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.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.
Reverse
Type of
reverse provided in the design of the tool.
The reverse allows you to switch the direction of rotation of the nozzle; see "Functions" for details. It also indicates the type of switch responsible for this function. The varieties of such switches nowadays are very diverse:
slider,
flag,
brush on the engine,
on the start button,
gyroscopic,
on the keyboard toggle switch, and also combined with
a flow switch or
ratchet mechanism. Here is a detailed description of each of these varieties:
— Crawler. Switch in the form of a slider with two opposite positions. Usually, it moves in the direction "back and forth" relative to the tool chuck — this format is considered the most practical. The sliders are quite simple and at the same time convenient and visual, especially when used in screwdrivers and wrenches: by moving forward (away from you), the direction of rotation is set to twisting, by moving backward (toward yourself), respectively, to unscrewing. However, such devices are widely used in other types of instruments (see "Device") and are generally the most popular option nowadays.
— Combined with the flow switch. The most popular type of reve
...rse in pneumatic tools (see "Power Source"); not found in other models. The flow switch itself is actually a speed controller, most often in the form of a distinctive rotary knob or lever. And if this regulator is combined with a reverse, this means that it can deviate from the neutral position in two directions, and the direction of rotation will depend on which direction the flow switch is shifted.
— 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 a checkbox is that it is right at your fingertips and can be toggled with almost no unnecessary movement (which is not always available for a slider). On the other hand, this option is mainly suitable for drills, and in screwdrivers and wrenches, the checkbox is not as intuitive as the same slider. And in general, this type of reverse for a number of reasons is much less common.
— Brush (on the engine). Reverse switch installed directly in the tool motor and based on the use of a special movable brush holder. By changing the position of the brushes in the motor with the help of such a mechanism, it is possible to change the direction of its rotation. One of the key advantages of this method is that it allows you to achieve maximum power in any direction of rotation without any special tricks. In addition, such an adjustment has a positive effect on the engine resource. On the other hand, brush switches are quite complex and expensive, and therefore are installed mainly in a powerful professional tool.
— On the start button. Reverse switch combined with start button. Such a combination button is usually made in the form of a "rocker", and the direction of rotation depends on which side of the rocker the user pressed; pressing the same button immediately starts the engine. This design allows you to easily and quickly change the direction of rotation — for this you do not need to be distracted by individual switches, just move your finger slightly and press the other half of the start button. This is especially convenient for screw and wrench drivers, as well as screwdrivers; in fact, most of the models with this type of reverse belong to these types.
— On a keyboard switch. The control method, in many respects similar to the reverse on the start button described above, also uses a rocker switch. The key difference is that in this case the direction switch is made separately from the start button — that is, the user must first select the direction of movement, and then press "start". This option does not have any particular drawbacks, but it also does not differ in convenience, and therefore it is extremely rare.
— Gyroscopic. A rather rare and specific type of reverse, found exclusively in screwdrivers (see "Type"). In fact, there are no external switches in such a tool — instead, a built-in gyroscope is used to track body rotations. Accordingly, to select the direction of movement, you need to rather sharply turn the tool around the longitudinal axis in the appropriate direction and smoothly return it to its original position (speed can be adjusted in the same way — for example, the farther the turn, the higher the speed will be). This control method is very simple and intuitive, but it is rather complicated in technical implementation and requires increased accuracy in handling the tool. That is why gyroscopic reverse is extremely rare nowadays.
— Combined with a ratchet mechanism. Another rather rare option, found exclusively in wrenches — mostly pneumatic, less often battery-powered (see "Power"). The ratchet mechanism, we recall, is responsible for ensuring that the working part of the tool rotates in only one direction. And the reverse is controlled through a mechanical switch, which is directly connected to this mechanism and changes its settings, setting one or another direction of rotation.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.Features
—
Impact mode. Ability to work in the so-called shock mode. Usually, this mode is turned on and off at the request of the user, and its meaning and features may be different, depending on the type of instrument (see "Device"). So, in drills, strikes are carried out along the axis of the drill, and their frequency is usually several thousand per minute — this has a positive effect on productivity and allows you to more effectively cope with hard, dense materials (although such a drill can not be replaced anyway). In turn, in screwdrivers and wrenches, it would be more correct to call the impact mode pulsed: in this format of operation, the tool nozzle does not rotate uniformly, but in separate jerks, usually at a frequency of about 3K per minute. It also improves work efficiency, which is especially useful when driving self-tapping screws into dense material and unscrewing old, “stuck” fasteners.
—
Engine brake. A device that additionally slows down the engine when the tool is turned off. The engine itself (and, accordingly, the working nozzle) after turning off can rotate for quite a long time by inertia; the brake stops this rotation almost immediately, so you do not have to keep the tool on weight for too long.
—
Power button lock. A function that allows you to lock the power button in the pressed position. Usually, it looks like an additional button insta
...lled either on the start key itself or not far from it. This function is very convenient in situations where the tool has to be used for a long time without interruption — for example, when drilling several dozen holes at once: it is easier to fix the start button in the on position than to keep it pressed all the time, additionally straining the finger on the working hand. And the lock is turned off, usually, in the simplest way — for example, by briefly pressing the same start button.
— Speed controller. Possibility to additionally limit the revolutions of the tool. By itself, smooth adjustment is available in almost all modern models: the harder you press the start button, the higher the speed. This allows you to directly "on the go" adjust the mode of operation of the tool to the specifics of the situation. And this regulator allows you to set the maximum speed of rotation, so that even when you press the button “to the stop”, the speed of the working nozzle does not exceed the specified value. This function is indispensable for some jobs that require precision — in particular, when processing delicate materials, for which too high a speed is fraught with damage.
Separately, we emphasize that the presence of a speed controller has nothing to do with the number of speeds (see above). For example, a tool may well have several speed modes, in each of which the speed can be further limited using a regulator.
— Maintain momentum. A feature that allows you to maintain a constant speed of rotation of the nozzle, regardless of the load on it. Without special adjustment, at a constant engine power, the rotational speed inevitably drops with increasing load and increases with a decrease. And the revs control system monitors the resistance on the nozzle and, if necessary, changes the power in such a way that the rotation speed remains constant. This has a positive effect both on the quality of work and on the service life of the nozzles and the entire tool.
— Electronic engine protection. A system that protects the engine from critical overloads — for example, in the event of a jammed drill — and overheating. If the motor load or motor temperature is exceeded, the power to the instrument is automatically turned off to avoid damage to the instrument.
— Brushless motor. The presence of a brushless (brushless) motor in an electric tool. Such motors are noticeably superior to traditional collector motors in terms of efficiency, which can significantly reduce energy consumption without sacrificing power; this is especially important for cordless tools (see "Power Source"), where this feature is predominantly found. In addition, brushless motors are quieter and produce virtually no sparks during operation, making them perfect for working in high fire hazard environments. Their main disadvantages are traditional — the complexity of the design and high price.
— Safety clutch. A device that protects the engine from damage during a sharp increase in load (for example, due to jamming of the drill). In such cases, the safety clutch disconnects the motor shaft from the tool chuck, avoiding overloads. Note that such devices can be both reusable and disposable — the latter are destroyed when triggered, and to continue working, you will need to install a new clutch.
— Backlight. The built-in lamp for illumination of a place of work. This feature can be useful both in the evening/night time, and in hard-to-reach places where there is little penetration of outdoor lighting, as well as in situations where this lighting is too dim. Note that in addition to built-in light sources, modern tools can also be equipped with separate flashlights; for more details about them, see "Complete set".
— Display. Own display, which can display various information about the operation and status of the device — for example, the torque or rotation speed set in the settings, and in battery models, there is also a battery charge indicator. Such a screen provides additional convenience and visibility, however, in general, this is a rather specific function that is extremely rare in modern power tools — for example, a speed or torque indicator can be provided directly on the regulator, and a conventional LED can be provided as a charge indicator, giving signals by blinking or colour change.
— Synchronization with a smartphone. The ability to connect the instrument to a smartphone or other gadget (such as a tablet) via Wi-Fi or Bluetooth. Such a connection is usually used to adjust operating parameters such as speed or torque; doing this through a mobile application is often more convenient than through the controls on the instrument itself. And some models with this function also allow you to set password access: the tool simply will not respond to the start button until the correct password is entered on the control gadget.
— Built-in spirit level. Built-in device to control the angle at which the tool is located to the horizon. As in ordinary levels, the role of the scale in such devices is played by a sealed flask with marks applied to it, containing a brightly coloured liquid and an air spirit. By the position of this spirit relative to the marks, the position of the entire tool is determined — namely, its correspondence to the vertical, horizontal, or pre-set tilt angle (the latter option, however, is almost never found in the built-in levels). At the same time, purely hand tools usually provide a single-axis level that reacts only to deviation from the horizontal forward or backward, and models with the ability to mount on a rack (see below) can also have a circular level that controls compliance with the vertical and determines deviations from it in any direction.
— Revolving mechanism for bits. A mechanism for storing and quickly changing bits used in tools for the corresponding purpose — mainly screwdrivers, but also some screwdrivers (see "Device"). In accordance with the name, the main part of the mechanism is a drum like a revolver, in the compartments of which the bits are stored. The mechanism is located behind the cartridge, and the choice of bits usually occurs as follows: you need to pull back a special casing or handle (if at that moment there was another bit in the cartridge, it will return to the drum), by turning the drum, select the compartment with the desired nozzle, and then move the casing / handle to its original position by pushing the nozzle out of the drum into the chuck. This feature significantly speeds up and simplifies the replacement of nozzles, and also reduces the risk of losing them. On the other hand, the revolving mechanism significantly affects the price and weight of the tool, and its capacity is usually limited to 6 – 8 nozzles. Thus, such a tool is usually also equipped with an adapter for installing bits in the traditional way, from the outside of the cartridge.
— Water cooling(coolant). The tool has a coolant — a liquid cooling system (most often plain water) supplied to the working nozzle using a built-in pump. Such a system performs several functions at once. Firstly, it actually cools the nozzle, preventing damage due to overheating. Secondly, the liquid somewhat reduces friction at the point of contact, further reducing the load on the nozzle and increasing its durability. Thirdly, water absorbs dust generated during drilling, this dust does not fly into the air and does not enter the lungs of people around; and cleaning up after work is much easier. On the other hand, water cooling systems are quite expensive and bulky, and with relatively simple work and low loads, it is quite possible to do without coolant.
— Soft start. A function that provides a smooth spin-up of the tool motor, with relatively little acceleration. This is achieved by limiting the starting current. Without such a limit, the current drawn by the motor at the time of starting can be quite high, causing the motor to start very abruptly, which increases the risk of letting go of the tool. In addition, current surges can lead to overloads in the network used for power. Soft start allows you to eliminate these phenomena to some extent. Note that it is used only in mains-powered models — the motors in cordless tools are not so powerful that they have the actual “troubles” described for them.In box
- Corner nozzle. A nozzle that allows you to rotate the axis of rotation of the cartridge by 90 ° relative to its original position. Such a device is indispensable for making holes, as well as twisting and unscrewing fasteners in some hard-to-reach places (for example, in narrow grooves or a profile).
- Eccentric nozzle. Replaceable nozzle designed to shift the axis of rotation of the cartridge slightly away from its original position. In this case, the direction of the axis remains the same. Like the corner nozzle, such a device is intended mainly for working in certain hard-to-reach places (in particular, near walls and edges of workpieces).
-
Additional handle. A modern tool, even a relatively low-power one, can be quite massive, and for maximum accuracy and reliability it may be necessary to hold it with two hands at once. Using an additional handle for this is more convenient and safer than looking for a place to grip on the body. The handles themselves are usually mounted near the cartridge perpendicular to the axis of rotation and may have different design features.
-
Depth stop. A device that allows you to limit the depth of drilling. The most popular version of such a limiter is a rod in a special mount, installed parallel to the drill. Before starting work, this rod is shifted so that when the desired depth is reached, its end rests on the surface of the material,
...preventing the drill from moving further.
- Store nozzle. It looks like a kind of store or disk, into which a tape with self-tapping screws is “charged”; and a special block is installed in front of the cartridge, designed to supply self-tapping screws. This design allows you to tighten the screws as quickly as possible and without unnecessary movements: just load the tape from the magazine into the feed unit, start the engine and alternately press the working part of the tool to the desired points on the material.
- Lantern. A classic flashlight for illumination in low light conditions, in contrast to the built-in illumination system, is a separate device. Such a separate device is not very convenient to hold in your hand during work - in such cases you can’t take the tool with both hands, and this creates problems in some situations. On the other hand, often the situation allows you to put or hang a lantern without taking up your hands; and sometimes in this way you can even organize the lighting more successfully than using the built-in backlight. In addition, the flashlight can be used independently.
- Case (bag) included. The presence of a case or bag in the delivery set of the drill. Cases are usually called hard suitcases; bags, unlike cases, are soft, which allows them to be packed more tightly together with other things, but reduces the degree of protection. In any case, this feature makes the tool more convenient to store and carry: the complete bag or case is optimally suited for this model, in addition, they can hold drills, spare batteries and other additional accessories.
- Rack. Mostly professional drills for diamond drilling are completed with racks(see "Purpose"). This design is a stand (base) with a guide rail fixed on it, along which the tool can move using a special mechanism. According to the fastening of the rail, the racks are divided into two types:
- Non-inclined stand. A structure with a rigidly fixed rail, which is usually located vertically, perpendicular to the base; accordingly, the axis of rotation of the installed tool also remains always vertical. Such racks have more limited capabilities than inclined ones. On the other hand, they are simpler, cheaper and more reliable (there is no movable mount in the design that can become loose); and for most work, the vertical position of the tool is fine.
- Tilt stand. Stands in which the rail is fixed on a swivel mount and can deviate from the vertical at a certain angle. Accordingly, such a device allows you to direct the crown not only vertically, but also at an angle; this can be important for some non-standard tasks. On the other hand, a movable structure is more complex, expensive and less durable than a fixed one; therefore, it is worth paying attention to this option if the possibility of inclined drilling is fundamental for you.
- A set of drills. The presence of drills in the kit eliminates the need to purchase them separately and allows you to use a drill (or other tool with drill functions) right out of the box. True, the specific assortment of drills can be different - besides, it is often an entry-level set of 5 to 7 devices for the simplest tasks like drilling wood. However, even such a set will be useful if the tool is purchased for domestic use or simple work that does not require specialized nozzles. We also note that such equipment is especially convenient when buying a “first tool for a beginner”, when there are no drills on the farm yet and one way or another you will have to buy them.
- A set of bits. Bits, we recall, are nozzles in the form of screwdriver heads, which are also used in screwdrivers. As in the case of drills, the presence of such nozzles in the kit eliminates the need to purchase them separately and makes it possible to use the tool immediately after purchase. The specific set of bits is worth specifying further, but most often it includes at least flat and cross bits in a fairly large variety of sizes. And in general, such sets are quite extensive - even in relatively inexpensive tools, the number of complete bits can be measured in tens.
- Equipment. The term "equipment" means at least several types of working nozzles, and sometimes additional accessories. For example, if such equipment is indicated for a drill-driver, then this model is almost guaranteed to be equipped with both drills and bits (and possibly more specific accessories). A specific set of equipment should be specified separately.
- Extension. The purpose of such an accessory is clear from the name: it allows you to increase the working length of the tool. In other words, when you install an extension bat or other equipment, it is further from the body; the extension itself is made quite thin. This accessory is used mainly in models with the functions of a screwdriver or wrench: it allows you to reach deep-seated fasteners that are inaccessible in the usual configuration. And in many models, the extension cord is also made flexible, which further expands its capabilities.
- Magnetizer. Device for magnetizing bolts, screws and other similar fasteners. Found in individual screwdrivers; the working tooling of such tools is also made of magnetic material, due to which the magnetized fastener effectively “sticks” to the tooling and does not need to be supported separately.
- Case insert. Interchangeable insert (or several inserts) to adjust the complete case to the specific situation. For example, a regular insert can only have space for a tool and a charger, and a replacement one can also accommodate a second spare battery. Specific features should be specified separately.
- Charger(charger). A device for charging the batteries used in the tool with the appropriate power supply. For models supplied with such a device, the charger model may be additionally specified in the characteristics. This information can be useful not only for finding a spare or replacement charger, but also in case the household has other cordless tools and / or batteries for them. The fact is that many manufacturers nowadays use universal batteries that are compatible with a whole set of tools from the same brand; so, for example, a complete charger for a drill may be quite suitable for a cordless grinder from the same manufacturer.
On the other hand, a lot of modern cordless tools come without a charger at all. This option will be optimal, first of all, if a compatible memory is already available, and there is simply no need to overpay for a second device. In addition, the lack of a charger will be appreciated by those who want to choose this accessory separately, without relying on the manufacturer's decision.
Note that the above list is not complete - modern tools can be supplied with other additional items, including very unexpected and original ones - like a fitness tracker or even a radio-controlled car.Battery capacity
The capacity of the battery that comes with the corresponding tool (see “Power source”). The most limited capacity values in modern power tools
do not even reach 1 Ah ; such batteries are found mainly among
electric screwdrivers(see “Device”). And in powerful professional models there are batteries with
3 - 4 Ah or even
more.
In theory, the higher the capacity, the longer the tool can work on a single battery charge. However, in practice, everything is far from so simple. Firstly, ampere-hours are a fairly specific unit; its features are such that only batteries with the same voltage can be directly compared by the number of ampere-hours. If there is a difference in voltage, you need to convert the capacity into watt hours and use them for comparison. Secondly, the actual autonomy of the tool depends not only on the properties of the battery, but also on power consumption and other performance characteristics. Thus, it is possible to compare different models in terms of battery capacity only with the same supply voltage and similar capabilities.
Charging connector
The presence in the cordless tool (see "Power supply") of a standard connector for charging.
This feature is found mainly in low-power models with non-removable batteries (see "Complete battery"). Such a tool is usually equipped with an adapter cable from the charging connector to a standard USB. This allows you to use not only a standard device for such a battery, but also many other accessories — chargers for smartphones, tablets and other gadgets, universal adapters for sockets and car cigarette lighters, USB connectors on computers, laptops and other equipment, portable Power bank batteries, etc. P. Specifically, the connectors in power tools can be as follows:
—
microUSB. One of the miniature versions of the USB connector, still popular in portable gadgets, despite the emergence of a more advanced USB-C. It has relatively modest capabilities (in particular, it is inferior to USB-C in terms of the maximum possible charging power), but this moment is rarely critical. At the same time, there are a great many cables and chargers for microUSB.
—
USB-C. Relatively new type of USB connector. Like microUSB, it has a miniature size, but it has a more convenient two-way design and advanced features. In the case of a power tool, the main advantage of USB-C is the ability to provide fairly high charging power and reduce procedure time (although the specific power supported may vary — de
...pending on both the charger and the tool itself). There are slightly fewer accessories for USB-C than for microUSB, but usually there are no problems finding them; and with the further development of this standard, the situation may change dramatically.