Is a screwdriver a portable power tool. Cordless drill driver. Incorrect battery selection
Description of the equipment: ............................................... ................. 3
Model Specifications.................................................................... 4
Scope of delivery: ............................................................... ................. 4
Delivery set:
1. Cordless drill
2. Battery
3. Charger
4. A set of bits
5. Instructions for use and maintenance
Safety regulations.
Attention! Power tools are hazardous equipment. When using power tools, to avoid the risk of electric shock, injury, or fire, STRICTLY follow these basic safety precautions. Read and remember these instructions before operating the power tool. Keep the safety instructions in a safe place.
SAVE THESE INSTRUCTIONS
Workplace
Contain workplace clean and well lit.
Cluttered, poorly lit workplaces are a cause of injury.
Do not use power tools in explosive environments such as where flammable liquids, gases, or dust are present. Power tools create sparks that can ignite dust or steam.
Keep children and visitors a safe distance from operating power tools.
Avoid distractions - this can cause you to lose control of your work and cause injury.
electrical safety
Before switching on, check whether the supply voltage of your power tool matches the mains voltage; check the serviceability of the cable, plug and socket; in case of failure of these parts, further operation is prohibited.
Double insulated power tools do not need to be connected to an outlet with a third ground wire. Power tools without double insulation must be connected to a grounded socket
Avoid body contact with grounded surfaces such as pipes, radiators, stoves, and refrigerators. The risk of electric shock increases dramatically if your body comes into contact with a grounded object. If the use of a power tool in wet places is unavoidable, the current to the power tool must be supplied through a special breaker device that turns off the power tool in the event of a leak. Electrician's rubber gloves and safety shoes will further enhance your personal safety.
Do not expose power tools to rain or wet conditions. Water entering a power tool greatly increases the risk of electric shock.
Handle the power cord with care. Never use the cord to carry power tools or pull the plug from a socket. Keep cord away from high temperature, oily liquids, sharp edges or moving parts. Replace damaged cords immediately. Damaged cords increase the risk of electric shock.
When operating power tools outdoors, use extension cords specifically designed for outdoor use.
Personal safety
Stay alert, watch what you are doing at all times and use common sense when operating a power tool. Do not use a power tool while you are tired or under the influence of drugs or drugs that slow the reaction, as well as alcohol or drugs. This could result in serious injury.
Wear appropriate clothing. Loose clothing, jewelry, or long loose hair can get caught in moving parts while the power tool is running. Keep your hair, clothing, and gloves away from moving parts. Hands must be dry, clean and free from traces of oily substances.
Avoid sudden activation. Make sure the On/Off switch is in the "OFF" position before plugging in the power tool. Do not carry power tools with your finger placed on the on/off switch.
Remove adjusting and/or setting keys before switching on the power tool. A left key caught in the moving parts of the power tool may result in damage to the power tool or serious injury.
Keep your balance secure. Use good support and always keep your body firmly in balance. Proper footing and balance allow for reliable control of the power tool in unexpected situations.
Use equipment that ensures your safety. Always wear safety goggles. A respirator, non-slip safety boots, hard hat, or ear protection must be used for the appropriate conditions.
Safety Rules for Working with a Cordless Drill Driver
Do not drill into walls or other surfaces where electrical wiring runs. If this situation is unavoidable, turn off all fuses and/or circuit breakers that supply electrical power to the work area.
If the drill/nozzle gets stuck while working, turn off the drill immediately, release the drill and then continue working.
Wear noise canceling headphones when using a power tool for extended periods of time. Prolonged exposure to high intensity noise can cause hearing loss.
Always wear safety glasses when using this power tool. Use a respirator for work that generates dust.
Hold the workpiece securely when drilling. Never hold a part in your hand or with your feet. Poor fastening of the part can lead to deformation of the tips leading to loss of control over the tool and possible injury.
Never leave the on/off key locked in the "ON" position. Before turning on, make sure that the on / off key is in the “OFF” position. Accidental starts may cause injury.
Position yourself so that you are not caught between the tool or accessory handle and walls or poles while you work. If the accessory is bent, this will cause kickback from the power tool and may cause injury.
Only branded chargers may be used, chargers from other manufacturers may cause a fire.
It is allowed to use only branded battery, rechargeable batteries other manufacturers may cause a fire.
Do not overload the cordless drill driver, use the product strictly for its intended purpose.
Rules for the operation of equipment:
Using the Power Tool
Use clamps, clamps, a vise, or other method to securely hold the workpiece. Holding the part with your hand or body is not secure and could result in loss of control, tool breakage, or injury.
Do not overload the power tool. Use power tools appropriate for your job. The right power tool allows you to get the job done better and ensures greater safety.
Do not use the power tool if the "ON/OFF" key does not work. Any power tool with a defective on/off switch is HIGHLY dangerous and must be repaired prior to use.
Disconnect the plug from the power source before making any adjustments, changing accessories or accessories, or when storing the power tool. Such preventive measures safety features reduce the risk of accidentally starting the power tool.
Keep power tools out of the reach of children and other people who are not familiar with power tools. Power tools are dangerous in the hands of unskilled users.
Carry out the necessary maintenance of power tools in a timely manner. Properly maintained power tools with sharp blades make the job easier and more efficient and increase safety. Any change or modification is prohibited as this may result in damage to the power tool and/or personal injury.
Regularly check tool adjustments, and check for deformation of working parts, breakage of parts, and conditions of the power tool that may affect wrong work power tool. If there is damage, have the power tool repaired before starting work. Many accidents are caused by poorly maintained power tools. Establish a periodic service schedule for your power tool.
Use only accessories recommended by the manufacturer for your model. Accessories that may be suitable for one power tool may become hazardous when used on another power tool.
Rotation speed adjustment:
The cordless drill is equipped with an "On / Off" button, which has the ability to adjust the rotation speed. The rotation speed depends on the intensity of pressing this button, i.e. the harder you press, the higher the rotation speed and vice versa.
Right-left rotation switch:
Has three positions:
Left hand rotation.
Right hand rotation.
· Intermediate (in the middle) position, which provides blocking of inclusion.
Attention! It is strictly forbidden to switch the direction of rotation until the product comes to a complete stop!
The range of cordless drills includes two-speed products. Low speed rotation provides a low rotation speed and high strength moment to complete heavy work, as well as screwing screws.
Choice high speed is designed for light work at high speed and low torque.
Attention! Clearly set the position of the speed of rotation, avoid the intermediate position: this leads to damage to the gearbox.
Torque adjustment:
There is a “drill” icon on the ring for switching the position of the moment force. This position is intended for drilling and time-consuming tightening of screws.
Quick stop:
When you release your finger from the On/Off switch button, the product automatically and momentarily stops.
Charging the battery.
To charge the battery you need:
· Disconnect the battery from the drill by pressing the two side buttons (left and right) on the battery and, pulling it down, remove it from the body of the cordless drill/driver.
· Connect the charger to a 230V power supply, the red indicator will light up.
· Observing the polarity of plus with plus, minus with minus, install the battery in the charger.
· When charging is complete, the green indicator light will turn on.
Important:
· Battery charging time 1 hour
Use only branded chargers to charge the battery. !. Do not use a charger designed for one model to charge another model.
· The rechargeable battery is designed for 500 charge/discharge cycles.
· After a full charge, the battery lasts for 1 hour without load.
· During the first few charges, the battery capacity is filled to 80%. With subsequent charges, the capacity increases to a maximum.
· The capacity of the rechargeable battery decreases as the work progresses.
· If you have not used the product for more than 30 days, you must first completely discharge the battery and only then proceed to charge it.
· If you do not use the product for long period time, the battery capacity decreases, it will increase after several charges.
Rules for the care and storage of equipment.
In the process of storage, adjustment or replacement of nozzles, it is necessary to disconnect the battery from the product, the switch button "On / Off." should be in the off position. This reduces the chance of accidental activation.
During storage, keep the battery away from metal objects: paper clips, coins, keys, nails, screws - and other small metal objects that can cause contact internal parts battery, causing sparks and possible fire.
Check the product for jamming of rotating parts, breakage and other situations that adversely affect the operation of the cordless drill/driver.
During operation, hold only the insulated parts of the cordless drill/driver with your hands.
Be sure to hold the product with both hands!
In case of jamming, immediately turn off the product, change the direction of rotation, press the "On / Off" button. and slowly pull the product towards you.
It is strictly forbidden to touch the rotating cartridge or nozzles with your hands.
During the installation of the drill, make sure that the shank is correctly positioned on the jaws of the drill chuck.
Do not install broken or worn attachments.
It is forbidden to move a working cordless drill/driver along the body.
Attention! To avoid damage to the battery after purchase, you must fully charge the battery for 5 hours!
Rechargeable battery/charger.
· To avoid damage to the battery, we recommend that you use only chargers under the trademark https://pandia.ru/text/78/486/images/image009_1.png" alt="Adobe Systems" width="58 height=16" height="16">. Обслуживание, выполненное неквалифицированным персоналом, может стать причиной поломки инструмента и травм.!}
Life time.
Subject to the requirements specified in this manual and in the warranty card, the service life of the product is 3 years
Guarantee obligation.
Electric tools are covered by a warranty, according to the period specified in the warranty card.
You can familiarize yourself with the terms of warranty service in the warranty card attached to the instruction manual.
December 14, 2016 No comments
The screwdriver has become today one of the most popular tools among professionals and home craftsmen. It is useful when assembling furniture, installing drywall and plywood structures, laying roofs from metal tiles and other works. Let's talk about this tool in more detail.
A screwdriver is a hand-held electric tool for installing or removing fasteners and drilling. A screwdriver looks like a drill, and the principle of operation of these tools is also similar: an engine located in the body drives a nozzle through a gearbox, which does the work. The difference lies in the energy source (the screwdriver works on DC) and a lower frequency of rotation transmitted to the nozzle. The latter is due to the fact that the screwdriver was originally adapted to work with fasteners, at which high speeds are not needed. True, modern screwdrivers and in this parameter differ less and less from drills. It is not for nothing that most manufacturers position their tools as multifunctional, calling them drills-screwdrivers.
On the body of the tool there is a start button, a reverse button, a torque setting clutch and a speed switch.
Here, some screwdrivers have a backlight. The battery is inserted into the body from the bottom of the handle and securely fastened there with latches. This arrangement contributes to a good balance of the instrument.
SCREWDRIVER DEVICE:
- 1 - keyless chuck;
- 2 - torque setting clutch;
- 3 - speed switch;
- 4 - backlight;
- 5 - power button;
- 6 - reverse button;
- 7 - battery;
- 8 - battery discharge indicator.
The chuck is designed for fastening nozzles (bits and drills) and transferring rotational motion to them. The most common keyless chuck, which allows you to easily clamp the nozzle without the use of an additional tool.
Manufacturers also produce specialized power tools in the line of screwdrivers - for example, electric screwdrivers that are popular today, differing small size And low power. They are great for small repair work in the apartment, in the country. Impact wrenches, unlike them, have great power, they will help to unscrew, say, rusty bolt when removing the wheel from the car.
Torque setting clutch and speed switch.
Rotating torque clutch, desired value set opposite the risks on the body of the screwdriver.
Double sleeve keyless chuck. When installing and removing nozzles, the couplings rotate in different directions.
Additional cuff for setting the operating mode of a powerful screwdriver (twisting, drilling, drilling with impact).
An electric screwdriver is great for small repairs. impact wrench has increased power and can become an assistant during construction.
Main characteristics of the tool
When choosing a screwdriver, first of all, you need to pay attention to two parameters - torque and rotational speed. The torque value shows how much force is applied to the screw (drill) being screwed during operation. From this will depend, for example, a hole
What diameter can this screwdriver drill? In household tools, the torque is 10-16 N m.
For professional models, this figure can reach up to 130 N m. The rotation speed for household tools is in the range of 400-550 rpm. For screwdrivers with a drilling function, it reaches 1,300 rpm. Budget models usually have 1-2 speeds, a professional tool is most often three-speed. In addition, the rotational speed is adjustable within one speed by pressing the power button.
Batteries serve as a power source for screwdrivers. Most often, nickel-cadmium, lithium-ion and nickel-metal hydride batteries are used for these purposes. The output voltage of the batteries can be in the range of 3.5-36 V, but the most applicable range is 9.5-14.4 V. The power of the screwdriver depends on the voltage, although the dependence here is not direct.
The most important parameter of a battery for screwdrivers is its capacity, measured by the number of hours during which it is able to provide the declared current strength. In addition, batteries differ from each other in recharging resource, self-discharge rate, and the presence of a memory effect.
Nickel-cadmium (Ni-Cd) batteries
Recharging resource - within 1,000 times, high self-discharge, but they have the lowest price among other types of chargers.
Hybrid (Ni-MH) batteries
The resource reaches 1,500 recharging cycles, they have an increased capacity, they are discharged by 1% per month, the price is average.
Lithium-ion (Li-Ion) batteries
They have a reduced discharge time, there is practically no self-discharge, the resource reaches 3,000 recharge cycles, the price is the highest.
Screwdriver bits
When working with the tool, nozzles are used (bits for working with fasteners and drills). The shank of the nozzles is made in the form of a hexagon, which facilitates its installation. Bits can be clamped directly into the chuck or fitted into an adapter clamped into the chuck. The working part of the bit is like a screwdriver of such a configuration, which depends on which fastener this nozzle is used to work with.
Getting started, you need to choose a bit that matches the head of the fastener. The most commonly used are cross bits, which come in PH and PZ standards. PH is short for Phillips. PH bits are cross-shaped, universal, they can be used for a variety of fasteners. Sizes - from 0 to A, the most popular is No. 2. The PZ designation is derived from Pozidrive, these are also bits with a cross-shaped working part. In addition to the main large ribs, they have A additional smaller diagonal ribs. Thanks to them, the area of adhesion with fasteners is even larger than that of PH-bits. The sizes of such bits are from 0 to A, the most common ones are 2 and 3.
For repair household appliances and cars are indispensable without T-bits (from Torx Hole), with which you can unscrew and tighten the screws with a star hole on the cap. Flat, or slotted, bits are suitable for working with fasteners in soft material, at not too high a load. Such bits are marked SL (from Slot).
To work with bolts and nuts, use bits with a working part in the form wrench. They can only be used with fairly powerful screwdrivers (wrenches). Bit sizes - from 6 to 13 mm, but we must remember that this is the size of the bit itself, and not the bolt or nut.
Screwdriver bit sets often include drill bits with a hex shank. An angle attachment will help when working in hard-to-reach places. Drill chucks for drills with cylindrical shank are often used as nozzles for screwdrivers.
Additional screwdriver options
Screwdriver options different manufacturers may differ significantly. Their presence increases the convenience of working with the tool, but at the same time they can significantly increase the price of a screwdriver. Therefore, when choosing a tool, you should evaluate the need for a particular option.
- Illumination - one or more LEDs located radially in front of the housing. Makes it easier to work in poorly lit areas.
- Removable handle for comfortable holding of the tool while drilling. It will help when working with a powerful tool, using large diameter drills and drilling with impact.
- The depth gauge is useful for serial drilling of identical holes.
- The clothespin makes it easier to fix several nozzles on the body or the tool itself on the master’s clothes when moving along construction site(Convenient when working at height).
Models from different manufacturers
High performance compact and powerful cordless drill/driver. Suitable for working with fasteners and drilling. Torque can be controlled by presetting a 5-stage torque clutch and drilling position. Has one speed and keyless chuck. The package includes a charger, battery pack, plastic case.
The cordless drill/driver is designed for drilling holes in various materials, as well as screwing and unscrewing screws and screws during assembly work. Thanks to the ergonomic handle with rubber grip and low weight, the screwdriver will become indispensable assistant at home. The kit includes a rechargeable flashlight, two rechargeable batteries, a charger, a set of bits, a plastic case.
This drill belongs to a new generation of cordless power tools with new Li-lon batteries. The new motor design provides economical energy consumption, which significantly increases the operating time. The ergonomic handle and body are rubberized as much as possible, which contributes to the reliable holding of the tool. The model is equipped with a holster for carrying on a belt. The kit includes an extra battery, charger and flashlight.
If you are not working in construction company where a competent person is engaged in the selection of a tool, most likely you need household equipment for non-professionals. How to understand the classes of power tools and understand whether the power of the model you like is enough? And vice versa - how not to overpay for those characteristics that you do not need?..
We understand how power tools and hand-held electric machines are classified.
Power classification
It's not about how loud the puncher knocks and whether you can hear the electric saw at the other end of the village. Power is the very characteristic that determines the ability of the tool to work for a long time, without stopping and overheating. How important this is depends on the tasks that are set for the equipment and the conditions of its operation.
- Industrial and Heavy Duty are portable power tool classes not found on store shelves. These are not just professional units used by craftsmen from housing and communal services or masters "for an hour". They work without a break for 16 hours, have reduced safety indicators, as they are intended for the work of professionals.
- Heavy Duty have all the same characteristics and, in addition, increased dust and moisture protection and the ability to use equipment and accessories from other models. In other words, "heavy artillery" among electrical equipment.
- Professional as a class is found on specialized shelves shopping centers. They already have higher security requirements, as they are known to be used by less skilled operators. They can be allowed for use in harsh conditions, as well as expand their “specialization” - for this, interchangeable nozzles and other accessories often come in a set. The target audience of this class are foremen working on call or in a small production in one shift.
- Hobby - a class of equipment that usually sits in a box for weeks and is removed for small household needs: repairs or handicraft items. It is allowed to operate extremely carefully, it is not allowed to use it for more than half an hour: a 15-minute break should be taken. A big plus is a high safety rate for non-professionals.
Classification by purpose
The most familiar division of tools for us is according to the type of work that needs to be done.
- And, finally, auxiliary tools belong to a separate class of tools: guns (glue, soldering and for knitting reinforcement), construction vacuum cleaners and hair dryers, dust collectors, spray guns, mixers for mixtures and solutions.
Classification by method of operation
Electrical safety classification
This classification is according to the method of protection against damage. electric shock– and the following are the most serious. They are placed at the end of the article because to get to know them you need an understanding, for example, why professional tools security class below (this is described at the beginning of the article).
Classes of power tools and hand-held electric machines can be determined by marking.
| Class | Working insulation | grounding | purpose | Precautionary measures |
| 0 | Eat | No | Work in rooms without increased danger | The tool must be installed in an instrument with a grounded housing. |
| 01 | Eat | Grounding fixture without grounding conductor | ||
| 1 | Eat | Earthing device with conductor, earth-contact plug | Work in industrial premises and residential buildings | Connect to a grounded outlet. Working with rubber gloves |
| 2 | double or reinforced | No | Work in industrial premises | No (except for operation in wells and metal containers) |
| 3 | Eat | No | Any conditions, including in especially dangerous rooms | No |
The same classification of power tools for electrical safety is applicable to other household appliances: the first class of electrical safety is most common among technology; the third is universal.
Heat resistance classification
The lower this class, the more often you have to stop the device so that it cools down (20 minutes of operation after 15 minutes of a break is the optimal value for power tools, with an increase in the class, the operating time also increases).
The resistance to heat itself depends on the material of the winding.
| Class | Winding materials | Maximum t |
| Y | Cellulose or silk | 90⁰C |
| A | Cellulose or silk with dielectric treatment | 105⁰C |
| E | Resin and organic film | 120⁰C |
| B | Mica | 130⁰C |
| F | Synthetic materials or asbestos | 155⁰C |
| H | Elastomers and glass fibers impregnated with organosilicon | 180⁰C |
| C | Mica, ceramic, glass, quartz with inorganic treatment | 180⁰C |
Classification according to the degree of protection against the penetration of foreign objects
For convenience, the marking of the IP-XX format is used, where the first digit in place of X indicates the degree of protection against solid particles, the second - from the penetration of moisture into the device.
| 1st digit | Decryption | 2nd digit | Decryption |
| 0 | No protection | ||
| 1 | Protection against bodies with a diameter > 5 cm | 1 | Protection against moisture falling on the device from above |
| 2 | Protection against bodies with a diameter > 2.5 cm (operator's fingers) | 2 | Protection against moisture falling on the device at an angle of 15 ⁰ |
| 3 | Protection against bodies with a diameter of 2.5 mm (cables) | 3 | Protection against moisture falling on the device at an angle of 45 ⁰ |
| 4 | Protection against bodies with a diameter > 0.1 cm | 4 | Full moisture protection |
| 5 | Complete protection | 5 | Protection against moisture entering the instrument under pressure |
| 6 | Absolute protection (including against dust) | 6 | Protection against moisture penetration in case of short-term drowning |
The marking is designed to provide the user with an understanding of the hazard class of the power tool as much as possible. If doubts still remain, you need to consult with a specialist, be sure to indicate the qualifications of the operator for this tool, the conditions of use and the duration of work.
Please check the portable power tool requirements before purchasing. They are regulated state standards And specifications on electrical safety.
You can get acquainted with them, for example, on the Energokontakt website.
First of all, we list what applies to portable power tools. These are electric soldering irons, electric drills, screwdrivers, wrenches, furrow cutters, electric hammers, perforators, grinding machines, portable electric heaters for technological needs, step-down transformers for powering power tools, local lighting fixtures, portable switchboards and other current collectors.
Classes
Portable power tools are divided into classes.
The zero class includes a power tool with working insulation, without grounding elements, not belonging to the second and third classes.
The first class power tool has a working insulation and an element for grounding. Its wire leading to the power source must be equipped with a grounding conductor and a plug with a grounding contact.
Class 2 power tools have double or reinforced insulation, but no grounding elements.
The power tool of the third class is designed to operate at extra low voltage (not more than 42 volts) and does not have any electrical circuits operating at a different voltage.
Voltage for tools of the first and second classes - no more than 220 volts at direct current, 380 volts - at alternating current.
room
The voltage of the tool must not exceed 380/220 volts when working in rooms without increased danger and 36 volts in other rooms or outside them.
In rooms with increased danger there is one of the following factors: high dampness (relative humidity more than 75%); temperature above 35ºС; conductive floors; conductive dust; the possibility of simultaneous contact with the metal structures of the building that are connected to the ground, or with technological equipment - on the one hand, and with the metal case of electrical equipment - on the other.
Particularly dangerous are rooms with a relative humidity of about 100%; with a chemically active or organic medium; containing two or more risk factors.
Main general requirement for individual users - to work from the mains only if the power tool has a non-removable flexible cord with a plug. The cord must be protected from damage and contact with damp, hot and oily surfaces.
When the plug is turned on, its design must ensure the early closing of the grounding contact, and when turned off, the subsequent opening. It also needs to be protected from moisture. The power tool must be quickly connected to the network and disconnected from it (but not spontaneously).
Faults
And super important! If any, even a minor malfunction is detected, work must be stopped immediately!
Typical malfunctions of a portable power tool include: damage to the plug or cord; fuzzy operation of the switch; leakage of lubricant from the gearbox; sparking of the collector brushes with the appearance of a circular fire on the surface; the appearance of smoke, the smell of burnt insulation, hanging noise, knocking or vibration.
To provide safe work it is very important that the body of the power tool is zeroed.
Human
Power tools may only be operated by persons specially trained in safe handling. In the event of a malfunction, you cannot repair the tool or its cord and plug yourself - such repairs are usually not of high quality.
When working with power tools, depending on their type, you need to use personal protective equipment, which includes a cotton suit or gown, dielectric gloves, galoshes, rubber and rugs, etc. In especially dangerous rooms application individual funds protection is a must!
Before starting work, it is necessary to carefully inspect the power tool for proper grounding and insulation of wires, the absence of bare live parts and defects. Defective power tools must not be used!
At the end of work, do not forget to unplug the power tool from the mains.
During repairs and construction works You can't do without a good quality screwdriver. Such a tool is a necessary thing if you need to assemble furniture, unscrew old screw or hang a cornice or wooden shelf. Because on modern market a huge range of such devices is presented, it is rather difficult to stop the decision on one or another model. But how to choose a cordless screwdriver for the home? Which functional characteristics are of particular importance, and what can be easily overlooked? How not to make a mistake when choosing? More about this in our publication.
Cordless screwdriver for home use in equally and owners of apartments, and those who live in their own cottage. Basically, such a device is used for:
- Screwing and unscrewing fasteners (bolts, self-tapping screws, screws, screws);
- Installation work (to tighten anchors and dowels);
- To drill through wood and metal surfaces;
- To cut into metal parts carving.
This device consists of several elements:
- An electric motor that rotates at a certain speed;
- Reducer planetary type, which is equipped with a clamping chuck and transfers the force to the spindle;
- Attached to the gearbox by a clutch that regulates the torque;
- A clamping chuck for attaching nozzles (bits) to the motor shaft.
- An electronic control system equipped with a special button for starting the device and a reverse switch;
- A battery that is used as a power source.
Varieties of screwdrivers
The name "screwdriver" is often used to name several types of tools, the functionality of which is largely similar. We can distinguish the following main types of screwdrivers for the home:
- Electric wrenches;
- Electric screwdrivers;
- Drill drivers (the most common type of these devices)
Torque
This indicator determines the force with which the screwdriver resists the load or applies it to the screw being screwed. Typically for domestic purposes this device equipped with torque ranging from 10 to 15 Nm. Professional screwdrivers have a torque of up to 130 Nm. Such functionality is allowed to drill fairly hard materials. The motor shaft for professional screwdrivers makes 1300 revolutions per minute, for household data devices the figure is 500 revolutions. 
The range of standard sizes (diameter and length) of the screwed screws, as well as the hardness of the available working surfaces, depends on what the torque is. An important difference between a screwdriver and other power tools is that you can adjust the torque due to the presence of a special limiter (a ring located after the chuck). Thanks to this functionality, it is possible to reduce to an absolute minimum the likelihood of bit wear, too deep recession into the surface, as well as a breakdown of the slot at the self-tapping screw. The screwdriver is protected from overload by a ratchet at the motor coupling. It is she who allows the rotating shaft to slip freely. Thanks to the set maximum torque, you can not overload the engine and turn out the tightest screw. 
Good battery
When thinking about how to choose a screwdriver, be sure to carefully consider the battery. After all, it is not very comfortable to run around to recharge such a device every half an hour. In principle, it is not difficult to stop the decision on one or another option. It is enough to choose a more powerful analogue. IN ideal case You can also buy a spare battery. In some models, such a battery is included. The time required for recharging differs depending on the device. For example, for a professional screwdriver, this is about an hour, for an amateur - about seven hours. 
Types of batteries
As a rule, several types of batteries are used in screwdrivers:
- Lithium-ion;
- Nickel-cadmium;
- Nickel metal hydride.
The most popular at the moment are screwdrivers equipped with environmentally friendly Ni-MH batteries. In addition to environmental friendliness, they have several advantages: compact size, low weight, no memory effect. But there are also disadvantages: such batteries do not like electrical overloads and low temperatures. In addition, their cost is quite high. But they are more powerful and don't have as much memory effect as nickel-cadmium ones. The number of recharging with a stable capacity is 1500 times. Important: you can not store these batteries in a discharged form, only in a charged one. 
Another battery option is nickel-cadmium. They are more toxic. The number of recharges here is twice that of Ni-MH (nickel-metal hydride). This option is cheaper, it is not at all afraid of frost. But there are also disadvantages: batteries of this type suffer from strong self-discharge and memory effect. For storage, it is better to completely discharge them. Otherwise, there is a risk of getting a battery with a lower capacity.
Sometimes there are models with lithium-ion batteries. This type is sensitive to low temperatures. They don't have high power. The number of recharges is within 3000. There is no memory effect. The cost of such batteries is quite high, although this option is quite convenient to use. Service life and allowable number of charge cycles per this case, at least two or three times higher than the same performance of nickel-cadmium batteries. Solving the question of how to choose a good cordless screwdriver, take the time to choose a battery. After all, it is this component of the device that is almost half of its cost. Therefore, it is important to compare the following parameters:
- Battery capacity and voltage;
- Absence or presence of a memory effect;
- Absence or presence of self-discharge.
The battery is a removable element consisting of several power sources concentrated in a common housing. Such elements are fastened together with plates. At the output, the total voltage is summed up, amounting to 18, 24, 12, 10 volts. The capacity depends on the volume of the element installed inside the battery. It is she who determines the time of work and total number recharging. The capacity decreases over time. The charge memory effect is the ability to lose capacity when the battery is not discharged and then fully charged. That is, you need to completely discharge it before charging. An idle charged battery loses its charge anyway. In this case, not only the output voltage of the battery is important, but also the ratio of the current to the operating time. This value is measured in amperes per hour. Higher scores provide more extended period the time the battery will hold a charge.
Which drill chuck to choose?
There are several types of chucks for screwdrivers: key and keyless. For the key, a special gear-type key is used. Such a cartridge may have either one or two clutches. In the second case we are talking about the quick release mechanism. Keyless chucks can be two- or single-sleeve (it is much easier to work with this option, because the entire operation can be performed with the movement of one hand). We recommend taking screwdrivers with a quick-release chuck, they are much more convenient and easier to use. 
The presence of a reverse
Reverse or reverse stroke helps to pull out solid material a hopelessly stuck drill or unscrew a tight screw. The switch to the reverse mode for convenience is located directly with the start button of the device. It has two positions. Thanks to the position between them, the device can be blocked. 
Design and comfort of use
If it is important for you to purchase a good device, you should not trust viewing beautiful photos, because comfort is difficult to determine visually. It is better to hold such a device in your hand, check if the buttons are tight, and whether it is convenient to switch them.
Equipment
Depending on a particular model, the complete set of a screwdriver may differ. IN the best option– the presence of several nozzles for different heads of screws. So you can save both time and money on their subsequent purchase.
Key Findings
For a household screwdriver, several parameters are important:
- Torque indicator from ten newton meters;
- Revolutions per minute 400-500;
- Two operating modes (drilling and twisting);
- Reverse function;
- Battery type of device;
- Nickel-metal hydride or nickel-cadmium battery type:
- Voltage ranging from 10 to 14.4V;
- It is better to opt for a higher value of ampere / hour;
- The presence of a flashlight (as additional lighting during operation or as a device to ensure the complete discharge of nickel-cadmium batteries);
- Special belts for comfortable accommodation device on the master's belt.
