Choosing 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. To begin with, we decide whether it is household or professional model needed. If you are buying 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 expected 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 motor voltages from 7.2V to 24V (Volts). The higher the voltage, the less current is needed to obtain required power. Accordingly, it is easier to obtain more power in a screwdriver with an 18V motor rather than a 12V or 7.2V motor. It is worth clarifying that the most popular screwdrivers have 12V, 14V and 18V motors.
Torque screwdriver. Torque is measured in Nm (Newton per meter). In simple words Torque is the force with which your screwdriver screws in the screws. The greater the torque, the more possibilities the screwdriver has. In modern household screwdrivers, the torque is usually 10-28 Nm. This is quite enough for housework. With a torque of 28-30 Nm, the screwdriver can screw in 100 mm self-tapping screws and drill wood and 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 torque reaches 70-140 Nm.
Most screwdrivers have a function torque adjustment. It is used where greater control is required during execution. certain works. Adjustment occurs by switching the ring located on the screwdriver body, at the base of the chuck. On the ring there are numbers indicating modes in setting the torque. Drill icon after maximum number The ring shows the drilling mode.
Using the example of tightening screws, the function is used like this:
Tightening the screws different lengths You don't need just one torque. For smaller screws, a lower tightening force is sufficient, and for longer screws, a correspondingly higher tightening force is sufficient. Most likely, everyone who screwed a self-tapping screw into wood at least once, but buried it in the material. And where it is necessary for the surface to be flat 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 tightening the screw. Thus allowing more precise control of the work 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) - these 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 (Ampere hour). A screwdriver with a capacity of 2.0A/h, under the same conditions, can work longer than a screwdriver with a battery capacity of 1.2A/h. A capacity of 1.2-1.5A/h is enough for home use. And given the current battery charging time of 1 hour, you will always have a “fresh” battery at hand. Of the minuses: they require complete discharge.
NiMh(nickel-metal hydride) - these batteries are more expensive, but their capacity is also higher, from 1.5 to 2.6 A/h. Suitable for both home use and more complex and long-term use. Does not require complete discharge.
Li-Ion(lithium-ion) batteries are the most expensive and have a high capacity, which can be above 3.0A/h. Another advantage of Li-Ion batteries is their light weight. The difference in weight can reach 40%. Li-Ion batteries do not have a memory effect, which means you don’t have to wait until the battery is completely discharged.
It is worth saying that the warranty does not cover batteries, since they often fail due to the fault of the buyer. If you leave the battery at a low temperature even overnight, such batteries may no longer be usable. Store batteries in a warm place.
Speed screwdriver. For different types works require different speeds. For drilling, higher speeds of 1000-1300 rpm are needed. To tighten screws, 400-550 rpm is enough. Screwdrivers come in single-speed, two-speed and three-speed types. Switching speeds allows you to work with the speed you need to solve various problems.
So. If you are choosing a screwdriver for your home, then a 12-14V screwdriver with a battery capacity of 1.2-1.5A/h and a torque of 15-26Nm is suitable. This screwdriver can handle almost any job around the house. Household screwdrivers with these characteristics cost 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, warranty conditions, quantity. Well, the screwdriver itself should be held in your hand, turned, pressed, etc.
Based on the types and technical properties this is necessary for many species construction work tool. Having basic information about what screwdrivers are for and how they are used in everyday life or in professional activity, you can't go wrong with your choice when buying a tool.
Where is a screwdriver used?
A screwdriver will perfectly replace a drill and will drill through metal and even concrete. The moment is about to come when the screwdriver will practically replace 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 be used to make holes in metal, wood, drywall, and brick.
But people have found other uses for screwdrivers, sometimes completely unexpected. For example, this tool can perfectly stir mortars and paints, as well as drill holes in the ice if you go ice fishing.
What types of screwdrivers are available 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 types screwdrivers are also different. The price also depends on the brand.
Let's look at how screwdrivers differ in terms of batteries. The devices are divided into two large groups: cordless and electric screwdrivers.
Li-Ion batteries
Li-Ion batteries are extremely common and popular today. They are used in many instruments, portable devices, etc. What explains such demand for these batteries? Their advantages include:
. Three thousand battery charge cycles.
. The batteries have very little weight, they are very light.
. The battery charges very quickly.
. The battery does not have a memory effect on charging.
But the modern Li-Ion battery also has negative qualities. For example, such a battery only lasts for three years, which means that it needs to 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, it is better to choose Ni-MH battery s.
Conclusion:
. These batteries need to be purchased if you are going to work with a screwdriver on a regular basis rather than just once.
. Li-Ion batteries are not recommended to be fully charged and discharged 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 batteries last 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 rechargeable batteries.
The disadvantages of Ni-Cd batteries include:
. Charging the battery takes quite a long time, at least an hour, or even more.
. The battery has a memory effect on its charge.
. The Ni-Cd battery has a significant weight.
Conclusion:
. Because Ni-Cd batteries have a charge memory effect, the batteries need to be fully charged and discharged to ensure they last a long time.
. Full charging is accomplished using a conventional charger.
. A full discharge can be performed using a flashlight, which is often included in many screwdriver kits.
Battery voltage and capacity
Batteries differ from each other in the following ways: important parameters, like capacitance and voltage.
The unit of measurement for capacity is ampere times hour (Ah). The battery charge directly depends on its capacity. Accordingly, with increasing capacity, the duration of work that can be performed without recharging the battery increases.
The battery voltage, the unit of measurement 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 the voltage determines what indicators both soft and hard torques of a screwdriver will have.
Corded (electric) screwdrivers
These screwdrivers are connected to the electrical network and are similar to electric drills. The main difference between such a screwdriver and a drill is that the torque can be adjusted.
Screwdrivers¸ that operate from the mains are great for both occasional work at home and for professional builders. The screwdriver does not need charging; it works as long as needed from the mains, and this is its undoubted advantage. But there is also back side network tools, created precisely by the presence electrical network: firstly, you need electricity to work, and secondly, the tool’s wire often gets in the way, limiting mobility and getting underfoot.
About the chuck and gearbox in a screwdriver
The screwdriver can have either a quick-release three-jaw chuck (with a clamping range of 1/2-13 millimeters) or a chuck with a hex socket with a 1/4-inch shank. Larger size keyless chuck makes the screwdriver more versatile.
The equipment can be changed very quickly with a hex chuck, and this is a great convenience if replacement is done frequently. Often, if such a chuck is available, drills with a hexagonal shank are used. A combination of a conventional chuck and a hex shank is possible.
The gearbox is needed to transmit the rotational impulse of the engine to the chuck. The torque parameters depend on the gearbox. Gearbox gears are made of either 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 torque (soft and hard). Torques are measured in Nm (newtonometers). The tool is more powerful if the torque number is higher, that is, the screwdriver can drive thicker and longer screws or drills into hard or viscous material.
. Soft torque characterizes the maximum tightening or unscrewing of a screwdriver. The soft torque range is 0-350 rpm.
. An indicator of the maximum force when drilling is the 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 parameters. For example, with a torque of 25-30 Nm, it is usually easy to screw a self-tapping screw up to 70 millimeters in length into wood. For self-tapping screws up to 100 millimeters in length, a torque above 40 Nm is required (for wood). If the screws are even longer, you first need, as a rule, to drill a hole for it in the material.
Additional functions found in screwdrivers
Many brands produce screwdrivers equipped with additional functions. Many arguments can be made in favor of both specialized and multifunctional tools, but usually famous 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 you need to make a hole in brick or concrete with a drill.
. The pulse mode (mode of temporary torque enhancement) will make it easier to sink fasteners into the material, and to easily unscrew a stuck screw or drill if the hammer drill cannot cope. In addition, the pulse mode is very important if you cannot rest against pressing the screwdriver tightly.
. Possibility of illumination, which is a relevant addition when working in places where there is poor lighting or no lighting at all. The backlight is usually located above the battery.
. Battery charge indicators and automatic charging switches.
Clearly, the more additional features, the more expensive the screwdriver. As you can see, there is no universal tool suitable for every task. And you should choose a screwdriver, be sure to assume the purposes for which it will be used.
What should you consider when choosing a tool for work at home or in the country?
Usually for home or dacha work the network model is sufficient. 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 pay off.
As for torque, 25-35 Nm is quite normal for home use. You can also take a more powerful screwdriver if your financial capabilities allow it.
A battery with a capacity of one and a half to two amperes per hour is quite suitable for you when used periodically at home or in the country.
What to consider when choosing a tool for professional use
If you are going to use a screwdriver in 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 choose a Li-Ion battery. The maximum torque of the screwdriver should not be lower than 40 Nm. But, of course, the torque can be greater, this is determined by the type of material you will be working with (it is clear that drywall and brick require different torques).
Why choose Li-Ion batteries? They ensure uninterrupted work flow because they can be charged quickly. In addition, their weight is very small, which becomes very important factor with prolonged use (the hand will get less tired).
To select additional functions, you need to clearly understand the character future work. If you have a hammer drill as well as a drill, you are unlikely to need all the possible add-ons that come with modern screwdrivers. Therefore, there is no need to overpay for multifunctionality if it is not needed for the application.
There are now many models of screwdrivers on the market, so you can always find a tool suitable for solving your specific problems. We hope that the article you read will help you make the best choice of a screwdriver.
The scope of application of a screwdriver is very large, because it universal tool. For example, dismantling a lock, attaching a plinth or bookshelf, drill a hole in wood or stone. A similar tool to a screwdriver is a drill. Due to the lack of reverse and speed control, a screwdriver is chosen. Let's talk about how to choose a tool that best meets your requirements.
When choosing, you should pay attention to only three parameters: manufacturer, power and battery type. Because the device and principle of operation of a screwdriver are the same for everyone.
Manufacturer selection
There is no point in focusing your attention on a specific manufacturer. All manufacturers have a quality control system. Large manufacturers They spend a lot of money on advertising, their screwdrivers are high quality, but sometimes unreasonably more expensive than their analogues. Small manufacturers spend less money on advertising, but quality does not suffer from this. Conclusion - it is not necessary to chase a famous brand if your budget is tight.
Let's highlight three types of cordless screwdrivers: Lithium-ion (Li-Ion), Nickel-metal hydride (Ni-Mh), Nickel-cadmium (Ni-Cd) and network, below we will analyze each in more detail.
Power
Torque is the force applied by a screwdriver for tightening/drilling (measured in Newton meter, then N*m). This parameter determines the length and thickness of the screw that can be tightened, and when drilling, the maximum diameter of the hole in hard materials. IN household use, use a screwdriver with a torque of 10-20 N*m, for more serious work from 25 to 50 N*m. The maximum torque in such tools can reach 130 N*m. Screwdriver speed - if you are going to drill, it is worth looking at the rotation speed parameter from 1200 to 1500 rpm. To tighten screws, 400-550 rpm is required. The screwdriver can have two operating speeds, this choice is universal.Battery type
Li-Ion batteries.
The most commonly used type of battery today is Lithium-Ion (Li-Ion). It has three thousand charge-discharge cycles.
Pros:
- Light weight;
- Fast charging;
- High capacity;
- Not subject to charge memory.
- The most high price of all types;
- Does not like negative temperatures.
If we talk about a 10.8 V battery, it uses three of these cells. At 14.4 – four. At five. If we are talking about use at home, then under no circumstances store long time in a discharged state this battery. Otherwise, you will have to buy a new one, and they are not cheap.
Voltage(unit of Volt V). This indicator affects the power that can be obtained from a screwdriver. In simple terms, voltage directly affects maximum performance. In practice, this indicator is not so important, for example, if you take two screwdrivers that produce 25 Nm, one is powered by a battery with a capacity of 14.4 V, and the other by 18 V, then you will not see much difference in operation, and the latter will not work much longer .
If you don’t need a cordless screwdriver and your budget is very limited, a corded one will suit you. Their choice consists of determining the torque. 
Corded screwdriver It will be useful both for one-time work at home and for professional use in repairs and construction. But here, there are both pros and cons.
The advantages include:
- Does not require charging;
- The power is always at the same level and does not depend on the battery.
- Dangling wires underfoot when other devices are connected;
- Attachment to the outlet site.
- One of the features of the screwdriver is cartridge type. There are both quick-clamping (single-clutch and double-clutch) and cam. Clamping diameter from 0.5 to 13 mm.
You can easily install the equipment in the quick-release single-socket chuck even with one hand. In the case of double couplings, you will have to hold the shaft with one hand and tighten it with the other.
For cams, a special key is also required. This is not always convenient if you need to quickly change equipment.
- Presence of impact mechanism useful if, when tightening a screw, resistance increases and the screwdriver tightens with a higher torque. When drilling stone or concrete, it prevents the drill from getting stuck. 
- Presence of impulse, temporarily increases torque. Suitable for smoothly screwing fasteners into materials, unscrewing stuck fasteners or drills, and saves slots on screws. Does not require tight pressing of the tool, which affects the smoothness of the work. When drilling, it also prevents the drill from getting stuck in the material.
- Availability of 3 operating speeds, allows you to abandon the drill at home, since you can always increase the number of revolutions, thereby screwing in the screws “with a whistle,” and the first speed always gives decent torque.
- The presence of backlight, this function is very useful in low light conditions. It happens that while working you don’t notice how evening has come and it’s quickly getting dark. There's not much time left to work, but it's hard to see. This is where the built-in flashlight comes in handy to finish the job without being distracted by searching for additional light sources.
- Battery charge indicator, some models have an indicator (located on the battery) showing the charge level. This feature is not required, but its presence will help determine how long the screwdriver will last. 
- Adjustment ring– when the screw is fully tightened, the chuck stops rotating. Thus, the fasteners do not sink into the material and the equipment is not damaged.
Ergonomics and equipment.
For convenient use of the tool, some manufacturers cover the surface of the screwdriver with rubber pads. The screwdriver does not slip in your hand. If you put it on a slippery surface, it won't go anywhere. The presence of a hook on the handle allows you to hang the screwdriver when not needed. In some models, the handle has a bit holder, protection against accidental activation.
The tool is usually sold in a plastic case or bag for storage and transportation. More expensive models are equipped with a set of bits and a second battery. If possible, be sure to hold/twist the screwdriver in your hand before purchasing, since it is up to you to work with this tool. 
Summarizing
- A screwdriver for home/dacha: a corded one is quite enough. It is more affordable, lightweight, and an outlet is always nearby. But if you want a cordless screwdriver, then you should choose Ni-Cd and Ni-Mh. If you use it infrequently, the battery will last much longer.In such cases, when regular use is necessary, not a day without downtime, the availability Li-Ion battery will work out the investment 100%. The lifespan of a Li-Ion battery is shorter, but in this case, letting him sit idle is a waste of money.
For home use, a torque of 10-20 N*m will be quite enough. If a wider range of work is planned and finances allow, then 25-35 N*m. A capacity of 1.5-2 Ah is enough for all occasions.
Screwdriver for professional use: how to work is not always necessary convenient places, it would be better to choose a smaller device. A Li-Ion screwdriver with a high torque of 35 N*m and above, depending on the type of material, would be a justified purchase.
Repair is a permanent condition, and a screwdriver will be a good and necessary assistant. There are also almost everyday tasks in which the help of modern technology is useful. For example, how often do you tighten or remove screws? I think quite often. Buy a screwdriver, you will do it even more often, but faster, easier and with better quality.
And if you want to attach decorations and paintings to the wall yourself or its elements (shelves, whatnots), it will not be easy without a screwdriver. Try, for example, without precise (down to the millimeter) drawings to assemble and fit the parts of a multi-level bookcase, folding sofa, while alternately tightening and unscrewing the screws, transferring them to a new place. Of course, as they say, measure seven times... But help convenient tool It won't hurt you anyway. And there will be no damaged screws or additional calluses.
In other words, screwdrivers are designed for tightening screws and self-tapping screws without preliminary preparation holes. They allow you to save energy, quickly and easily perform labor-intensive tasks. handmade, improve its quality. - This is one of the three important tasks of a man. And, having built it, equip it with beautiful and comfortable furniture, decorate with paintings and fence with an attractive picket fence. A screwdriver will be your reliable assistant in everything.
Design and principle of operation of a screwdriver
The principle of operation of a screwdriver is the same as that of a drill, but there is a difference - a torque limiter. Directly behind the chuck, the screwdriver has an adjustment ring that allows you to set the required torque: as soon as the screw is tightened, the chuck stops. although the engine continues to run. This prevents the slot on the screw from breaking off, “sinking” into the depth of the surface and wear on the screwdriver bit. The number of adjustment steps usually ranges from 5-7 to 22, and if the screwdriver can work as a drill, then there is also a special provision - “without limitation”, i.e. all the torque is transmitted to the drill. It is the stopper that determines how accurately you screw the screw and whether its head will remain on the surface.
This tool will help you secure many small but necessary interior details; it simply never tires.
What about the drill?
In principle, you can also tighten screws. Nowadays they often do just that, but a lot depends on the hands of the master: by first setting the drill torque to a small position, you can control the accuracy of the process and not deviate from the markings. Once adjusted, you can determine the required speed to continue working. In this case, the drill must have smooth speed control and an upper limiter. But it's rude anyway. Let's just say it's unprofessional. This approach is suitable for rough installation work. You can do everything beautifully and clearly, easily and conveniently only with a screwdriver, and it is still advisable to make a preliminary hole with a drill, and only then screw the self-tapping screw into it, but this, of course, depends on the material into which the self-tapping screw is screwed.
What kind of screwdriver do you need for your home?
Like all tools, screwdrivers can be professional or amateur. As has already been written many times, professional ones are designed for long-term, without interruptions, permanent job and have a greater resource, are made from more expensive materials and, naturally, they cost more. A amateur instruments involve a smaller scope of work, a smaller resource and a lower price.
Family contract - modern screwdrivers will be obedient and useful even in graceful female hands
Often people are on the hunt for a tool with a serviceable motor to extend its life. But a good amateur screwdriver, even with a maintenance-free motor, has a service life of at least 150 hours of pure operation, and there are tools that have a service life of 1,500 hours. How much it will be in thousands of tightened screws is not difficult to calculate. There are corded screwdrivers, these are professional and very powerful tools. But cordless screwdrivers are more often found on sale, and these are the tools that are offered for home users.
Furniture assembly is the main use of screwdrivers. No matter how many screws there are, you will tighten them quickly and efficiently
What's good about a cordless screwdriver?
It is safer and more mobile (the wire does not get in the way, and you can easily work, for example, on a ladder). A cordless screwdriver is indispensable in the country and just on the street. , more ergonomic, lighter, which means that when working with it, you will get much less tired.
Which screwdriver battery is better?
Theoretically, a nickel metal hydride (Ni-MH) battery is better. For environmental reasons, the whole of Europe is switching to such batteries, since nickel-cadmium batteries(Ni-Cd) contain cadmium, which is considered an allergen. But our choice is still limited, and Ni-Cd batteries are the most common. By the way, they have their pros and cons. Ni-MH batteries have smaller dimensions, but are less able to withstand high currents, and it is better not to use a tool with a Ni-Cd battery in conditions negative temperatures. Finally, Ni-MH batteries have a higher capacity, but also a higher price.
An important point is the battery capacity. The larger it is, the longer it will not need to be charged. Many models often have two batteries: you use one and charge the other. With this configuration, the difference of 0.5 Ah may not be noticed.
And the main disadvantage of household models compared to professional ones is that charging usually takes 1-2 hours, and few models can boast of a half-hour charge.
Due to their size, very small household models are very convenient when working in corners and other hard-to-reach places
Screwdriver torque and speed
We have already talked about the limiter, but now we will clarify what numerical parameters you should look at when choosing a screwdriver. For screwdrivers, the torque is most often limited at 5-10 Nm. This is enough to tighten the most “serious” screws, and the engine does not suffer from overloads. Impressive numbers in front of the letters Nm (there are models up to 30 Nm) are useful when screwing screws into hard materials, such as steel, hardwood - beech, hornbeam, oak, and also when using a screwdriver as a drill - for drilling holes large diameter. But do not forget that the maximum drilling diameter of screwdrivers is still limited, therefore the drilling function is only auxiliary.
In general, screwdrivers with high torque can be called universal: they are equally convenient for tightening screws and drilling any materials. Less “strong” screwdrivers are best used only for assembly work.
Much more important is how the engine performs under load, whether it holds speed well and whether it produces enough power when the battery is discharged. True, this can only be determined experimentally. Another serious indicator is maximum speed. To tighten screws, 500 rpm is enough, but for drilling you need 1200-1300 rpm. An even higher rotation speed is needed only for specific tasks.
By the way, modern models supplied powerful system cooling with increased air flow, which protects the tool from overheating at low speeds.
Powerful models of screwdrivers can handle a large volume of work, for example, installing the roof of a house or ceiling parts
Choosing a screwdriver and proper care of it
When choosing models, it is necessary to compare their main specifications: rated power, speed idle move, maximum diameter of screws, maximum drilling diameter in steel and wood, torque, weight - assessing all this from the standpoint of practical necessity. And of course, the decision to choose a specific screwdriver model should be influenced by the quality of the tools, the level of service and maintenance time, the price/performance ratio of power tools and spare parts.
The construction market now has enough wide choose drills and screwdrivers from various manufacturers. The differences between models from different companies are manifested mainly in the ease and convenience of working with them, the availability additional functions and configurations.
And in conclusion, it is worth adding the following: like any power tool, screwdrivers require careful attitude, the right conditions storage and operation (dry place, no direct contact with sun rays, temperature range from 10 to 25°C). Leaving a screwdriver idle for a long time, especially when discharged, is harmful to its battery, so periodically give it at least some work. Alternatively, disconnect the battery during storage. And batteries with a “memory effect” will have to be “dried” before use, that is, the charging/discharging cycle will have to be repeated several times.
When purchasing a screwdriver or hammer drill, you need to pay attention to many criteria. You can purchase a regular household tool that is suitable for minor repairs, but you can also choose a professional or universal one, which has more power. When choosing, you need to pay attention to what maximum torque a screwdriver or hammer drill is provided for, otherwise the tool can be broken in the first hour of fruitful work.
Screwdriver speed
The maximum torque of a screwdriver is a value that indicates the load level. For professional and household devices it is different. But most often it is 5-10 Nm (Newton per m), which is quite enough for high-quality, safe work screwdriver. This is enough to ensure work even with very tight screws when drilling such surfaces as concrete or steel, when creating holes with large diameters.
What should be the maximum torque of a screwdriver? If you need a universal screwdriver, then the torque must be selected quite high so that with the help of the device you can not only screw in self-tapping screws, but also drill holes with a different diameter from each other.
If you choose a drill whose torque is low, you must remember that it can only be used for working with soft structural materials, such as wood.
If you plan to use a screwdriver for drilling hard materials, then it is best to choose a device with a high rotation speed.
The rotation speed also has great importance, usually for screwing self-tapping screws it is enough to buy a drill with a speed of 400-500 revolutions per minute. But if you need to carry out other operations, then it is best to take equipment whose rotation speed will be about 1200-1300 revolutions per minute. But such high speeds are usually only necessary when performing professional work.
Return to contents
Device screw diameter ratio
Let's consider the relationship between the rotation speed of the drill and the diameter of the screw used in the device:
- with a maximum screw diameter of 6 mm, the rotation speed when screwing is 10 Nm for structural soft materials and 25 Nm for structural hard materials;
- with a maximum screw diameter of 7 mm, the rotation speed to interact with soft materials is 11 Nm, and for working with hard materials - 27 Nm;
- with a maximum screw diameter of 8 mm, the torque of the drill when interacting with soft structural materials is 15 Nm, and with hard ones when screwing - 30 Nm.
The ratios show how it is possible to use working screws of the required size at a certain torque. This makes the work more efficient, but it must be remembered that when using screws with a small diameter, the duration of the operation increases. There are some peculiarities when working with large-diameter screws: the batteries of such equipment run out quite quickly. Therefore, choose models where the battery has more power, if you want your power tool to work as long as possible without tiring recharging, or purchase a kit with a spare battery.
There's another one most useful characteristic- reverse motion. This function allows you not only to free a suddenly stuck drill, but also to quickly unscrew a tight self-tapping screw. Reverse (reverse) for most is electronic: switching is carried out by changing the so-called electrical polarity. To control the reverse, a two-position switch is provided; it is located next to the tool start button.
Return to contents
Rotary hammer torque
A hammer drill is a tool that is used in various construction and repair work as often as a screwdriver. It can be used not only as impact equipment for dismantling walls and partitions, but also when making holes for hard, complex structural materials, as a convenient mixer that allows you to quickly and correctly mix any building mixtures.
The torque of the hammer drill is transmitted from the engine to the spindle or shaft, and with the help of a special nozzle, the solution begins to mix. To do everything efficiently, you need to correctly select the maximum torque of the hammer drill. The fact is that the device can work with various media: not only low-viscosity, but also highly viscous. In the first case, the torque of the hammer drill may not be as high as the speed. It is better to choose equipment that has the ability to regulate speed.
For most models, the lock for the control button can only be activated when the force is maximum, but this is not always enough for operation. Therefore, it is recommended to take models that have electronic or manual control. When interacting with low-viscosity media, you can also use a step-down transformer, but it should be remembered that as the voltage decreases, the torque decreases.
When interacting with highly viscous mixtures, it is necessary to use a perforator whose power is high enough for accurate and proper mixing. In this case, the maximum torque of the hammer drill is high value(as a rule, these are professional devices).
You can use the tool with high power, the torque of which is high, and equipment with a built-in mechanical gearbox, which allows you to work even at first speed. The engine must be provided with cooling so that it does not overheat during the process. When choosing equipment, you need to pay attention to what operations will be carried out and what power will be optimal.
When choosing a screwdriver or hammer drill, you need to pay attention to many parameters, including torque. It is this value that often determines which tool you choose: an ordinary household one, which is enough for screwing a small number of bolts and other things, or a professional one, designed for long-term, effective work.