What torque is needed for an electric drill. Which screwdriver is better to choose? Screwdriver speed

Almost every person at least once had to work with a screwdriver. Periodically, there is a need for minor home repairs, tightening a bolt, screw, self-tapping screw. However, if there are a lot of these bolts and screws, then manual tightening with a screwdriver becomes a very laborious undertaking. To facilitate this task will help such a good tool as a screwdriver.

A screwdriver is necessary in construction, repair, furniture assembly, etc. With it, you can drill holes and screw in screws and self-tapping screws.

On the modern market there are many models of this tool from a variety of manufacturers. And it is important to understand which screwdriver is better in order to choose the most suitable option. To do this, you need to know about the main characteristics of this tool and approach the choice with the utmost responsibility.

Main differences

For work at home for a short time, a household screwdriver is perfect.

Understanding which screwdriver to buy, you need, firstly, to be aware of the differences between models for domestic and professional use. There is an opinion among users that any tools that bear the title of "professional" are of better quality and more productive. As for the quality, everything, of course, is not so simple, but their opinion is correct about the performance. Having bought a professional-grade screwdriver, there is no doubt that it will serve for a long time, flawlessly performing everything that is required of it. However, the cost of a professional screwdriver is often several times higher than the price of a simple model for the home. And almost no one uses all the possibilities of professional-class models in everyday life.

For example, an average household screwdriver has a torque of about 15 Nm, and a professional one - 130 Nm. For tightening screws and other fasteners, a torque of 10-15 Nm is sufficient. Therefore, here you need to think several times whether it makes sense to overpay for something that will not be used.

Another difference between professional tools is more powerful batteries and chargers. It takes an average of 1 hour to recharge such a screwdriver. Plus there are fast charging modes. And if you are planning to buy a battery model, think about what is more important for you: saving money or time. Household models are charged on average 3-5 hours.

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Torque

One of the most important characteristics of any screwdriver is torque. This parameter indicates how much rotational force is exerted on the body, i.e. with what force the working element of the screwdriver rotates. This parameter is directly related to the length and diameter of the screws that can be screwed with such a tool, and the hardness of the material that can be processed.

This indicator is measured in Nm. Household models have a torque of 10-30 Nm. This value is more than enough for the vast majority of household tasks. Professional tools can have torque in excess of 100 Nm. Such a screwdriver will be able to twist fasteners into very hard materials. And if necessary, it can even be used as a drill.

It would be better if the torque change function is available. With its help, the user will be able to set the force that is best suited for a particular screw.

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Rotational speed

For tightening self-tapping screws and screws, the optimal rotation speed should be 400-600 rpm.

Another very important characteristic of any screwdriver is the speed of rotation. This parameter shows how many revolutions the working nozzle of the tool is capable of making in a selected period of time. That is, the higher the rotation speed, the faster it will be possible to twist and unscrew something.

For simple tasks with self-tapping screws and screws, a speed of 400-600 rpm will be sufficient. If you plan to use a screwdriver for drilling, look at models with a rotation speed of 1000 rpm.

Most modern tools are equipped with a torque control function using a special regulator. Be sure to pay attention to the screwdriver you like has such a function.

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Battery Models

Cordless screwdrivers are very handy. Network independence allows you to work even in the most inaccessible places. However, when choosing such a model, you first need to know that screwdrivers can be equipped with different types of batteries and that the battery life of the tool and many other characteristics directly depend on the battery. Pay attention to the type, voltage and capacity of the battery.

Currently, screwdrivers are equipped with the following types of batteries:

1. Nickel-cadmium.
2. Nickel metal hydride.
3. Lithium-ion.

If you do not follow the rules for charging the battery, then the nickel-cadmium battery will quickly fail.

Nickel-cadmium batteries are the most common and inexpensive. Such batteries require strict adherence to the operating mode. Their main disadvantage is the presence of the so-called. "memory effect". If the user does not fully discharge and charge such a battery, it will quickly become unusable.

Lithium-ion models are more expensive. They are devoid of the disadvantages of nickel-cadmium batteries, and they can be used without observing the charge-discharge regime. As for nickel-metal hydride batteries, they are used somewhat less frequently in screwdrivers. The memory effect is less pronounced, but the cost is noticeably greater.

A parameter such as battery capacity is measured in mAh. This characteristic determines how long the tool can work autonomously, i.e. without a network connection. And the higher it is, the better for the user. For household use, a tool with a 1200 mAh battery will suffice.

The electrical power and, as a result, the performance of the battery depends on the voltage of the battery. Voltage is measured in volts. The higher it is, the easier it will be for the tool to do what the user requires of it. To solve everyday tasks, a battery with a voltage of 12-14 V is enough. When choosing a professional model, pay attention to screwdrivers with a more powerful battery.

A charger must be included with the screwdriver.

Be sure to pay attention to the presence of a charger included with the screwdriver. The charger works in much the same way as a mobile phone charger. However, the main problem with cordless screwdrivers is that many of them can only work with the original charger. Therefore, treat it with care during operation.

Thus, among the advantages of battery models, one can single out the fact that they are:

1. Mobile.
2. Get rid of a lot of wires.
3. Allows you to work in any place where there is no power supply.

The main disadvantage is that, stored for a long time idle, the batteries gradually lose their life. Therefore, most users give their choice in favor of conventional models powered by the mains. Although they are heavier and less mobile, they eliminate the problems with storing and charging batteries.

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Chuck type

Keyless chucks are considered the most practical and convenient.

Screwdrivers, as well as drills, can be equipped with key and keyless chucks. Due to the fact that the load characteristics in screwdrivers are not the same as in drills, it is best to opt for a model with a keyless chuck.

Such a screwdriver is very convenient in that it allows you to change nozzles as quickly as possible. There will be much less downtime in the process, and the user will be able to solve the tasks assigned to him faster.

For a long time, screwdrivers have come to replace screwdrivers. If earlier these devices had a rather high price, today almost everyone can afford to buy such a tool at home or at work. But since choosing a cordless screwdriver is not as easy as it might seem at first glance, you need to contact professionals for advice.

What should every consumer know?

This power tool is simply indispensable for repair and construction work. The question arises: "But what about screwdrivers?" If modern construction organizations used such equipment, the construction or repair of the facility would be delayed for a long time. As for use in everyday life, for a more comfortable twisting or unscrewing of screws, it is necessary to use just such equipment. As you already understood, the screwdriver works in a narrow direction, or more precisely, with fasteners such as screws, self-tapping screws and dowels. But it was like that before, today, for an additional fee, you can purchase several nozzles, and the tool can partially replace the drill. Let's take a closer look at how to choose a cordless screwdriver, and what you need to pay attention to first.

Mains and cordless tools

A mains powered screwdriver can be used where there is an outlet. In the absence of it, you are unlikely to be able to twist or unscrew something. This is where the battery comes in. It is safe to say that such a solution gives more opportunities to its owner. For example, it makes no sense to buy a battery-operated hammer drill, but the situation is different with screwdrivers. Of course, the battery needs to be recharged periodically, but most often you get two batteries in the kit, so this should not be any problem. Whether there is an outlet or not - it will not matter to you, since you simply do not need it. Of course, over time, the battery will hold a charge worse and worse, but, most likely, by this time you will already have time to change the tool to a similar one, but more powerful and functional.

How to choose a drill driver? Step-by-step instruction

There are a number of parameters that you should pay attention to in the first place. The main one is power. It is worth noting that 500-700 W is enough for domestic use, but about 1,300 W will be needed to perform construction work. There are special drills for working in hard-to-reach places, their power is slightly less, about 400 watts. The number of turns is another important indicator. If 3,000 rpm is enough for work at home, then 4,000-4,500 rpm is needed for construction work. Regardless of the purpose, it is advisable to give preference to a model with the ability to adjust the speed, so you can adapt to the specifics of the work, because different materials need different speeds. Do not forget that a powerful tool rotates the drill faster, but the price also increases in direct proportion. However, this is not all that can be said about how to choose a drill driver, so let's deal with the issue to the end.

More about making the right choice

When buying, it is always necessary to specify the diameter of the holes that the tool can make. But here you need to understand that for each hole this indicator will be different, so focus more on what you will work with. If you want to get a hole of such a diameter that the drill is not designed to work with, you risk damaging the unit. Depending on your preferences, choose the type of cartridge. Now gear (fixed with a key) and quick-clamping (fixed by hand) cartridges are produced. There are practically no fundamental differences. Now you know what a cordless drill/driver is. We figured out how to choose a device, so let's go ahead and talk about the batteries used.

About Li-ion batteries

It's safe to say that battery type plays a huge role. Currently, this type of battery is one of the most popular and widespread. A lithium-ion battery is used not only in screwdrivers or drills, but also in other construction tools, as well as in portable devices (laptop, mobile phone, etc.). From this we can draw a simple conclusion that there are many advantages. One of them is durability. With proper use, the lithium-ion battery is rated for 3,000 charges/discharges. The maximum shelf life is approximately 3 years. It is difficult to say whether this is good or bad, but as practice shows, this is quite enough. How to choose the right cordless screwdriver? Everything is simple here: buy a good battery with a large capacity - and you will be happy. But do not forget that normal operation requires constant use of the device, so you need to use a screwdriver from time to time, at least for prevention. But there are other types of batteries, which we will talk about now.

How to choose a screwdriver battery? Ni-Cd

Nickel-cadmium battery is the most budget solution that can be. The number of charges / discharges is half that of a lithium-ion battery, and is about 1.5 thousand, but the service life is slightly longer - about 5 years. The main advantage of the Ni-Cd battery is that it works great at sub-zero temperatures, so you can safely operate the device until the mark on the thermometer drops below -15 degrees Celsius. But there are many downsides as well. For example, a long charging time. Although in some cases this can not be called a disadvantage. This is due to the fact that when buying a screwdriver with such a battery in the kit, you will receive 2 batteries. Therefore, while one is on charge, the second can be used. But even despite the low cost, it is necessary to follow some rules: keep the battery only charged, as well as fully charge and discharge it. This is due to the fact that the nickel-cadmium battery has a memory effect.

Ni-Mh: advantages and disadvantages

Ni-Mh (nickel-metal hydride) batteries are quite rare in today's screwdrivers. At its core, this is something in between the two above-described batteries. Among the shortcomings, it is worth highlighting the large weight and a small number of charge / discharge cycles (1,000). The term of work is on average 4 years. As for the advantages, this is the absence of the memory effect and the minimum self-discharge during storage. However, despite this, it is recommended to fully charge and then discharge the battery before first use. Do not forget to pay attention to the capacity, which is measured in Ah (Amp-hours). The higher the indicator, the longer the battery will perform its immediate task. In order to understand how to choose the right drill driver, you need to decide on the type of battery. If you do everything right, you will not experience any problems.

What to choose for industrial purposes?

And now let's talk a little about how to choose a professional screwdriver. The fact is that it is important to pay attention not only to the power and type of battery, but also to the presence of useful additional features, and there are plenty of them in modern models. Often this should be a lightweight model that can easily work in hard-to-reach places, while the worker will not get tired too quickly due to the large weight of the tool. By the way, as for the type of battery, it is definitely lithium-ion. In construction, a percussion mechanism will be very useful. This feature is extremely relevant when drilling stone or brick. Professional builders or repairers are often faced with the fact that there is no way to rest well to make a hole. Even worse - it happens that the self-tapping screw will get stuck in place and neither here nor there. You have to start everything from the very beginning. In order not to experience this kind of discomfort, an impulse is needed. This function temporarily increases the torque, which allows you to get out of a difficult situation. Working in poor light is poor performance and poor accuracy. To solve this issue, buy a tool with a backlight. Well, that's all that can be said about how to choose a cordless screwdriver for professional use.

About chucks and gearboxes

Today on the market there are screwdrivers with the following types of cartridges:

• Quick-release (three-jaw with a clamping range of not more than 1.3 centimeters).
• Hexagonal. In this case, it is possible to work with a large ¼ inch shank.

Quick-release chucks are more common due to their practicality. No problem, you can use any tool that is suitable in diameter. If you buy a cartridge with a large diameter, then the screwdriver will have more opportunities. As for the hexagonal options, this is a good solution for professional tools where frequent tool changes are required and there is a need to work in hard-to-reach places. In principle, from the foregoing, a completely logical conclusion can be drawn: a quick-release chuck is suitable for the home, and a hexagonal chuck for professional use. As for the gearbox, then everything is quite simple. Gears come in two varieties: plastic and metal. Today, plastic alloys are quite durable and not so expensive. The question may arise as to how to choose a screwdriver for the home according to this parameter. Plastic is perfect for household purposes, and you won’t have to overpay. The metal gear will withstand a much greater load, so it is better for prof. tool.

Soft and hard torque

In this article, a little has already been said about the power of a screwdriver. I would like to add this information. The point is that there is a soft torque. It affects the twisting / twisting forces. Often this parameter is not paid much attention, but in vain. Insufficient force can lead to the fact that the self-tapping screw will not be completely twisted, and you will have to get it out at the final stage with your hands. Modern models have a fairly large spread in the range of 0-350 Nm. For domestic purposes, 30-150 Nm is quite enough, for professional purposes - everything above. The hard torque is responsible for the RPM during drilling. As a rule, this indicator fluctuates in the range of 1,000-4,000 rpm. Let's look at everything with an example. A screwdriver with a torque of 35 Nm is able to screw a 70 mm self-tapping screw into wood, and for a 100 mm self-tapping screw, a force of 50 Nm is required. After that, it should be very clear to you how to choose a cordless screwdriver.

Conclusion

As you can see, there is nothing complicated here. The most important thing is to highlight the main parameters for yourself, such as power, torque, battery type, capacity, etc. After carefully analyzing all this, you can easily make a thoughtful and, most importantly, the right choice. Do not forget that tools for home and professional use differ in many ways, so often experts prefer more powerful and functional models. From this article, you learned about what a cordless drill/driver is, how to choose a tool and not make a mistake. Currently, the following companies are considered the best manufacturers: Bosch, Skil, DeWALT, etc. A screwdriver with the inscription of one of these companies on the body will cost a lot, but in return you will get high quality, excellent ergonomics and just a good tool. That, perhaps, is all that can be said about how to choose a good screwdriver.

The choice of a screwdriver (cordless screwdriver) is a completely solvable task. To do this, you need to know what characteristics you need to pay attention to when choosing. First, we determine whether a household or professional model is needed. If you buy a screwdriver for small jobs around the house, for work in the country, etc., then your choice is a household screwdriver. If the screwdriver is supposed to be used intensively for a long time, then you need a professional screwdriver. This material will tell you how to choose a screwdriver.

Let's return to the main characteristics that you need to know when choosing a cordless screwdriver:

Motor voltage screwdriver. Modern models of screwdrivers have a motor voltage from 7.2V to 24V (Volt). The higher the voltage, the less current is needed to obtain the desired power. Accordingly, it is easier to get more power in a screwdriver with an 18V motor, and not 12V or 7.2V. It is worth clarifying that the most popular screwdrivers with a 12V, 14V and 18V motor.

Torque screwdriver. Torque is measured in Nm (Newton per meter). In simple terms, torque is the force with which your screwdriver screws screws. The more torque, the more options the screwdriver has. In modern household screwdrivers, as a rule, the torque is 10-28Nm. This is quite enough for housework. With a torque of 28-30Nm, a screwdriver can screw in 100mm self-tapping screws and drill wood with metal. Speaking of drilling in wood and metal, modern household models are capable of drilling holes up to 20mm in wood and up to 13mm in metal. In professional screwdrivers, the torque reaches 70-140Nm.

Most screwdrivers have a function torque adjustment. It is used where more control is required when performing certain jobs. Adjustment occurs by switching the ring located on the body of the screwdriver, at the base of the cartridge. On the ring there are numbers indicating the modes in the torque setting. The "drill" icon after the maximum number on the ring indicates the drilling mode.

Using the example of tightening self-tapping screws, the function is used as follows:

When screwing screws of different lengths, one torque is not needed. For smaller screws, a smaller tightening force is sufficient, and for longer screws, a correspondingly greater tightening force is sufficient. Most likely, everyone who twisted a screw into a tree at least once, but sunk it into the material. And where it is necessary that the surface be even and smooth, dents are not allowed. When the so-called “ratchet” is triggered, and this happens when the set torque is too high, the screwdriver stops turning the screw. This allows more precise control over the process. This function also protects the motor from overload.

Accumulator battery screwdriver. It is the battery that allows you to work mobile and not depend on the length of the cord. Screwdrivers use three types of batteries:

NiCd(nickel-cadmium) - such batteries are the most affordable, but the characteristics are simpler than those presented below. The capacity of such batteries is from 1.2 or 1.5 A / h (Amp hour). A screwdriver with a capacity of 2.0A / h under the same conditions is able to work longer than a screwdriver with a battery capacity of 1.2A / h. Capacities of 1.2-1.5A / h are enough for home use. And considering today's battery charging time is 1 hour, you will always have a "fresh" battery at hand. Of the minuses: require a complete discharge.

NiMh(nickel-metal hydride) - these batteries are more expensive, but their capacity is higher from 1.5 to 2.6A / h. Suitable for home use, as well as for more complex and prolonged use. Does not require full discharge.

Li-Ion(lithium-ion) - batteries are the most expensive, have a high capacity, which is higher than 3.0A / h. Another advantage of Li-Ion batteries is their light weight. The difference in weight can be up to 40%. Li-Ion batteries do not have a memory effect, which allows you not to wait until the battery is completely discharged.

It is worth saying that the warranty does not apply to batteries, as they often fail due to the fault of the buyer. If you leave the battery at a low temperature at least overnight, you may not be able to use such batteries. Store batteries in a warm environment.

Speed screwdriver. Different types of work require different speeds. For drilling, higher revolutions of 1000-1300 rpm are needed. For tightening screws, 400-550 rpm is enough. Screwdrivers come in single speed, two speed and three speed. Switching speeds allows you to work with the speed you need to solve various problems.

So. If you choose a screwdriver for the home, then a 12-14V screwdriver with a battery capacity of 1.2-1.5A / h and a torque of 15-26Nm is suitable here. Such a screwdriver can handle almost any job around the house. There are household screwdrivers with such characteristics from 1300 to 3000 rubles. You should not chase a low price, as a rule, the price tag for a screwdriver below 900 rubles indicates that such a screwdriver will not work for a long time. When choosing, pay attention to the recognition of the manufacturer, the terms of the guarantee, the number of service centers. Well, the screwdriver itself should be held in your hand, turned, pressed, etc.

When buying a screwdriver or hammer drill, you need to pay attention to many criteria. You can purchase an ordinary household tool that is suitable for minor repairs, but it is also possible to choose a professional or universal one, the power of which is greater. When choosing, attention should be paid to what maximum torque of a screwdriver or punch is provided, otherwise the tool can be broken in the first hour of fruitful work.

Screwdriver speed

The maximum torque of a screwdriver is a value indicating the load level. It is different for professional and home devices. But most often it is 5-10 Nm (Newton per m), which is quite enough for high-quality, safe operation of a screwdriver. This is enough to ensure work even with very tight self-tapping screws, when drilling such surfaces, such as concrete or steel, when creating holes with large diameters.

What should be the maximum torque of the screwdriver? If you need a universal screwdriver, then the torque must be chosen quite high, so that with the help of the device it is possible not only to screw in self-tapping screws, but also to drill holes with a different diameter from each other.

If a man is a jack of all trades and likes to independently carry out repairs in his house, then he probably has a complete set of necessary tools. Among them, a screwdriver - depending on its power, it can also be called an electric screwdriver and a drill - occupies a significant place. Those who make often or do such work all the time have long appreciated the undoubted advantages of a cordless screwdriver, its convenience, mobility and ease of use. Do you know how to choose the right cordless screwdriver so that it becomes your reliable assistant in household chores?

What is this tool and what is it for?

Whether you live in an apartment or a private house, you still have to carry out minor repairs from time to time. And this is where a screwdriver comes to the rescue - a hand-held electric tool with adjustable torque, that is, the force with which it can:

• drill holes in surfaces of almost any material - drywall, soft and hard wood, concrete and metal;
• screw and unscrew any fasteners - screws, self-tapping screws, nuts, screws, bolts;
• tighten anchor bolts during installation;
• cut threads in small metal parts.

Professional builders and repairers use screwdrivers regularly. It is difficult to imagine a more convenient tool for fixing, for example, drywall sheets during finishing work, installing windows and doors. In general, a screwdriver is necessary in any home where they are used to solving construction and repair issues on their own.

Cordless screwdriver consists of the following elements:

• housing with an electric motor that provides rotation;
• clamping cartridge;
• a rotary coupling attached to the gearbox, which regulates the twisting force, with a scale applied to it, in the common people - a ratchet;
• nozzle bits (screwdrivers), which are fixed in the cartridge, as well as additional nozzles for drilling holes and threading;
• tool start button;
• rotation speed switch;
• reverse switch (reverse);
• removable battery.

With a cordless screwdriver, you can work anywhere in the apartment

Why is it worth giving preference not to the usual, but to the cordless screwdriver? Devices powered by a wall outlet are not limited in operating time, you do not have to charge them. But they have a significant disadvantage: with such a screwdriver, you will not go far from the outlet. Of course, you can use an extension cord, but you have to adjust to the constantly interfering cords. Cordless screwdriver will not cause such inconvenience. You can easily work with it anywhere in the house, yard or take it with you somewhere where there is a need for work, but there is no electricity. Mobility is an indisputable advantage of such a tool. True, the operation of such a screwdriver directly depends on the battery charge level, but high-quality batteries significantly increase the operating time of the device.

Any power tool is a device with certain functions necessary for work, and this significantly affects its price. The cordless screwdriver is no exception. If you buy it for regular use, you need to pay attention to the characteristics of the device, which will become the main selection criteria:

• the shape, ergonomics and size of the tool, as well as its weight;
• type of battery and its capacity;
• indicator of maximum torque (effort);
• the presence or absence of a shock function;
• the maximum possible diameters of drilling in wood and metal;
• device equipment.

In addition, of course, you should take into account the price of the product and the name of the manufacturer. But we will talk about these parameters later, and now we will consider in detail the listed criteria.

The indicator of the number of speeds, according to experts, is not decisive when choosing a tool. Most screwdrivers have two speeds, but due to the presence of other working settings, the difference in the course of work is not always noticeable.

Most modern models of cordless screwdrivers have keyless chucks, which are suitable for any bits and drills. Some models have sockets for hex bits. The choice of cartridge, as a rule, is motivated by individual criteria for ease of use, it cannot be said unequivocally that one type is better and the other is worse.

Shape, size and ergonomics

These characteristics may not seem the most important to you if you do not classify yourself as a home craftsman. But for professionals who work with a screwdriver all the time, they are very relevant. For example, tool size. Its importance can be seen from two sides.

Screwdrivers of small size are very convenient due to their relatively low weight. With such a device, you can easily get into hard-to-reach places, and your hands do not get tired at all. But small screwdrivers do not have much power, and therefore it will be more difficult for them to screw a self-tapping screw into a hard material.

Smallest cordless screwdrivers - hammerless screwdrivers - light and easy to use

Larger instruments, unless they are the simplest cheap models of unknown brands, tend to be heavier and more powerful. The relative inconvenience of their use is offset by the ease of working with durable materials. If you often have to drill, then large powerful models are your choice.

Large, powerful cordless screwdrivers suitable for professional construction and repair work

Before buying, think about how often you will use a screwdriver. If you need it several times a month for small household tasks, you should not purchase an expensive large-sized model with high power. It is better to take a compact tool from the budget line.

The ergonomics of the tool is also very important. In some cases, you may have to hold a working screwdriver in your hand for several hours, and its weight, as well as vibrations, will affect your hand fatigue. The location of the barrel relative to the handle largely determines how comfortable it will be for you to use the tool. Before buying, hold the screwdriver in your hand, twist it to the sides, simulating work.

When choosing a cordless screwdriver, consider what duration and intensity of work you will perform with it.

In some models, the angle between the handle and the barrel is sharp; after prolonged work with such a screwdriver, calluses may appear on the palm of your hand. The location of the handle at a right or obtuse angle is much more convenient.

Battery type and capacity

Since we are talking specifically about cordless screwdrivers, then the heart of the tool - the battery - needs to be discussed separately. The quality of the device depends to a large extent on it. There are three types of batteries on the market today:

• nickel cadmium (NiCd),
• nickel-metal-hybrid (NiMH),
• lithium-ion (Li-Ion).

Naturally, each type has its own advantages and disadvantages. How significant they are in a particular case is a purely individual matter, but it is worth considering them in detail.

Table: comparison of batteries of different types

Of course, for home use, buying an expensive tool with a lithium-ion battery is not always advisable. The most objective choice would be a screwdriver on a nickel-metal-hybrid or nickel-cadmium battery. But if you are professionally engaged in repair and finishing work, it is better to pay attention to models with a lithium-ion battery: the price will pay off quickly, and you will get a convenient and most reliable tool.

Lithium-ion batteries are characterized by long life, high capacity and no "memory effect"

Battery capacity is also an important parameter. Most often, inexpensive models of screwdrivers are equipped with a 1.3 A / h (Amp / hour) battery. For example, if you are assembling a drywall ceiling at an average pace, one charge of such a battery will be enough for 3-4 hours. And since the charging time is less than an hour, you can not be afraid of downtime in work. Mega-power impact drivers are equipped with 2 or 3 Ah batteries. Many of these models do an excellent job of drilling metal and hard wood.

For the simplest screwdrivers intended for use in everyday life, the maximum rotation speed of the chuck is about 500 rpm, while for professional powerful tools it reaches 2000 rpm.

The optimal battery voltage for a screwdriver is in the range of 10-14.4 volts. The larger it is, the higher the maximum torque will be.

Torque - adjustable ratchet force

The concept of torque defines the force applied by the tool relative to the screw being screwed, or the force of resistance to the load. For domestic use, screwdrivers with a torque of 10–15 N m (Newton meters) will be optimal. For professional models, this figure reaches 130 N m, so they do a good job even with drilling very hard materials.

The higher the torque of the screwdriver, the better it will cope with drilling in hard materials.

For screwing conventional self-tapping wood screws up to 150 mm long, a force of 10–15 N m is sufficient.

According to the simplest logic, the higher the battery voltage, the more torque the tool has. However, this is not the case with professional models, for example, many 12-volt models have high torque - from 24 Nm and above. Whereas for simple household models, in order to achieve a force of 20 N m, the screwdriver must have increased power, most often this is the level of 18–24 volts.

A clutch for adjusting torque, with a scale applied to it, usually from 1 to 20, is called a ratchet. It works on the same principle as shifting gears in a car. The smaller the number set on the ratchet, the less force the tool uses to tighten the screw. With the help of a ratchet, you set the tightening torque limit, above which the engine starts to idle, and the rotation of the cartridge stops. You need to know that the scale of numbers on different screwdrivers indicates different levels of torque, that is, position “3” for one tool does not match the position “3” for another in terms of force.

It is worth making several test runs before starting work, changing the ratchet indicator, and only then, having chosen the right position, get down to business.

Impact function and drill diameters

Both the length and diameter of the screw being screwed depend on the torque indicator. The more powerful the tool, the thicker and longer screws they can tighten. In addition, you can drill hard materials with such a screwdriver. For example, a device with a torque of 36 Nm will perfectly drill wood with a drill with a diameter of up to 25 mm. A torque of 80 Nm indicates that the tool will cope with drilling holes with a diameter of 65 mm.

The overpayment for the impact function of a screwdriver is relatively small, so it makes sense to purchase such a tool for working at home. It will perfectly cope with drilling not only wood, but even metal in small volumes.

If you are engaged in construction and you need to drill a lot of holes in concrete, then it is still better to buy a hammer drill: even the most powerful screwdrivers will not cope with such work.

Equipment

The standard minimum set in which screwdrivers are supplied usually includes:

• plastic case;
• the screwdriver itself;
• batteries in the amount of 2 pieces;
• Charger;
• bits (from 1 or more pieces);
• instruction.

Some manufacturers may add a flashlight and an extra set of bits as a bonus.

Some manufacturers offer an extended set of screwdrivers with a convenient case, a flashlight, an additional set of nozzles

Rating of cordless screwdrivers from different manufacturers

The modern market for power tools offers a huge range of cordless screwdrivers from both world famous brands and less popular companies. We offer you a rating of these devices, compiled based on the materials of the Yandex.Market resource.

Table: popular models of screwdrivers