finding chargers in addition to or to replace the "native" charger.

As for specific values, in many models the voltage does not exceed 10 V — this is often quite enough. However, much more popular options are 11 to 15 V and 16 to 20 V. There are also higher voltages, but much less frequently.