Screwdriver is the correct name. Requirements for portable power tools. Buying low-capacity batteries for long-term use

Please review the portable power tool requirements before purchasing. They are regulated state standards and technical specifications for electrical safety.

You can get acquainted with them, for example, on the Energokontakt website.

First of all, let's list what applies to a portable power tool. These are electric soldering irons, electric drills, screwdrivers, impact wrenches, furrowers, electric hammer drills, grinding machines, portable electric heating devices for technological needs, step-down transformers for powering power tools, local lighting fixtures, portable electrical panels and other current collectors.

Classes

Portable power tools are divided into classes.

Class zero includes power tools with working insulation, without grounding elements, which do not belong to the second and third classes.

A first class power tool has working insulation and an element for grounding. Its wire leading to the power source must be equipped with a grounding conductor and a plug with a grounding contact.

Power tools of the second class have double or reinforced insulation, but there are no grounding elements.

A third class power tool is designed to operate at ultra-low voltage (no more than 42 volts) and does not have any electrical circuits operating at a different voltage.

Voltage for instruments of the first and second classes - no more than 220 volts at DC, 380 volts - at alternating.

Room

The tool voltage should not exceed 380/220 volts when working in non-hazardous areas and 36 volts in other areas or outside.

In rooms with increased danger there is one of the following factors: high dampness (relative humidity more than 75%); temperature above 35ºС; conductive floors; conductive dust; the possibility of simultaneous contact with the metal structures of the building connected to the ground, or with technological equipment - on the one hand, and with the metal casing of electrical equipment - on the other.

Particularly dangerous areas include rooms with relative humidity of about 100%; with a chemically active or organic medium; containing two or more high-risk factors.

Main general requirement for individual users - perform work from the network only if the power tool has a permanent flexible cord with a plug. The cord must be protected from damage and contact with damp, hot and oily surfaces.

When the plug is turned on, its design must ensure early closure of the ground contact, and when turned off, subsequent opening. It also needs to be protected from moisture. The power tool must be quickly connected to the network and disconnected from it (but not spontaneously).

Malfunctions

And the super important thing! If any, even minor, malfunction is detected, work must be stopped immediately!

Typical malfunctions of portable power tools include: damage to the plug or cord; unclear operation of the switch; leakage of lubricant from the gearbox; sparking of the commutator brushes with the appearance of a circular fire on the surface; the appearance of smoke, the smell of burnt insulation, noise, knocking or vibration.

To provide safe work It is very important that the body of the power tool is grounded.

Human

Only specially trained persons may operate power tools. safe handling with him. If there is a malfunction, you cannot repair the instrument or its cord and plug yourself - such repairs are usually not of high quality.

When working with power tools, depending on their type, you need to use personal protective equipment, which includes a cotton suit or robe, dielectric gloves, galoshes, rubber mats, etc. In particular hazardous areas application individual funds protection is a must!

Before starting work, it is necessary to carefully inspect the power tool for proper grounding and wire insulation, the absence of exposed live parts and defects. Do not use power tools that have defects!

When finished, remember to unplug the power tool.

December 14, 2016 No comments

A screwdriver has become one of the most popular tools among professionals and home craftsmen today. It will be useful when assembling furniture, installing structures made of plasterboard and plywood, laying roofs made of metal tiles and other work. Let's talk about this tool in more detail.

The screwdriver is manual electric tool for installing or removing fasteners and drilling. A screwdriver is similar in appearance to a drill, and the principle of operation of these tools is also similar: a motor located in the body drives the attachment through a gearbox, which does the work. The difference lies in the energy source (the screwdriver operates on direct current) and the lower speed of rotation transmitted to the attachment. The latter is due to the fact that the screwdriver is initially designed for working with fasteners, in which high speeds are not needed. True, modern screwdrivers differ less and less from drills in this parameter. It is not for nothing that most manufacturers position their tools as multifunctional, calling them drills and screwdrivers.

On the body of the tool there is a start button, a reverse button, a torque setting clutch and a speed switch.

This is also where some screwdrivers have a backlight. The battery is inserted into the housing from the bottom of the handle and securely fastened there with latches. This arrangement contributes to good balance of the instrument.

SCREWDRIVER DEVICE:

• 1 - quick-release chuck;
• 2 - torque setting clutch;
• 3 - speed switch;
• 4 - backlight;
• 5 - power button;
• 6 - reverse button;
• 7 - battery;
• 8 - battery low indicator.

The chuck is designed for attaching attachments (bits and drills) and transmitting rotational motion to them. The most common is a quick-release chuck, which allows you to easily clamp the attachment without using additional tools.

Manufacturers also produce specialized power tools in the line of screwdrivers - for example, today's popular electric screwdrivers, which are small in size and low power. They will do an excellent job with small repairs in an apartment or country house. Impact wrenches, in contrast, have great power; they will help unscrew, say, rusty bolt when removing a wheel from a car.

Torque clutch and speed switch.

By rotating the torque coupling, the desired value is set opposite the marks on the screwdriver body.

Double coupling quick-release chuck. When installing and removing attachments, the couplings are rotated in different directions.
Additional cuff for setting the operating mode of a powerful screwdriver (twisting, drilling, drilling with impact).

An electric screwdriver is great for small repair jobs. An impact wrench has increased power and can become an assistant during construction.

Main characteristics of the tool

When choosing a screwdriver, you first need to pay attention to two parameters - torque and rotation speed. The magnitude of the torque shows how much force is applied to the screw (drill) being turned during operation. For example, the hole will depend on this
What diameter can this screwdriver drill? In household tools, the torque is 10-16 Nm.

For professional models, this figure can reach up to 130 N m. The rotation speed for household tools is in the range of 400-550 rpm. For screwdrivers with a drilling function, it reaches 1,300 rpm. Budget models usually have 1-2 speeds, professional tools most often have three speeds. In addition, the rotation speed is adjusted within one speed by pressing the power button.

The power source for screwdrivers is rechargeable batteries. Nickel-cadmium, lithium-ion and nickel-metal hydride batteries are most often used for these purposes. The output voltage of the batteries can be in the range of 3.5-36 V, but the most applicable range is 9.5-14.4 V. The power of the screwdriver depends on the voltage, although the relationship is not direct.

The most important parameter of a battery for screwdrivers is its capacity, measured by the number of hours during which it is able to provide the declared current. In addition, batteries differ from each other in recharging life, self-discharge rate, and the presence of a memory effect.

Nickel-cadmium (Ni-Cd) batteries

Recharging life is within 1,000 times, high self-discharge, but they have the lowest price among other types of chargers.

Hybrid (Ni-MH) batteries

The resource reaches 1,500 recharging cycles, they have an increased capacity, discharge by 1% per month, the price is average.

Lithium-ion (Li-Ion) batteries

They have a reduced discharge time, there is practically no self-discharge, the resource reaches 3,000 recharging cycles, the price is the highest.

Screwdriver attachments

When working with the tool, attachments are used (bits for working with fasteners and drills). The shank of the nozzles is made in the form of a hexagon, which facilitates its installation. The attachments can be directly clamped in the chuck or installed in an adapter clamped in the chuck. The working part of the bit is something like a screwdriver with a configuration that depends on the type of fastener this attachment is used to work with.

When starting work, you need to select a bit that matches the fastener head. The most commonly used are cross-shaped bits, which come in PH and PZ standards. PH is short for Phillips. PH bits are cross-shaped, universal, they can be used for a variety of fasteners. Sizes - from 0 to A, the most popular is No. 2. The designation PZ is derived from Pozidrive, these are also bits with a cross-shaped working part. In addition to the main large ribs, they have additional smaller diagonal ribs. Thanks to them, the adhesion area with fasteners is even larger than that of PH bits. The sizes of such bits are from 0 to A, the most common are 2 and 3.

For repair household appliances and cars cannot do without T-bits (from Torx Hole), with which you can unscrew and tighten screws with a star hole on the head. Flat, or slotted, bits are suitable for working with fasteners in soft material, with not too high a load. Such bits are marked SL (from Slot).

To work with bolts and nuts, use bits with a working part in the form of a wrench. They can only be used with fairly powerful screwdrivers (wrenches). Bit sizes range from 6 to 13 mm, but we must remember that this is the size of the bit itself, not the bolt or nut.

Attachment sets for screwdrivers often include drill bits with a hex shank. The angle attachment will help when working in hard to reach places. Drill chucks for drills with cylindrical shanks are often used as attachments for screwdrivers.

Additional screwdriver options

Screwdriver options different manufacturers may differ significantly. Their presence increases the convenience of working with the tool, but at the same time they can significantly increase the price of the screwdriver. Therefore, when choosing a tool, you should evaluate the need for a particular option.

• Backlight - one or more LEDs located radially in the front part of the housing. Makes it easier to work in poorly lit places.
• Removable handle for comfortable holding of the tool when drilling. Will help when working with powerful tools, using drills large diameter and hammer drilling.
• A depth gauge is convenient for serial drilling of identical holes.
• The clothespin makes it easier to fix several attachments on the body or the tool itself on the master’s clothing when moving around construction site(convenient when working at heights).

Models from different manufacturers

High-performance compact and powerful cordless drill/driver. Suitable for working with fasteners and drilling. Torque can be controlled by pre-setting the 5-stage torque clutch and drilling position. It has one speed and a quick-release chuck. The delivery set includes a charger, battery pack, and a plastic case.

The cordless drill/driver is designed for drilling holes in various materials, as well as tightening and unscrewing screws during assembly work. Thanks to the ergonomic handle with rubber pad and low weight, the screwdriver will become an indispensable assistant at home. The kit includes a rechargeable flashlight, two rechargeable batteries, a charger, a set of bits, and a plastic case.

This drill/driver belongs to a new generation of cordless power tools with new Li-lon batteries. New design The engine provides economical energy consumption, which significantly increases operating time. The ergonomic handle and body are rubberized as much as possible, which helps to securely hold the tool. The model is equipped with a holster for wearing on a belt. The kit includes an additional battery, charger and flashlight.

The Government of the Russian Federation has expanded the list of technically complex goods, adding a new item to it - electrified tools (hand-held and portable electric machines) (Resolution of the Government of the Russian Federation dated September 17, 2016 No. 929 "). These, for example, include electric drills, electric grinders and electric cutting machines, electric impact wrenches, electric hammers, etc. ().

This change means a special procedure for regulating consumer rights when defects in goods are discovered. In particular, they may refuse to fulfill the purchase and sale agreement and demand a refund of the amount paid or exchange the product for a similar one, but at a different price. general rule within 15 days from the date of sale (clause 1 of article 18 of the Law of the Russian Federation of February 7, 1992 No. 2300-I ""; hereinafter referred to as the law on the protection of consumer rights).

But at the same time, you can perform these actions after 15 days, but only in the established list of cases: if significant drawback goods (for example, which cannot be eliminated) if the deadlines for eliminating defects are violated. This also applies if the product cannot be used every year. warranty period in total more than thirty days due to the repeated elimination of its various deficiencies ().

If the seller, at the conclusion of the contract, stipulated that he was selling goods with defects, are the corresponding requirements of the buyer subject to satisfaction? Find out from the material "The rights of the buyer when defects are discovered in the goods" in "Home Legal Encyclopedia" Internet version of the GARANT system. Get 3 days free!

By the way, technically complex goods currently, including: digital photo and video cameras and lenses for them, refrigerators, computers, game consoles with a digital control unit, mechanical wrist and pocket watches, as well as electronic ones, etc. The same applies to some Vehicle– cars, motorcycles, floating vehicles with an electric motor and others (Resolution of the Government of the Russian Federation of November 10, 2011 No. 924 "").

Many of their readers still remember the times when they had to use only screwdrivers and ordinary wrenches to work with fasteners or threaded connections. It is clear that it is not even necessary to talk about the high productivity of such work. Very often, in order to “drive” a screw into place, it was impossible to do without preliminary, since the efforts of the hand in this case it is not enough for overcoming the resistance of hard wood, not to mention the situation when it was necessary to “pierce” even the thinnest metal sheet. Several hours of such work - and there are inevitable calluses on the hands, and the work has barely progressed.

The situation changed radically with the advent of screwdrivers. At first they were regarded as a kind of instrumental “exoticism”, causing genuine envy. But very soon these useful tools appeared on free sale, “migrated” to the category of publicly available, and today are included in the mandatory “arsenal” of the vast majority of owners of houses or apartments. Those who are just now thinking about purchasing such an invaluable assistant should first understand the question of how to choose a screwdriver, that is, what to look for Special attention when evaluating the wide range of models presented.

Main types of screwdrivers

Under the general name “screwdriver”, consumers often mean several types of such a tool, which, despite the general similarity of functions, still have differences. So, three main types can be distinguished:

• Electric screwdrivers.
• Electric impact wrenches.
• The most universal - drills and screwdrivers. Some models may also be equipped with a shock function.

The most popular tools are those that operate autonomously, powered by rechargeable batteries. However, it is quite possible to purchase a screwdriver that operates on a regular 220 V / 50 Hz network. Tools with a cord for connecting to an outlet are usually called “network tools”.

It is necessary to become more familiar with the main types - this will make it easier to make a choice, realistically representing the expected nature of the work, its intensity and the load on the tool.

Electric screwdrivers.

Although In terms of their main performance indicators and general functionality, cordless screwdrivers are to some extent inferior to standard ones drills and screwdrivers, they have their own specific advantages, which make these instruments widely popular among both professional craftsmen and amateurs. These invaluable “advantages” include low weight, compact layout of the device, and high ergonomics. This allows the use of cordless screwdrivers in conditions where the use of a larger tool is either associated with great inconvenience, or is even simply impossible.

Such a tool is becoming indispensable on production lines for the assembly of small household equipment, computer and office equipment; it is widely used by craftsmen in the production process or final assembly. Due to their compactness, ergonomics and low weight, such screwdrivers do not cause rapid hand fatigue, and are therefore very convenient for working at heights, including, for example, when installing suspended ceilings.

Cordless screwdrivers come in different designs. Many models have a cylindrical body, which, however, is equipped with a hinge joint that allows it to be folded, if necessary, to concentrate the pressing force of the hand.

Other screwdrivers have the usual “pistol” shape, but they are always very compact and fit comfortably in the palm of your hand.

In addition, very easy-to-use models are produced, in which a swivel joint is provided for the working head with a rotating chuck. This opens up the possibility of tightening fasteners or dismantling them in the most inconvenient places, where it is not possible to start a regular tool.

The compactness of such power tools is achieved through the use of small batteries, with a voltage usually ranging from 3 to 9 V. Screwdrivers do not have high rotation speeds - usually from 150 to 250 rpm. For their intended purpose, this is quite enough, as is a tightening torque of about 10 N×m. For the vast majority of fasteners, especially in domestic conditions, such indicators are more than enough. However, there are also more advanced models, equipped with a two-speed switch, and allowing drilling work with plastic and wood - their rotation speed can reach up to 600 rpm.

Almost all cordless screwdrivers are equipped with an adapter chuck for bits with a ¼-inch hex shank. Typically, bits for various types of fasteners, as well as small-diameter drills with the same hex shank, are included with the screwdriver itself.

Unlike larger tools, electric screwdrivers are often equipped with a non-removable battery located in the body of the product. For charging, a special power supply adapter is used, which is plugged into an outlet.

What's the result? If the owner has a good drill in his toolkit, and he only needs to mechanize the process of working with fasteners, then a cordless screwdriver can become very useful assistant. In terms of ease of use, it is superior to a screwdriver, but is significantly inferior to it in functionality.

Electric impact wrenches

Another type of tool that very similar to a screwdriver, and even in certain circumstances can be used as one, but still has features directly related to its intended purpose.

If a master, due to the specifics of his work, very often has to resort to installing or dismantling threaded connections of medium or large diameter, then limit himself to using wrenches- this means sharply reducing the productivity of your labor. A classic example is a fully operational assembly plant or, which is closer to private practice, car repair or tire shops. In addition, in particular, when repairing cars, very often you have to deal with old, “soured” components, which seem very difficult to unscrew manually, even after treatment with a special compound.

The solution is to use an impact wrench. Its design is such that, in addition to the usual rotational movement, impulse influences with a certain frequency are also transmitted to the working part of the spindle by a special mechanism. In a word, these are a kind of “micro-impacts” that can move and unscrew even very rusty nuts or bolts without violating the integrity of the edges of their heads.

Most impact wrenches have the usual “pistol” design, but can be additionally equipped with a removable side handle to concentrate the clamping force when breaking the connection. However, there are also “straight” devices, with a working head located perpendicularly - for performing operations in hard-to-reach places.

Of course, such operations require special drive power - usually it ranges from 350 W for the smallest tools and even up to 1300 W for professional-class devices. The rotation speed does not play a decisive role here, and it is usually small. But due to this, a high torque is achieved, which even for “weak” impact wrenches is about 200 ÷ 300 N×m (compare, for example, with the cordless screwdriver already discussed!), and in professional-class models, with an electric drive power of over 1000 W, this figure can even reach 1000 N×m.

In appearance, impact wrenches are very similar to screwdrivers, but they are distinguished by a feature - the absence of a maximum torque adjustment ring (“ratchet”). The working end of the spindle is also different - most often there is a square adapter for socket heads. The size of the square for different power models may vary - ½ (most often for household-class models), ¾ or even 1 inch (for a professional powerful tool), which means that sets of heads should be purchased accordingly. Although, there are special adapters for this case.

Some manufacturers immediately provide increased versatility of the adapter. So, in the center of the square spindle there may be a socket for inserting standard ¼-inch hexagons - shanks of bits or drills.

But even this does not add much versatility to the impact wrench. Its specific electromechanical characteristics are nevertheless “tailored” for specific operations. High torque, and even with a pulse mode, can be completely unnecessary and even harmful when working with materials that do not require excessive effort. A low rotation speed may not be sufficient for drilling work.

In a word, an impact wrench, if the specifics of the machine’s work require its frequent use, will be a good addition to a screwdriver, but it is unlikely to be able to completely replace it in a householder’s arsenal.

By the way, many famous manufacturers release tool kits, inwhich included and drill/driver, and an impact wrench, which are powered by one set of batteries. Here This is a truly universal set. True, its cost is quite high, and such a purchase must really be justified.

Drills and screwdrivers

This is the most common and most frequently purchased type of such tools, which has increased versatility.

The vast majority of such screwdrivers are made according to the basic “pistol” design.

1 – case made of impact-resistant plastic (some professional-class models have an all-metal case). Inside there is an electric drive with control elements and a sophisticated air cooling system.

2 – pistol grip. High-quality models have rubberized linings that prevent the tool from slipping in the worker’s hand and make the tool as comfortable as possible.

3 – rechargeable battery with a locking mechanism in the handle. In most models it looks similar to what is shown in the figure. However, some modern screwdrivers are equipped with powerful compact batteries, which are completely hidden inside the handle, making working with the tool even more comfortable.

4 – start key (trigger). Moving the trigger simultaneously smoothly regulates the rotation speed of the screwdriver spindle. Typically the trigger is also covered with a rubber or soft plastic cover.

5 – spindle rotation direction switch (reverse). It is designed so that the switching process is as simple as possible - just a finger effort is enough.

6 – gear switch, which allows you to change the operating modes of the tool - low speed with high tightening force, or, conversely, high-speed rotation necessary for drilling work. This function is not implemented in all models.

7 – chuck for clamping a working tool – bit holder or drill. The design of the cartridge may be different. Some models are not equipped with a chuck - they have a ¼-inch hex socket for standard bit shanks or special drills. The types of cartridges will be discussed below.

8 – chuck clamping jaws.

9 – required element of any screwdriver - a mechanism for limiting the torque transmitted to the chuck. Usually made according to the “ratchet” principle - when the set tightening torque is exceeded, the clutch slips with a characteristic sound. The number of torque setting positions can be different - from 5 ÷ 6 V inexpensive models up to two dozen or more in professional instruments. A drilling mode must be provided - when rotation is transmitted from the gearbox to the chuck without torque limitations. This mode is indicated by the corresponding icon.

10 – modern models screwdriver V They are increasingly equipped with an LED illumination system for the work area. Location LED may be different.

Thus, this type of screwdriver is the most versatile, which determines its wide popularity among professionals and home craftsmen.

What to look for when choosing screwdriver

When deciding to purchase one model or another drill-driver, the future owner of the instrument must clearly understand for what goals it is necessary, which operations are planned to be performed by him and with Which exploit intensity. It is these preliminary “outlines” that will become the basic points when assessing the characteristics of devices offered for sale.

Type of batteries and their characteristics

It is advisable to begin the consideration with the “energy” of the screwdriver. No matter how wonderful the tool itself is, its performance directly depends on the batteries, the cost of which, by the way, is always more than half the price of the entire set. Surely, many have had to deal with a situation where the screwdriver itself is still quite functional, but the way out is Troy power supplies creates a lot of problems. It is not always possible to find a suitable replacement - many manufacturing companies do not offer batteries for sale separately, apparently trying to encourage users to purchase a new set.

The main characteristics of rechargeable batteries for screwdrivers are voltage and capacity.

• From voltage directly The power of the electric drive and, accordingly, the maximum torque, which determines the functionality of the tool, depend. Thus, screwdrivers with a battery voltage of 9.6 are most often found on sale; 12; 14.4 or 18 V. This, however, is not the limit - for powerful professional tools You can find batteries with 20 or even more volts (up to 36). 9 volts still looks a little low even for household tools. The optimal solution for a screwdriver purchased for home use, most likely there will be a “golden mean” - with 14.4 V batteries.

By the way, you can find almost identical ones from the same manufacturer, differing only in the supply voltage and, as a result, power ratings. But even in this case, it should be understood that the batteries are not interchangeable - the electric drive is designed for a specific voltage, and exceeding it will lead to its failure.

• Battery capacity is measured in ampere-hours (Ah or Ah - you can find one or the other designation). Typically this indicator is indicated on a marking on the battery case, next to the voltage.

In essence, battery capacity is a value that shows how long a tool can operate on one fully charged battery, without recharging. Naturally, the larger this value, the less frequently you will have to interrupt work to replace the power supply and recharge the elements.

Typically for household grade screwdrivers used occasionally, a capacity of 1.2 ÷ 2 Ah is sufficient. For intensive use, this indicator will not be enough - you should look for kits with a battery capacity of 2 ÷ 3 Ah.

The performance characteristics of batteries directly depend on their types. This issue requires closer consideration.

• Nickel-cadmium batteries (Ni-Сd )

Due to their low price, such batteries remain leaders in widespread use in middle-class power tools, despite the fact that they are being replaced by more advanced batteries.

Advantages nickel-cadmium batteries are as follows:

• The already mentioned low manufacturing cost.
• High resistance to negative operating and storage temperatures.
• They are the only ones in existence that are not afraid of an absolutely complete discharge. Nickel-cadmium The battery can be stored in a discharged state - and after that it will be fully restored after proper charging.

They have plenty of disadvantages:

• Inability to achieve high specific capacitance. A figure of 2 Ah, at best, will be already limiting.
• Quite a short overall “life” - even high-quality Ni-Cd batteries rarely withstand more than 1000 charge-discharge cycles.
• Such batteries are prone to self-discharge - if used infrequently, you may encounter the fact that a seemingly fully charged battery from storage is “dead” and cannot cope with its task.
• The most important “illness” of such batteries is the “memory effect”. It is unacceptable to charge a battery if it has not completely exhausted its resource. The fact is that when a charge is not received from “0”, the remaining charge level is still perceived by the device as the minimum value. Thus, the capacity of a fully charged battery spontaneously decreases by the amount of previously undeveloped potential. It is necessary to completely discharge the battery in one way or another (for example, by connecting a light bulb or a flashlight that is often included with the screwdriver), and only then insert it into the charger. This can be extremely inconvenient, especially in situations when it seems that the power of the tool is already starting to not be enough, and “your hands are reaching out” to charge the battery.
• Improper disposal of waste nickel-cadmium batteries can cause harm to the environment.

Nevertheless , nickel-cadmium Batteries are considered faithful “workhorses”, and are most often installed on household-class models. In such operating conditions, their qualities will be quite sufficient.

• Nickel metal hydride batteries (Ni-MH )

Nickel metal hydride batteries are an attempt by battery developers to get rid of the main disadvantages of Ni-Cd. But it is still impossible to say with full responsibility that this is a successful step.

The advantages of such batteries:

• Their production and disposal are environmentally friendly.
• High charge capacity, which can easily reach 3 Ah. And this coupled with the more compact size of the battery itself. Accordingly, the power density of the power source is higher.
• The negative memory effect is no longer so significant, oneako, It was not possible to completely get rid of it.

Negative aspects of such batteries:

• Their price is significantly higher than that of nickel-cadmium.
• Low duration of “active life” - the number of recharge cycles rarely exceeds 500.
• Such batteries are characterized by a high level of self-discharge - the drop can reach 10% in the first day of storage after a full charge.
• The performance of batteries decreases sharply when operating in subzero temperatures.
• It is unacceptable to store such batteries in a completely discharged state.

In a word, the high price for such batteries seems unjustified. It is better to purchase or a cheaper running option - nickel-cadmium, or don’t skimp and choose a screwdriver with lithium-ion batteries.

By the way, nickel metal hydride batteries have not received much development, and tool kits with them are quite rare on sale - due to the low demand for them.

• Lithium-ion batteries (Li—Ion)

These are the most modern and, accordingly, perfect batteries for autonomous power tools.

The advantages of such batteries are as follows:

• There is practically no memory effect, meaning the battery can be recharged at any degree of discharge.
• Among all other batteries, lithium-ion batteries have the highest charge capacity and power density.
• Charging speed is the highest.
• But the effect of self-discharge is extremely weak. It is considered normal that over a year of storage under normal conditions, a high-quality lithium battery can lose no more than 20% of its charge.
• The active life span, the permissible number of charging cycles of such a battery is three times, or even more, superior to similar indicators nickel-cadmium.

There are also several disadvantages:

• High cost is a rather conditional disadvantage, since high performance indicators justify it.
• The operating temperature range of lithium-ion batteries is quite wide, and they can be used in frosty conditions (although they lose some of their characteristics). But they will not accept charging at subzero temperatures.
• A complete discharge of the battery is strictly unacceptable - it will not be charged from scratch. Manufacturers take this drawback into account and equip their products with special built-in electronic circuits that will prevent complete discharge. Moreover, very widespread The trend is to equip batteries with charge level indicators - this makes it easier to visually monitor them.

When choosing the right model, it is best to purchase a kit that includes two batteries. This way, you can ensure the continuity of large-scale work - while one battery is on the screwdriver, the second one is being charged. However, when using Ni-Cd batteries, you should always keep in mind the need to completely discharge them, so as not to cause a “memory effect”.

Very often, in the technical documentation of a product, the manufacturer indicates the average duration of charging batteries - the shorter it is, the more convenient the tool will be to use.

Well, those users who do not want to deal with batteries, and who are not afraid of the power cord extending from the tool, are advised to purchase a network model.

The performance characteristics of the tool do not suffer from this, but the convenience, of course, somewhat smaller. When choosing, you only need to pay attention to the length of the cord - so that it is enough for the specific conditions of the intended use.

Electromechanical qualities of a screwdriver

• A few words about the drive. Most models in the low price range use an old and proven scheme with a brush collector. Such engines are quite reliable, but still not without drawbacks. And the main one is significant frictional forces at the contact point of the brushes to the commutator lamellas. Naturally, this is accompanied by a significant release of thermal energy, and the drive heats up quite quickly. In addition, sparking of the brushes on the commutator cannot be ruled out, especially if you have to work in conditions of high air humidity.

The electronically controlled brushless motor does not have all these disadvantages. Absence additional plot friction leads to a dramatic increase in tool performance. So. Tests of similar models with batteries with exactly the same characteristics showed that a screwdriver with a brushless motor performed almost three times more work than with a commutator motor.

Some manufacturers (for example, DeWalt) decided to get rid of the motor housing - all its components are located directly in the body of the screwdriver itself. And this is not a trifle at all - there was a significant gain in total mass a tool that has become much more convenient to work with.

So, if there is a choice between a conventional and brushless drive, it would be wiser to make a decision in favor of the latter. True, this is reflected in the price of the instrument.

• When choosing, be sure to clarify what materials the screwdriver gearbox is made of. This mechanical unit bears the heaviest loads, and its quality will determine the functionality and overall “life” of the entire tool.

It cannot be said that plastic gears are of poor quality, but still their service life is less than that of high-quality metal ones. And the deformation of even one tooth on any of the gears leads to jamming or complete destruction of the entire kinematic scheme gearbox So it’s better to make a choice in favor of metal ones.

• Characteristics of the rotation speed of the working spindle - they are always indicated in the product passport. It probably doesn’t make sense to chase too high indicators - for installation and dismantling operations with fasteners with 500 rpm is sufficient for excess, and for drilling wood or metal - about 1200 ÷ 1500 rpm. Higher speeds are inherent in professional tools for performing specific operations, and are unlikely to be in demand at the household level.

Rotation speed adjustment from zero to the maximum is produced by changing the force of pressing the trigger (key). For a more comfortable performance of basic operations, you should choose a screwdriver that has the ability to switch the gearbox to high and low speeds. Typically the switch is located on top of the case.

• Maximum torque is an important characteristic that determines the functionality of a screwdriver.

So, for working only with small fasteners, 10 Nm is enough, but this will be more like an electric screwdriver. In order for a screwdriver to be able to perform simple drilling operations, it is better to select a model with a maximum force of at least 25 Nm. Respectively. in cases where more is expected from the tool - for example, drilling wood with large diameter bits or metal, screws are chosen rt with a torque of 36 Nm or more.

For many consumers, torque values ​​expressed in newton meters. They may not say much. Therefore, in the technical documentation of screwdrivers, the maximum values ​​are usually indicated additionally. drill diameters, separately - for processing metal and wood. This will make it much easier to make your choice.

• Torque adjustment (tightening torque) is available on almost all screwdrivers. As a rule, this is a rotating ring with a scale applied - from minimum value to the maximum used for drilling.

If the set force is exceeded, the ratchet or slip clutch is activated, and excess torque is not transmitted to the fastener.

The numbers on the scale only show the serial number of the specific switch position as the tightening torque increases, but are in no way related (as some inexperienced users mistakenly believe) with the diameters of the fasteners. The drill symbol indicates the maximum torque required to drill.

• There is a rotation direction switch on probably all models - without it there is no screw rt will simply cease to be so. Usually located above the start button (trigger). In some miniature screwdrivers (similar to a cordless screwdriver) two different keys can be provided - for direct and reverse rotation of the spindle.

Chuck type

Most modern screwdrivers are equipped with quick-release chucks, making it easy to change bits or drills.

Keyless chucks can be single- or double-clutch.

In a two-clutch chuck, when installing and removing a working tool, the lower clutch is held by hand, and the upper clutch is tightened or, conversely, released. It’s even easier to work with a single-sleeve one - the whole operation is performed with the movement of one hand. However, the screwdriver itself must be equipped with a spindle lock function. Such blocking can be automatic, triggered when rotation stops, or forced (there is a special button).

By the way, when choosing a screwdriver, you should definitely check whether the tool has the option of forced spindle braking - when the trigger is released, the rotation should stop immediately. Almost all modern tools are equipped with this function, but if you still come across an outdated model, the chuck of which continues to rotate by inertia after the power is turned off, you should not purchase it, as it will cause a lot of inconvenience in your work.

Jaw chucks, which require a special wrench to tighten, are rarely used with screwdrivers. The key tends to always disappear somewhere during work, and the process of replacing a drill requires a lot of time and additional effort. Nevertheless, many craftsmen include such a chuck in their kit, since sometimes for drilling that requires significant effort, the tightening force of the coupling chuck may not be enough.

If the choice is made with the expectation of minimum dimensions screwdriver and with its primary use for screwing fasteners, you can purchase a model without a chuck at all - with an adapter for a ¼-inch hexagon.

In this case, if you need to perform any small drilling operations, you can use a small chuck with an adapted hex shank.

Additional criteria for selecting a screwdriver

Many models of modern screwdrivers are equipped with additional useful functions.

• In addition to rotational force, an impact force on the tool chuck can also be provided. This allows you to drill holes in some building materials. Such screwdrivers have a switch between normal and impact operating modes. It can be located either on the tightening torque switching ring or placed separately.

Many models of screwdrivers with an impact function are equipped with an additional removable side handle to emphasize the forward force when drilling.

By purchasing a similar screw RT, it is still quite realistic to imagine that he can cope with brick wall or made of some kind of lightweight concrete (gas silicate). If you need to drill holes in reinforced concrete structures, for example, in the walls or ceiling of a panel house, then it is better to have a hammer drill for such operations.

• The presence of a pulse operating mode for the tool, similar to impact wrenches, can be a great help in the work. This allows you to deal with soured threaded connections or accurately mark the beginning of the drill’s entry into dense material.

The inclusion of the pulse mode can be on the torque adjustment ring, or it can be done in the form of a separate button, pressed as needed.

• An additional convenience when working will be the presence of built-in lighting. The LED “flashlight” can be located coaxially with the body, under the socket. However, as practice shows, this is not always convenient - the cartridge itself can obscure the work area.

Another location for the flashlight is at the bottom of the pistol grip. In this case, the light flow is directed in such a way that it completely illuminates the working area from below.

The convenience of a particular lighting scheme can be assessed when choosing a tool.

• The most important selection criterion is the weight, balance of the instrument, and its convenient location in the palm of your hand. If you plan to work at heights, then you should pay more attention to lightweight compact models. And in T For frequent drilling operations, the weight of the tool even becomes a definite aid in the work.

But in any case, when assessing the “pickup power” of a screwdriver in a store, you should evaluate the location of the center of gravity of the tool - moving forward or backward causes rapid fatigue of the hand.

Experienced craftsmen It is advised to evaluate the transition point from the handle to the trigger - it should have a smooth transition at an obtuse angle. A rectangular or sharp-angled transition will lead to rapid fatigue of the middle finger during large-scale work, and may even cause the formation of a callus on it.

• The equipment of the delivery set must be assessed.

— The set must include a charger with a power cord. Modern “chargers” are a well-thought-out electronic circuit that will prevent the battery from overheating and will automatically turn off when the upper charging limit is reached.

As noted above, you should not purchase a screwdriver equipped with only one battery. – this is extremely inconvenient to work with.

— The kit may include a flashlight - as additional lighting during work or as a device for the necessary complete discharge nickel-cadmium batteries.

— Screwdrivers are often equipped with special belts or even holsters for easy placement of the tool on the master’s belt when performing work at heights.

— To included bits and drills m Many professionals are very skeptical, preferring to purchase the necessary types separately. However, leading manufacturers equip their kits with fairly high-level equipment. True, the specification is not always sufficient, and the need for an additional purchase most often arises.

— Professional-grade screwdrivers can be additionally equipped with replaceable gear units. Example - model " FESTOOL C15» .

In addition to the adapter for hex bits, a quick-release chuck can be installed on the tool. In addition, the kit includes a gear attachment that allows drilling and tightening fasteners at an angle of 90°. More it is a replaceable attachment - it is an eccentric that transmits rotation to a drill or bits offset from the axis of the screwdriver. A very convenient function for working in a corner, where the body regular tool does not allow achieving perpendicularity of force application.

True, the price for such kits is very high.

Brands you can trust

An important selection criterion should always be the manufacturing company and availability in a particular region service of this brand. For example, the dynamically developing European company KRÜGER.

Prices and the lineup KRÜGER screwdrivers

The German brand KRÜGER offers three models of screwdrivers: 12, 18 and 21 V. KRUGER brand tools are increased in power, equipped with various functions and come with a rich set of accessories. 12 and 18 V devices work for drilling/tightening, the 21 V drill/driver is also equipped with an impact mode.

Professional cordless screwdrivers Kruger (https://shurupovert.krugerpro.ru) show excellent specifications. A high-capacity lithium-ion battery is installed inside, which allows you to use the tool for a long time. The drill-driver is equipped with illumination of the working area, so it can be used in the dark or in places with poor lighting.

The tool not only drills holes, but also screws or unscrews fasteners. The Kruger cordless drill/driver comes complete with a set of 13 bits and 7 drill bits, as well as a charger that charges the driver in just one hour. The presence of a reverse function allows you to quickly remove a stuck drill.

This is a compact and lightweight tool that every craftsman should have in his arsenal. Depending on the modification, prices for Kruger screwdrivers vary in the range of 4000-8000 rubles.

• Without any doubt You can purchase Makita screwdrivers - this company has always been a leader in the production of power tools.

• A wide range of models, from inexpensive household to professional tools, is offered by Bosch. Regardless of the class of screwdrivers, they are all distinguished by the highest quality and reliability.
• The AEG company's tool cannot be called cheap, but it fully justifies the money invested in it.

• Power tools from the DeWalt brand are always distinguished by the most innovative developments in this area.

• Metabo screwdrivers, as a rule, are full of electronics, including those that regulate the amount of torque.

• Hilti brand tools are high functionality, but still their price looks unreasonably high, despite the tempting manufacturer’s warranty.
• Are in wide demand and good feedback get affordable screwdrivers “Hitachi”, “Sparky”, “Skil”.

• Among domestic manufacturers, it is quite possible to put Interskol, Kalibr, and Zubr in this row. Perhaps in certain positions they are inferior to new products from the world's leading manufacturers, but in terms of reliability, availability of service and price level they are a very attractive choice.

But purchasing a “pig in a poke”, under an unknown nonsense, most often made in China, is, of course, a “lottery”. It is quite possible that such a screwdriver will last a long time and will fully cope with the tasks assigned to it. However, in case of failure, you cannot count on any technical support or warranty. Yes and with spare parts for independent conduct repairs can cause big problems.

And at the end of the publication - a very voluminous and informative video lecture on choosing the optimal screwdriver.

Video: the right approach to choosing screwdriver