Comparison Grand AG-21UBL Pro vs Grand DA-21BL Pro

General type of instrument.

Nowadays, several other types of hand tools are also combined into one category with traditional drills, with a similar design and principle of operation: drill drivers, classic screwdrivers, wrenches and electric screwdrivers. Here is a detailed description of each of these varieties:

— Drill. Traditional drills are power tools for drilling holes in various materials. By specialization and “weight category”, such tools range from miniature cordless models to heavy professional diamond drilling units (see “Intended Use”). Anyway, drills are equipped with chucks for installing drills, as well as engines designed for significant resistance during operation. Also note that many of these units have an impact mode, but the drill is still not able to replace a full-fledged rotary hammer (for more details, see "Functions").

— Screwdriver. In fact, it is an electric (or pneumatic) analogue of a manual screwdriver. It is used primarily for tightening and loosening screws, screws and other similar fasteners using bits — interchangeable nozzles, the shape of which imitates various screwdriver tips (straight, cross-shaped, etc.). Accordingly, the standard type of retainer for the nozzle in such a tool is for a bit (see "Chuck Type"). Screwdrivers differ from electric...screwdrivers (see below) in higher power, better suitability for long-term work and high loads, as well as larger dimensions and rather significant (in comparison, of course) weight.

— Drill driver. Tools (mainly cordless, see "Power source") that combine the functionality of a drill and a screwdriver. See above for more on both, and these "hybrid" devices are extremely popular these days due to their versatility. Switching between drilling and twisting modes in them is carried out by changing the cartridge, and also, in most models, by adjusting the torque (see below). At the same time, it should be noted that compared to traditional drills, the efficiency of such units when drilling is rather low, they are not intended for high loads, hard materials and large drilling diameters. This is due to the fact that in order to achieve high power, it would be necessary to increase the dimensions and weight, which would significantly complicate the use in the format of a screwdriver.

— Screwdriver. A kind of electric and pneumatic analogues of socket wrenches: tools designed to work with nuts and other similar fasteners (for example, bolts with heads without a slot). Nutrunners are in many ways similar to the screwdrivers described above and differ mainly in the type of cartridge — usually it is a square for sockets of different sizes.

— Screwdriver. An electrical analogue of a conventional manual screwdriver (pneumatic drive is not used in such devices for a number of reasons). Some of these models have a straight body shape (see "Construction") and are very similar in appearance to hand tools; others resemble smaller and lighter screwdrivers (see below). Anyway, electric screwdrivers are intended mainly for work where accuracy and accuracy are more important than high efforts (or where these efforts are simply not required). Thus, the low power of such devices is not so much a disadvantage as a feature. In addition, this feature allows you to use battery power without much difficulty, making the tool as autonomous as possible; in fact, electric screwdrivers with mains operation nowadays are almost never found. And the small size and weight, in turn, contribute to the mentioned accuracy and accuracy.

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.

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.

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 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.

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.

Two points depend on the type of cartridge: the types of working tools (drills, screwdrivers, etc.) with which this or that model is compatible, and the method of installing / removing them.

— Key. As the name implies, you will need a special key to work with such a cartridge. The mount itself is usually designed for tools with round shanks (mostly drills) and includes three cams that, when clamped, converge towards the centre, clamping the tool installed in the chuck on the axis of rotation. The main disadvantage of this type of cartridge is the need to use a key: it can be lost and the mount becomes useless. In addition, installing and removing a working tool can be quite a long process. However, the keyed chuck is considered somewhat more reliable than the keyless chuck and more suitable for heavy work.

— Quick release. Similar to the keyed chuck described above, this type of chuck is designed primarily for drills with round shanks. Its main difference is the absence of a key — you can fix or remove the drill with the help of a hand, without any additional tools. Such chucks are slightly less suitable for work with high loads (for example, in hard materials and/or with large diameter drills), but otherwise they do not lose in any way with the key, and in terms of ease of use they are significantly superior.

— Under the beat. Bits are working tool...s used in screwdrivers and screwdrivers (see "Device"). The working side of the bit can have a flat, cruciform or other shape (star, trihedron, etc.), but the shank with which it is fixed in the cartridge is standardly made hexagonal. Accordingly, the bit chuck has a recess for such a shank. Fixation can be carried out mechanically, in the form of a simple latch, or with a magnet; in both cases, the mount is secure enough for safe operation, and the tool can be removed without much effort.

— Morse taper. A cartridge for one of the varieties of the tool cone — the so-called Morse cone. As the name implies, this mount involves a conical shank and a corresponding hole for it (often with an additional groove for the protrusion on the shank — for secure fixation and prevention of rotation). This option is found mainly in drills (see "Device"). Note that the Morse cone is available in several sizes that are incompatible with each other.

— Square. The type of chuck used in impact wrenches. Unlike all other varieties, the working tool for the “square” is not installed inside the cartridge, but is put on it from the outside. Squares can have several standard sizes, but these sizes are the same for both electric and hand tools. In fact, this means that nozzles from manual wrenches can also be used in electric models if the landing size is the same (and if not the same, you can use an adapter, although this is less convenient).

— None (threaded spindle). The absence of a cartridge as such: a thread located directly on the spindle is used to fasten the working nozzles. Almost all models with this feature are powerful professional tools designed for diamond drilling (see "Intended use") — for a number of reasons, it is the threaded spindle that is considered the best way to attach nozzles for such drilling. Note that the thread on the nozzle can be both external and internal; most spindles are compatible with both varieties, but there are exceptions. So this nuance needs to be specified separately.

Note that in some models two types of cartridges can be combined — for example, for a bit and quick-clamping. Usually, for this, the kit provides two different cartridges that can be changed as needed, but there are other options — for example, a spindle into which you can insert both a bit and a drill chuck (key or keyless). Anyway, this makes the tool more versatile and allows you to work with numerous working attachments.

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 size of the mount type "square", provided in the design of the tool.

For the mount itself, see "Chuck type", here we just recall that squares are mainly used in wrenches for installing socket heads. At the same time, for larger nozzles, usually, larger mounts are also used. And the sizes of squares are traditionally indicated by fractional parts of an inch. The most popular option is the 1/2" square, it is the most versatile. Both larger sizes ( 3/4" square and 1" square) and smaller ones ( 3/8" square and 1/4" square) are somewhat less common. ).

Note that there are adapters that allow you to install nozzles of a “non-native” size on a square. However, the possibility of using larger nozzles than regular ones should be clarified separately: the tool may not have enough power for this. In addition, single wrench models are available that initially provide a replacement square and are equipped with interchangeable fasteners — usually 1/4" and 3/8", but other options are also possible.