Screwdriver torque: theory and practice. Choosing a screwdriver The maximum torque of a screwdriver which is better

For some jobs, you have to tighten a lot of screws. You can, of course, do this manually with a screwdriver, but this requires considerable effort and takes a lot of time. To speed up the process, you need to choose a screwdriver. There are quite inexpensive models- household - which, nevertheless, greatly facilitate the installation and dismantling of screws. And some can work in drill mode.

Household or professional

As you know, professional screwdrivers are more expensive, but this is no coincidence. They are made with a large margin of safety, for which better and more expensive materials are used. In addition, they have more power, which makes it possible to drive longer self-tapping screws and / or work with harder materials.

To decide whether you need a household or professional screwdriver, estimate the amount of work that will need to be done. If you are building or overhaul probably need a professional or semi-professional model. If the tool will be needed periodically - unscrew / twist something from time to time, household is more than enough. With such work, the resource of a pro tool simply will not be in demand. So choosing a screwdriver according to this criterion is not very difficult.

Battery or mains

Having decided on the class, you will need to decide whether you need a cordless or cordless screwdriver. The disadvantages and advantages of both are obvious: the battery has higher mobility and the cord does not interfere with work, but it weighs more. The network does not depend on the presence of a battery charge, but not all construction sites have power supply. IN general choice difficult. The decisive moment may be cordless screwdriver with a good battery is decently more expensive than a similar model powered by the network. The difference is formed due to the presence of a battery - good options are not cheap.

If you decide to choose a power screwdriver, pay attention to the length of the cable. The longer it is, the more convenient it will be to work - you don’t have to carry a carrier.

To choose the right screwdriver on batteries, you need to pay attention to the type of battery. This determines the duration of work on a single charge, as well as the order of storage.

• Lithium-ion (Li-lon). Holds a charge for a long time, charges quickly, has a large number of recharges, almost does not discharge during storage. All in all, a good option but expensive. Because, probably, it is more common on professional models, where the duration of work on a single charge is important. The disadvantages include the fear of cold, which is important in our country.

  

• Nickel Metal Hydride (Ni-MH). This type of rechargeable batteries is environmentally friendly, they are small in size and weight, and have an average price. Disadvantages - they also do not like low temperatures, they have a short service life - about 3 years. But it is easier to work with such a tool - the hand is not so tired. When storing the battery, the battery is fully charged; discharged batteries cannot be stored. During storage, they are discharged, but moderately.

  

• Nickel-cadmium (Ni-CD). Main advantages - low price and the service life is 5 years (the number of charges is about 3000), it is not afraid of frost, that is, you can work outside in winter. Disadvantages - takes a long time to charge (it takes twice as long to charge batteries of other types), has a "charge memory". Charge memory is a nasty thing. If you charge a battery that is not fully discharged, then the total capacity of the battery will decrease. It will become less just by the value from which the charge began. Therefore, it is necessary to work with such a tool until the battery is completely discharged, which is far from always convenient: it cannot always “tighten” the screw, you have to help with your hands or tighten it with a “fresh” battery. Store fully discharged for storage, otherwise the capacity will decrease again.

  

  Most cheap type batteries - nickel-cadmium, but they have a "charge memory"

So, if you choose a cordless screwdriver for occasional work, a nickel-cadmium battery will do just fine. If used carefully, it lasts a long time. If you start large-scale work, it is better to use other batteries - there will be less downtime, the work will move faster.

Cartridge type

There are two types of screwdriver chuck: key and quick-clamping. Quick-clamping (usually has three petals) allows you to change nozzles in a matter of seconds - the cartridge is turned a little by hand, the nozzle changes, after which it is again turned a little in the opposite direction. In addition, there is one more positive moment: in such a holder it is fashionable to install a nozzle of any thickness. The main thing is that the shank fit into the holder.

The same operation with a key cartridge requires a special key. It is inserted into a special socket, rotated until the nozzle is released. After replacement, the key is turned in the opposite direction. The disadvantage is obvious: you need to have this key on hand.

By structure, keyless chucks can have one or two clutches. If there are two clutches, one of them fixes the cartridge, the second - the shaft. If there is only one clutch, then there is a shaft lock button on the body.

It is not difficult to choose a screwdriver according to this parameter - usually everyone converges on quick-clamping ones. They allow you to fix nozzles of large sizes, though they are, all other things being equal, a little more expensive.

Technical specifications

Once you have decided on the type of screwdriver and power, you need to focus on the technical specifications. They determine which screws and what material you can screw into.

Rotation speed and torque

The force with which a screwdriver can turn a screw is determined by the torque. It can be quite small for household models - 10-15 Nm, and can reach 130-140 Nm for professional ones. Because pro screwdrivers can easily and quickly tighten large self-tapping screws and work with hard materials.

But a large torque is not always necessary and not with all materials, therefore, screwdrivers provide the ability to adjust the applied force. There is a limiter for this. It is made in the form of a movable ring, which is located behind the chuck.

There is a mark on the ring, setting it opposite a certain number, you set the maximum force that the tool can develop. Upon reaching this value, the cartridge will scroll to idle - the screw will no longer be twisted. The achievement of this value can be clearly tracked - the ratchet is turned on.

Many models of screwdrivers can work in two modes: the actual tightening of fasteners and drilling. Such models are called a screwdriver-drill, but they are now the majority. To switch to the drill mode, the switch is set to its extreme position (having previously replaced the nozzle). This turns on the maximum speed, which allows you to drill even fairly hard materials.

Screwdriver power

Both the torque and the speed of rotation are a consequence of the power of the electric motor. Therefore, you need to look at this parameter as well. But here it is necessary to monitor three quantities at once: so that the power of the screwdriver corresponds to the speed parameters. Powerful models with good parameters can be found from many manufacturers, but such as Metabo (Metabo), Bosch (Bosch) and Makita (Makita) and other well-known prices for them are very high. There are other brands with similar characteristics, but more reasonable prices. For example, RYOBI (Ryobi). The brand is still little known, but according to reviews, it is no worse than the above-mentioned famous brands. In order to be able to compare the main characteristics and price of models of approximately the same power, but different brands Let's put them in a table.

It is worth saying a few more words about the number of speeds of work. Do not confuse with the number of rotation speeds. These are the two modes of operation that are used when working with different sizes screws or drills. When working with small screws / drills, you can select a higher speed, when driving large self-tapping screws or drilling big holes- smaller.

Battery Options

To choose the right screwdriver with batteries, in addition to the type of batteries, you must select their operating parameters:

To choose a screwdriver for home or professional use and not regret it, you must look at these parameters. If you have selected several models, compare them according to these characteristics, because it depends on them how long the interval between screwdriver battery charges will be.

Additional functions

As usual, these features are optional, but they greatly improve usability. Some prices, if they raise, are not at all significant, and some are quite noticeable. To choose the most inexpensive screwdriver, you can get by with a minimum - reverse and the presence of illumination of the place of work. The rest, of course, are useful, but are more suitable for professionals.

Reverse or reverse

The presence of this option allows you to unscrew a screw or a drill stuck in the material. The direction of rotation is changed by changing the polarity of the power supply, which is carried out through a special button. It is usually installed close to the trigger lever.

Most often, the travel direction switch button has three positions: on average, the tool is blocked. This increases safety: if you accidentally hit the lever, the screwdriver will simply stop and not immediately start to rotate in the opposite direction.

Illumination of the working area

A very convenient option that does not really affect the price of a screwdriver is the illumination of the place of work. With good lighting, it is much easier to control the instrument.

Illumination of the work area is a useful additional function of a screwdriver

An LED is built into the handle or body of the tool near the cartridge, which lights up when the start button is pressed. If you want to choose a screwdriver that is convenient to work with, make sure that there is a backlight for the place of work.

If you decide to opt for a cordless screwdriver, it would be nice to have a battery indicator. These are LEDs different colors- green, yellow, red, which are located on the body. If it is green, the charge is full; if it is red, it is almost empty.

The location of the indicator depends on the company, but is usually located on the thickening of the handle, in the same place as the backlight LED, or in the upper part of the case.

Automatic feeding of self-tapping screws

Such screwdrivers are also called store-bought. This option is useful for professionals, especially those who work with drywall, where fasteners need to be placed in small increments. Self-tapping screws are mounted on a special tape, tucked into guides, automatically fed to the holder.

This option can be implemented in two ways: there are store screwdrivers (in the photo on the left) and there are nozzles for a conventional screwdriver. For home use the second option is preferable, since the tool can work like a drill or reverse. A shop screwdriver is highly specialized equipment for professional use.

Based on the types and technical properties necessary for many species construction works tool. Having basic information about what screwdrivers are for and how they are used in everyday life or in professional activities, you will not make a mistake with your choice when buying a tool.

Where is a screwdriver used?

A screwdriver will perfectly replace a drill, drill through metal and even concrete. The moment will come when the screwdriver will almost replace the screwdrivers.
Screwdrivers are needed to:
. It is easy to tighten or unscrew various fasteners: self-tapping screws, screws, bolts.
. Drill holes in a wide variety of materials. Screwdrivers can make holes in metal, wood, drywall, brick.
But the people found other uses for screwdrivers, sometimes completely unexpected. For example, with this tool you can perfectly mix mortars and paints, as well as drill holes in the ice if you went ice fishing.

What types of screwdrivers are on the tool market

There are enough classifications of screwdrivers. Manufacturers produce household and professional tools, which, in turn, may differ in batteries, in particular, in their power, in the diameter of the cartridge, in the materials from which the gears of the gearbox are made. There are screwdrivers that have additional functions. It is clear that the price various kinds screwdrivers are also different. The price also depends on the brand.
Consider how screwdrivers differ in terms of batteries. Devices are divided into two large groups: cordless screwdrivers and electric.

Li-Ion batteries

Li-Ion batteries are extremely common and popular today. They are used in many tools, portable devices, etc. What explains such a demand for these batteries? Their advantages include:
. Three thousand battery charge cycles.
. Batteries are very lightweight and very light.
. The battery charges very quickly.
. The battery does not have a memory effect on the charge.
But the modern Li-Ion battery also has negative qualities. For example, such a battery only works for three years, which means that it must be used to the maximum during this period, otherwise it will be a pity for the money spent. Li-Ion batteries are quite expensive. Li-Ion batteries are afraid of frost, so if frost resistance is important, then it is better to choose Ni-MH batteries.
Output:
. These rechargeable batteries need to be bought if there is a constant, and not one-time work with a screwdriver.
. Fully charging and discharging is not recommended for Li-Ion batteries in order for the battery to last as long as possible (discharge - at least 15%, charge - no more than 90%).
. To calibrate the battery, it is enough to perform three charge-discharge cycles (the cycles are performed in a row).

Ni-Cd rechargeable batteries

These batteries have been used for a long time in screwdrivers and other tools. The number of charge-discharge cycles is one and a half thousand. Such rechargeable batteries serve longer than Li-Ion - five years. The use of Ni-Cd batteries allows you to use the tool when low temperatures(at frosts no more than 15 degrees). The popularity of these devices is also facilitated by the fact that their cost is the lowest for batteries.
The disadvantages of Ni-Cd batteries include:
. Charging the battery lasts quite a long time, at least an hour, or even more.
. The battery has a memory-to-charge effect.
. The Ni-Cd rechargeable battery has a significant weight.
Output:
. Since Ni-Cd batteries have a memory effect on their charge, the batteries need to be fully charged and discharged to allow them to last a long time.
. Full charging is carried out using a conventional charger.
. A full discharge can be performed using a flashlight, which is often included in many screwdriver kits.

Voltage and capacity in batteries

Batteries differ from each other in such important parameters as capacity and voltage.
The unit of capacitance is ampere times hour (Ah). The charge of the battery directly depends on its capacity. Accordingly, with an increase in capacity, the duration of work that can be performed without recharging the battery increases.
The battery voltage, the unit of which is Volt (V), determines the power of a screwdriver or any other battery-type tool. In the language of professionals, this means that it depends on the voltage, what indicators will have both soft and hard torques of a screwdriver.

Mains (electric) screwdrivers

These screwdrivers are connected to the mains and are similar to electric drills. The main difference between such a screwdriver and a drill is that it can adjust the torque.
Screwdrivers¸ that are powered by the mains are great for work at home, which is performed from time to time, and for professional builders. The screwdriver does not need to be charged, it works as needed from the network, and this is its undoubted advantage. But there is also back side network tools, created precisely by the presence electrical network: firstly, electricity is needed to work, and secondly, the wire of the tool often interferes, limiting mobility and getting underfoot.

About the chuck and gearbox in a screwdriver

The screwdriver can have either a three-jaw keyless chuck (with a tool clamping range of 1/2-13 millimeters), or a chuck that has a hex socket with a 1/4 inch shank. Larger size keyless chuck makes the screwdriver more versatile.
The tooling changes very quickly with a hex chuck, which is a great convenience if changes are made frequently. Often, in the presence of such a cartridge, drills with a hex shank are used. A combination of a conventional chuck and a hex shank is possible.
The gearbox is needed to transmit the momentum of rotation of the engine to the cartridge. The torque parameters depend on the gearbox. Reducer gears are either made of metal (usually steel) or plastic. Professional screwdrivers use only metal gears.

Power

An important technical characteristic of a screwdriver is its power, which depends on the torques (soft and hard). Torques are measured in Nm (Newtonometers). The tool is more powerful if the number of torque is greater, that is, the screwdriver can drive thicker and longer self-tapping screws or drills into hard or viscous material.
. Soft torque characterizes the maximum twisting or loosening of the screwdriver. The soft torque range is 0-350 rpm.
. An indicator of the maximum effort when drilling is a hard torque. Its range is 0-1000 (maybe much more than 1000) revolutions per minute.
The performance of a screwdriver depends on the maximum torque settings. For example, with a torque of 25-30 Nm, it is usually easy to screw a self-tapping screw up to 70 millimeters long into a tree. For self-tapping screws up to 100 millimeters in length, a torque of more than 40 Nm is required (for wood). If the screws are even longer, you first need to, as a rule, drill a hole for it in the material.

Additional features found in screwdrivers

Many brands produce screwdrivers equipped with additional features. Many arguments can be made in favor of both specialized and multifunctional tools, but usually well-known manufacturers Screwdrivers are equipped with a number of additions:
. The impact mechanism is useful if you have to work with socket heads, and also, if necessary, make a hole in brick or concrete with a drill.
. The pulsed mode (temporary torque amplification mode) will make it easier to drown the fasteners into the material, easily unscrew the stuck self-tapping screw or drill if the puncher cannot cope. In addition, the pulse mode is very important if you can not rest against the tight pressing of the screwdriver.
. The possibility of backlighting, which is a relevant addition when working in places where bad light or it doesn't exist at all. The backlight is usually placed above the battery.
. Battery charge indicators and automatons that turn off charging.
Clearly the more additional features, the more expensive the screwdriver. As you can see, there is no universal tool suitable for any task. And you should choose a screwdriver, always assuming the purposes for which it will be used.

What should be guided by when choosing a tool for work at home or in the country

Usually for home or dacha works enough network model. Its weight is small, there is no special need for mobility. When choosing a battery version, it is better to buy Ni-Cd or Ni-Mh if frequent work is not expected. If you have to work often, a modern Li-Ion battery will justify itself.
As for torque, 25-35 Nm is quite normal for home use. A more powerful screwdriver can also be taken if your financial capabilities allow.
A battery with a capacity of one and a half to two amperes per hour with occasional use at home or in the country is quite suitable for you.

What should be guided by choosing a tool for professional use

If you are going to use a screwdriver hard-to-reach places, it is better to purchase a compact model. With long and frequent continuous use of the tool, it is logical to stop at the Li-Ion battery. The maximum torque of the screwdriver must not be lower than 40 Nm. But of course, the torque can be more, depending on the type of material you will be working with (of course, drywall and brick require different torques).
Why choose Li-Ion batteries? They ensure the continuity of the workflow due to the fact that they can be quickly charged. In addition, their weight is quite small, which becomes very an important factor with prolonged use (less tired hand).
To select additional functions, you need to clearly understand the nature of the future work. If you have a hammer drill as well as a drill, you are unlikely to need all the possible additions that modern screwdrivers are equipped with. Therefore, there is no need to overpay for multifunctionality if it is not needed for the application.
There are many models of screwdrivers on the market now, so you can always find a tool that is suitable for solving your particular tasks. We hope that the article you read will help you as much as possible. good choice screwdriver.

How to choose a screwdriver, a 9-step instruction, an article from which you will learn everything about screwdrivers! Types, capacities, characteristics, application, comparisons.

We are preparing the orchestra for the working season. How to choose a screwdriver - a 9-step guide

To assemble furniture or hang a picture, today it is not necessary to make a lot of effort.

• The main thing is to choose the right tool!

This article will help you understand the variety of these tools and buy a screwdriver that is right for you.

1. Purpose of the tool

Screwdriver is only suitable for working with fasteners– the ideal assistant in assembly of furniture or simple repair work.

There are also universal tool: a drill driver that combines the first two functions - drilling and screwing.

Cordless screwdriver - acts as a screwdriver, and also allows you to unscrew and tighten the fasteners. However, its power is lower than the power of a conventional screwdriver.

2. Tool type

A classic of the genre is a hammerless drill or a screwdriver. Such a tool makes only rotational movements. A hammerless drill is ideal for working with non-hard materials and wood.

• If you need to tighten the screws or drill holes in the wall - this is a win-win option.

There are instruments with impact - in addition to rotational movements, they perform forward and backward movements. This allows you to drill more durable materials: concrete, brick and various metals.

*Impact drills are more versatile - you can always turn off the impact function and move on to work with more fragile materials.

Angle tools are required to work in confined space or hard to reach places. Here the gearbox has the shape of the letter "L" and is fixed at an angle of 90 degrees - hence the name.

Some hammerless screwdrivers also have additional angled bits. For example, it is very convenient when working under the hood of a car.

3. Cartridge type

Any screwdrivers are equipped with a chuck. This is the mechanism that holds the nozzle or drill. In screwdrivers, the chuck is installed under the bits. Bit - a small nozzle, hexagonal on one side and various shapes with another. To change the nozzle - just remove one and, until a slight click, insert another.

Another important parameter is the diameter of the cartridge. It determines what size drill or bit can be used when working with a tool. For non-professional instruments, a range of 0 to 20 mm is sufficient.

4. Tool power

The power of the tool is determined by the voltage that the battery produces. It varies from 1.2 to 36 volts.

Thus, for small jobs, you can buy a screwdriver with a voltage of 3-6 volts. For drilling in non-hard materials, a screwdriver with a voltage of 10-15 volts is suitable.

• When choosing a screwdriver, pay attention to the battery capacity - the duration of work depends on it. The average is from 1 to 3 A / h.

Often included is a second battery for continuous operation, as well as a special base for charging.

5. Maximum torque

Maximum torque - determines the efficiency of the tool.

This indicator shows how large diameter and the length of the screw will be able to tighten the screwdriver.

• Power, voltage and maximum torque are interrelated indicators. The higher the voltage, the higher the torque.

For a screwdriver, the maximum torque can be several N / m. This is quite enough to assemble a chair or bracket.

Screwdriver with a torque of 10-30 N/m – to cope with any task. Tighten the screw firmly metal shelving- no problem!

*Torque of 30-40 N / M - will easily allow you to drill a tree.

A device with a maximum torque of 40 N / m and more - easily cope with brick concrete and metal surfaces

6. Number of speeds

As a rule, screwdrivers and screwdrivers have only one speed: from 0 to 800 rpm - this is enough to work with fasteners.

But most drills have 2 speeds:

1st mode with a number of revolutions from 0-400 rpm - mainly used for twisting.

2nd mode with the number of revolutions from 400-1300 rpm - for drilling holes.

• Almost all screwdrivers are equipped with a "reverse" function - for unscrewing fasteners.

7. Additional information

When working with such tools, reliability and safety are important.

Many models have: power button lock; battery protection system against overload, overheating and deep discharge; backlight working area built-in LED flashlight.

When choosing a tool, pay attention to its weight - the higher the power of the screwdriver, the heavier it is.

8. Equipment

As a rule, a set of screwdrivers comes with: a compact plastic or metal case, a battery charger, but sets of drills and nozzles are bought separately, most often.

• Do not forget that when working with screwdrivers and drills, you need to protect your eyes - use construction goggles.

9. Recipes

If you need a tool for simple work, a small and light screwdriver with a voltage of 3 to 15 volts, with a built-in battery, with a keyless chuck or a padded one, will suit you.

For some types of work, it makes sense to buy an angle-type screwdriver - especially if you often repair the car.

If you use tools at home and occasionally: it is worth buying a screwdriver-drill - unstressed or impact, with a voltage of 15 volts and a torque of 30 N / m, or better - with power support and from the mains.

Is there a major overhaul ahead?

An impact drill with a voltage of 20 volts or more, with a quick-clamping or screw-in chuck for large drills, with a torque of 40 N / m and 2 speeds for different modes works.

Each instrument has its own special sound! Do you have a whole orchestra?

How to choose a screwdriver - video

Every person at least once in his life has dealt with such a tool as a screwdriver. Everyone has ever twisted bolts, screws or self-tapping screws.

Sometimes, if a screw needed to be driven into a hard surface, or there were a lot of these screws, such twisting became quite difficult. To facilitate such "twisting" processes, a special device was created - a screwdriver. We will talk about how to choose a good screwdriver for the home in this article.

Screwdriver (screwdriver)

Special electric manual tool, designed for tightening, as well as loosening self-tapping screws, screws and other screw fasteners, is its main function.

Some electrical drills can also act as a screwdriver, but for them this function is not the main one. A drill can be used for such purposes from time to time and with small amounts of work, and in all other cases it is better to use a screwdriver.

The main technical characteristics of screwdrivers, which determine their capabilities, are as follows:

1. Maximum torque.

By physical definition twisting Moment is the amount of rotational force acting on a body. That is, it is the force with which the working element of the tool rotates. Torque determines the diameter and length of the screws you can drive, as well as the hardness of the material you can work with.

Torque is measured in newton meters. In household screwdrivers, the average torque is from 10 to 30 N / m. This is enough to cope with most of the necessary tasks. A professional screwdriver may have a torque of 100 N/m or more.

Screwdrivers with high torque can be used for driving screws in very hard materials and even for drilling as drills. A very important feature good screwdriver is the ability to adjust the torque, which allows you to twist different screws with different strengths.

Manual household screwdriver2. Rotational speed.

The rotation speed indicates the number of revolutions of the working nozzle per unit of time. This indicator helps to determine at what speed you can unscrew or twist something.

It should be noted that for normal operation with screws and with self-tapping screws, a speed of 450-550 rpm or even less is enough. If a screwdriver is used for drilling, then this requires a speed of 1000 rpm. These are relatively small indicators of rotation speed, so, for example, in a grinder, the rotation speed can reach 11,000 rpm.

The speed of rotation, as well as the torque, can be adjusted using a special screwdriver speed controller, the presence of which is also a positively necessary factor.

3. Characteristics of the battery.

If the screwdriver does not use an electrical network (mains screwdriver), but an internal battery, then this is a cordless screwdriver. From characteristics battery the duration of the tool and many other parameters will depend. When buying a screwdriver, you should pay attention to the type, capacity and voltage of the battery.

There are the following main types of screwdriver batteries: lithium-ion, nickel-cadmium and nickel-metal hydride batteries. Most household models of screwdrivers are equipped with nickel-cadmium batteries. Such batteries have a limited number of charge-discharge modes and the so-called "memory effect", so they need to be charged to the end and discharged too.

More expensive instruments have lithium-ion batteries that do not have a “memory effect” and can be recharged without waiting for a complete discharge. Nickel-metal hydride batteries for screwdrivers are no longer relevant.

Battery capacity screwdriver measured in amps/hours. The capacity depends on the time during which the tool can work without recharging. The larger this capacity, the better. On average for domestic use you can take screwdrivers with a battery capacity of 1.2 A / h.

Battery voltage screwdriver defines electrical power, and hence productivity. Measured voltage in Volts. A more powerful screwdriver makes the job easier.

When choosing a household screwdriver, be guided by the battery voltage of 12-14 V.

When buying a cordless screwdriver, also pay attention to the presence of a charger in the kit. Charger for the battery of a screwdriver, it acts by analogy with chargers for mobile phones.

4. Cartridge type.

As with a drill, screwdrivers can have keyless or key chucks. Because in screwdrivers loads different from the loads in the drill, then the best choice there will be a keyless chuck for them, which allows you to change nozzles more quickly.

5. Additional features.

TO additional features, which help to make the use of a manual screwdriver more convenient and efficient, include the following:

The presence of a reverse. Reverse is rotation patron in the opposite direction. The reverse function can even be attributed to the main ones, since it is thanks to it that it is possible to unscrew something;

Spindle lock. The lock makes it easier to change the screwdriver bits in the chuck;

Backlight. With the help of a small flashlight screwdriver can illuminate work surface, such a screwdriver with a flashlight can be used in unlit rooms or in conditions of poor visibility on the street.

Some manufacturers of screwdrivers add a special case to the kit, in which it is very convenient to carry and store the tool, as well as a special holster. Therefore, when choosing a screwdriver, look for the presence of such a suitcase, a holster for screwdriver would also be an added bonus. I hope these tips will help you learn how to choose the right screwdriver.

Screwdriver torque is a significant parameter that you need to pay attention to when choosing. It must be taken into account whether the tool will be used for homework or professional. On sale today there are various models that differ in their characteristics.

There are many models of screwdrivers from various manufacturers on the construction market, which differ depending on the power source, parts and functions.

Screwdriver models

A screwdriver is the most commonly used tool, which is indispensable for construction and repair activities. Today, manufacturers offer a variety of models that can be used for various conditions. This tool is useful for handmade, it is necessary for tightening / unscrewing screws, screws, self-tapping screws, for drilling and even for stirring building mixtures.

According to the power source, the tool is classified into:

The cordless screwdriver is powered by the battery included in the kit.

1. Rechargeable models powered by special batteries. They increase the weight of the tool, but make it easier to work in hard-to-reach places.
2. Network devices that require connection to the electrical network. They have a limited reach due to the length of the cord, although extensions can be used.

According to the purpose, the equipment can be divided into:

• models for construction/repair work;
• for production shops, workshops, auto repair shops;
• for industrial enterprises;
• for domestic use.

There are professional, semi-professional, household models on sale. When choosing, attention should be paid to the torque, which shows what kind of work the screwdriver can handle.

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What is meant by torque?

Torque is a value that allows you to determine the level of load on the equipment. Which option to choose? It is usually equal to 5-10 Nm, this is quite enough for the safe and high-quality operation of the tool. This parameter is provided for most household and semi-professional models that can easily cope with tight self-tapping screws, drilling steel, concrete.

What should be the torque? You should pay attention to what the instrument will be. For example, for universal device rather high torque values ​​​​must be chosen so that the tool copes equally well with any type of work, be it self-tapping screws or structurally rigid materials. If you need a tool only for drilling wood, then you can prefer a model with a small moment from among the household ones. When choosing, pay attention to the number of revolutions. For example, 400-500 is enough for screwing screws. For drilling hard surfaces, it is best to use devices with a speed of 1200-1300 per minute.

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Torque to screw diameter ratio

When choosing a cordless or corded screwdriver, it is important to correctly determine the ratio of the screw diameter and speed. Such a dependence is not too difficult to determine:

To tighten screws of different diameters, different rotation speeds are required.

1. If the screw diameter is 6 mm, then the rotational speed during screwing will be 10 Nm. For structurally soft or hard materials, the frequency will be 25 Nm.
2. If the screw diameter is 7 mm, then the torque when working with hard materials will be 27 Nm, and for soft materials– 11 Nm.
3. With a maximum screw diameter of 8 mm, the torque will be 30 Nm.

What does this ratio show? It is possible to determine exactly what torque can be used for a certain working screw diameter. Right choice will not only make the work more efficient, but also improve the quality, reliability, and durability of the equipment. The operation will be completed much faster, the operator will spend less effort.

At network equipment high power has little effect on the work process, and the batteries run out quickly. Therefore, it is necessary to have spare batteries and the ability to charge those already planted. Usually for professional tool manufacturers provide spare batteries, but for more simple models at least one battery will have to be purchased separately. When choosing a screwdriver, it is necessary to take into account the presence of another function - reverse. It is necessary in the event that the drill is stuck in the material. Such a reverse is usually electronic; to control it, you should use a two-position switch, which is located near the start button.

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Which torque is better?

A screwdriver is a tool that is necessary for carrying out various kinds of work. This is not only construction, but also many home repair work, for example, assembling furniture, installing communications. To choose the right equipment, you should pay attention to the torque, which affects the comfort and quality of work. For example, to assemble furniture, too powerful a tool is not needed. If you plan to install interior partition, then you need to take more professional equipment that will perfectly cope with the task.

Drills and screwdrivers are used for mixing building mixtures, you just need to purchase a construction mixer nozzle.

The torque of such tools must be sufficient to be able to mix even the most viscous mixtures and solutions, to ensure their uniformity and high quality.

For mixing concrete and other viscous mixtures, special nozzles are used.

If you want to use nozzles for mortars, then the torque must be sufficient to cope with mixtures of not only low viscosity, but also high. The choice of model depends on the planned work. If a screwdriver is required to be used for mixing liquid mixtures, then the torque may not be too high. If the tool is purchased to work with viscous mixtures, then it is already necessary to prefer professional fixtures, the speed of which is high.

Equipment that will be used for a variety of jobs must have a speed controller. Then the torque can be changed depending on what kind of work needs to be done. When choosing a screwdriver, you need to make sure that the lock for the control button always works, and not only at maximum effort. In the first case, the tool can be used for any work with the most convenient conditions. The torque value can be changed. It is recommended to buy models that have manual or electronic control. They have a special step-down transformer that works great with liquid mixtures when the voltage goes down.