Screwdrivers: varieties, characteristics and features of choice

In the 80s of the last century, during the boom in housing construction, specialists in furniture assembly, installation of windows and doors, installation of wooden country houses were respected and respected people. It was impossible to do without them when building a house, a cottage, a summer residence. Despite this, the profession of a carpenter and a builder was considered not prestigious, difficult and low-paid.

Modern young civil engineers and foremen who make an individual project of furniture or interior design on a computer in a matter of minutes will no longer remember the distant times at the end of the 20th century, when professional builders and home craftsmen performed all work without drawings using a hand drill, drill with a rotary , screws, chisels, hammer, pliers, screwdriver and a set of keys. According to statistics, during the working day, each of them had to screw about three thousand screws into wood, concrete or brickwork using an ordinary screwdriver.

The screwdriver is the most demanded tool after the hammer drill among assembly fitters in large enterprises and among home craftsmen. The screwdriver allows a professional and a home craftsman to quickly and without significant physical effort perform a number of such works: repair the car, attach a curtain rod, change the interior trim in the car, repair a sofa or furniture set, hang the front door on hinges, assemble a cabinet from separate parts, install an armored door or a plastic window, drill a small diameter hole in a wooden board or wall, to hang a picture of your favorite painter or fix the bracket for installing a plasma panel.

The versatility of this versatile tool is far superior to a conventional impact wrench or hammer drill. With the help of an additionally connected gearbox and replaceable nozzles, the following operations can be performed with a screwdriver:

• the cutter will make it possible to easily cut wood, sheet metal, drywall and roofing material;
• the fan impeller will help to mix the mortar or polymer compound for pouring the floor;
• a washer and polishing paste will help you quickly polish any surface to a mirror shine;
• an eccentric cam turns a screwdriver into a small-power perforator or jackhammer;
• Victory drills make it possible to make holes of an ideal shape without cracks in material of any hardness - wood, glass, metal, concrete, asphalt, granite.

There are many modifications of screwdrivers produced by different manufacturers. They differ from each other in the power of the electric motor, the speed of rotation of the spindle and the magnitude of the torque. To screw a screw into a tree, a chuck rotation frequency of 400-500 rpm is sufficient. Professional craftsmen and builders usually use higher power devices with a speed of 1100 rpm or more.This makes it easy to drill holes for dowels in concrete, to assemble and install wooden, plastic windows, aluminum structures, suspended ceilings and interior details.

The screwdriver resembles an electric drill in appearance.

By function, this versatile tool can replace:

• wrench;
• screwdriver;
• puncher;
• a spatula for mixing paint;
• milling machine;
• polishing washer;
• circular saw;
• demolition hammer of low power.

The screwdriver circuit is practically no different from an electric drill.

It consists of the following nodes:

• case (metal or plastic);
• single-phase DC collector motor;
• planetary reducer;
• collet chuck;
• rechargeable battery.

There are different modes of operation of this power tool.

• Forced braking of the spindle - allows you to correctly distribute the force when screwing in screws. Protects the wood from splitting and allows, if necessary, to easily unscrew a screwed-in with effort, painted over and outdated screw.
• Spindle lock - used to replace the nozzle in the chuck. Allows you to free both hands to perform the replacement operation.
• Reverse - occurs due to a change in the polarity of the supply voltage on the electric motor. It turns on by pressing a small button located on the handle next to the trigger. To prevent damage to the tool in case of accidental turning on the reverse at high engine speeds of the screwdriver, this button has a safety lock with mechanical fixation. Reverse mode allows you to tighten and unscrew screws without connecting an additional gearbox.

• Pulse mode - arises when the tangential component of the torque appears, directed perpendicular to the axis of rotation due to a sharp change in the spindle speed. Pulse mode prevents the screw from jamming when screwing into dense wood (oak, beech) or splitting the wood due to over-tightening.
• Impact mode - arises due to the interaction of the eccentric and the ratchet located in the gearbox housing. This operating mode makes it easy to drill holes in sand-lime brick and concrete, and also to use the screwdriver as a small jackhammer.
• For the convenience of working in narrow crevices and niches at the end of the screwdriver body, next to the cartridge, there is a bright light bulb, which is turned on by pressing a separate button.

Let's get acquainted in more detail with the principle of operation of the screwdriver in shock mode. To give the screwdriver a reciprocating movement along the axis of rotation, an eccentric is connected to the gearbox. When the engine rotates, it jams the flywheel on the gearbox shaft with a frequency of up to 2000 times per minute. The increasing torque from the running engine overcomes the ratchet spring force, the flywheel starts abruptly from a standstill and picks up speed. The tangential acceleration of the flywheel at the start of rotation is directed along the axis of the screwdriver. The resulting impulse pushes the tool body forward and backward along the flywheel rotation axis with great effort.

The similarity of a screwdriver when working in an impact mode with a jackhammer is actually only external:

• in a jackhammer, the source of impulses is the reciprocating movement of the piston inside the cylinder under the pressure of compressed air, the supply of which is controlled by spools;
• in a screwdriver, the source of impulses is the tangential component of the centrifugal force, which occurs during accelerated rotation of the eccentrics on the gearbox shaft after they are freed from jamming by spring-loaded cams under the influence of increasing torque from the engine;
• the impulse at the jackhammer is directed along the tool axis;
• the impulse of the screwdriver due to the tangential component of the centrifugal force is directed perpendicular to the axis of rotation.

The pulses follow each other at a frequency of about 2000 beats per minute, which ensures high impact mode efficiency and reduces recoil on the hand holding the screwdriver body. With the help of the impulse mode, it is easy to rip out of place a rusted, hammered, naughty screw filled with old paint or varnish, and it also makes it much easier to screw the screw into dense wood (oak, beech).

There are a large number of types and models of drills and screwdrivers from different manufacturers on the construction tool market. Depending on the power source used, screwdrivers, regardless of the manufacturer, are:

• electrical;
• pneumatic;
• hydraulic.

For work in difficult conditions (in a deep niche, narrow slots, when installing a suspended ceiling, when installing screws near power cables, servicing and repairing cars at a service station), it is convenient to use an angle screwdriver. Its handle is rotated 90 ° in relation to the chuck axis - this makes it easy to screw screws in corners and in confined spaces.

The pneumatic wrench is used as the main assembly tool at the workshop. To power the screwdriver and spray of enamel and paint, a stationary air compressor is installed in the service room of the service station.

Advantages: can be used when the air contains propane, butane, other explosive mixtures and fine silicate dust.

Disadvantages:

• increased noise during operation from compressed air escaping through the valve;
• the difficulty of using in rooms containing wood chips, abrasive or quartz dust in the air;
• the need to use personal protective equipment for eyes and respiratory organs during work.

The hydraulic impact wrench is used only as a stationary equipment due to the complexity of transportation and installation in a new location. The engine oil is compressed by a high pressure pump and fed through reinforced hoses to the screwdriver. Instead of an electric motor, a hydraulic turbine is installed inside the housing.

Advantage: the ability to create a large torque on the screwdriver spindle.

Disadvantages:

• the complexity of the design;
• high cost of repair and maintenance of the high pressure pump.

A type of screwdriver is a screwdriver. Serves for tightening and loosening bolts and nuts. To prevent thread stripping or breaking of hardened bolts from excessive force, it has a built-in friction clutch. When a bolt or nut is jammed, the clutch is triggered, preventing breakage or damage to an expensive tool.

Models of powerful professional cordless screwdrivers with a battery voltage of 24 V are on sale. They differ from the others in their increased power and increased operation time between charges. The high engine power allows you to effortlessly carry out car repairs at the service station. These powerful screwdrivers are used for assembling wooden cottages, drilling concrete walls and metal blanks. Its high dead weight makes it easier to punch holes in masonry and concrete, and to screw in and out rusted and painted screws.

Disadvantages:

• heavy weight;
• high price;
• the universal power supply unit is not suitable for charging the battery;
• it is impossible to charge through the adapter from the vehicle's on-board network.

A tool of industrial manufacture - a drill-screwdriver - has become widespread among builders and home craftsmen.The universal drill chuck is designed to accommodate drills with different shanks: square, tapered, hex, round, triangular and SDS. Among installers and builders, screwdrivers with a rechargeable battery with a voltage of 18 Volts enjoy well-deserved respect. The increased supply voltage provides higher power and autonomy for 10-12 hours from a single charge, this is quite enough for one work shift.

Advantages:

• long operating time from a single charge;
• lightweight rechargeable battery.

Cordless screwdrivers with 18 volt battery have a high capacity lithium-ion battery. Power tools with this battery can operate continuously for up to 24 hours. The Li-Ion battery can be recharged at any time without waiting for a complete discharge. Such a battery does not lose capacity due to violation of the charge-discharge mode; electrolyte crystals and sulfation of the plates do not fall out in it. Such a battery is lightweight and lightweight, it is resistant to low temperatures.

A screwdriver with a Li-Ion battery does not need to be stored in a heated room at the end of the work. It can be used without restrictions in winter in Siberia, Yakutia and the Far North. Cordless screwdrivers with a 24 volt battery can work without recharging for one week. Four charged lithium batteries provide continuous operation for a month.

I would especially like to note the "heavy artillery" in the large family of this type of power tool - cordless tape and brushless screwdrivers. The belt screwdriver looks like a machine gun. A plastic tape with self-tapping screws fixed in it is inserted into a special hole in the body. A special mechanism in the process of work feeds the next self-tapping screw into the chuck, the person only has to bring the tool to the right place and pull the trigger to start the engine.

The screwdriver belongs to the zero class of protection against electric shock. If water enters through the cooling slots and when the collector brushes are heavily worn, in rare cases, a supply voltage may appear on the case. The cordless screwdriver does not need to be connected to the electrical network, it is very convenient for them to work in the following cases:

• at high-rise installation work, where it is not possible to connect to the electrical network;
• in houses under construction, when voltage is not yet applied to the sockets;
• car enthusiasts, hunters and tourists who need to mount a tent or awning for rest and overnight stay using a screwdriver in hiking conditions, in the forest, at a halt, far from civilization and an electrical outlet;
• during the construction of cottage and summer cottages at a considerable distance from the city limits or the Moscow Ring Road;
• when performing installation and assembly work in hard-to-reach places - in swampy or rugged terrain and in places where there is no stable power supply.

The holster allows you to conveniently transfer the screwdriver from one place of work to another without a bulky plastic case and keep it constantly ready for action when both hands are busy - when installing on scaffolding, hanging cradle, in cable duct wells. A factory-made holster for a screwdriver has a number of disadvantages:

• made of soft material - thin imitation leather, nylon;
• gets dirty quickly during use;
• holster pockets can hold a small amount of replacement tools;
• the holster is placed on the belt, which is very inconvenient when performing assembly and installation work at a height - there is no way to simultaneously put on a safety belt with a carbine and a screwdriver in a holster.

If you need to perform a variety of work using a screwdriver at a distance from home or office using bits, socket wrenches and other tools, it is best to take a plastic case with you. If the work is scheduled for the evening or at night, you can put drills, a tap, a hammer, a tape measure, a marker, as well as a battery lamp, a flashlight, soap, personal hygiene products, brilliant green, ammonia, a tourniquet, adhesive plaster and more in the case along with a screwdriver ...

Each master can easily make a holster for a screwdriver from plastic packaging for antifreeze or automotive oil. To do this, you need to cut off the bottom of the canister with a jigsaw or a can opener. The canister with a screwdriver is fixed to the belt using a plastic clamp.

If the screwdriver is to be used as a drill for drilling a large number of holes in metal, brick, concrete for a short period of time, it is best to use drills with a hexagonal (hexagonal shank). This shape of the tail correctly distributes the force along the cutting edges of the drill, greatly speeds up and facilitates the work.

Consider a few more adaptations. A set of heads for screwing screws of different sizes, as well as bolts and nuts, allows you not to carry bulky and rather heavy sets of socket and box wrenches, screwdrivers and drills. Almost all the tools necessary for work, including a screwdriver, are placed in a convenient small plastic case.

Included with some models is a special carriage, which, after bolting on the desktop and installing a circular saw in the screwdriver chuck, instead of a socket wrench, turns the screwdriver into a circular saw - the workplace of a parquet flooring or cabinetmaker.

Car enthusiasts, locksmiths and men who do everything with their own hands purchase an electric screwdriver for household work in a plastic case with a full set of tools or a universal screwdriver-drill.

Purchased for reasons of maximum economy, a cheap tool very quickly reveals its shortcomings:

• fast battery discharge during operation;
• the impossibility of changing the speed of rotation of the cartridge;
• incorrect choice of the type of storage battery;
• purchase of an unreasonably high power screwdriver;
• wrong choice of cartridge;
• the screwdriver was imported into the Russian Federation illegally;
• buying a well-disguised used power tool;
• the battery has lost capacity from long-term storage without periodic recharging, or was repaired in artisanal conditions.

Obeying the standards of behavior, after powerful psychological treatment by the sales manager who works in the sales area, people most often act impulsively, being strongly impressed by what they have heard, choosing a screwdriver based on a well-memorized speech of the seller, on PR promotions promoted on the TV screen. the appearance of the tool, a beautiful box, discounts and "free gifts" for the promotion.

First of all, you need to pay attention to the appearance of the warranty card and packaging.If there are obvious signs of a fake, it is not recommended to buy a screwdriver at this outlet. There are a number of characteristic signs by which you can fairly easily identify a fake:

• vague or double contours of the logo, numbers and letters;
• eraser stains or traces of etched text;
• damaged hologram or air bubbles under the film, traces from a blade or needle;
• paint on the coupon burnt out in the sun or spreading from wet hands;
• presence of inscriptions unusual for the brand;
• use of old names or outdated symbols (Gold Star instead of LG);

• lack of a manufacturer's warranty certificate or its sloppy appearance;
• indication of the incomplete address and phone number of the manufacturer or their complete absence;
• sloppy type of packaging, traces of exposure to moisture, oils, solvents;
• incomplete completeness of the product;
• unusually low price and persistent attempts to “sell two for one”;
• obvious confusion or nervousness of the seller in questions about the origin of the goods and the place of warranty service.

Careless display of goods, a pronounced smell of insecticides, lack of air conditioning, the location of the store's sales area in a dark semi-basement room, obvious confusion, confusion or ridiculous excuses from sellers when asking to show a specific product, no sign with the name of the store and advertising at the entrance, banners with images of other people's goods and services, the absence in a conspicuous place of a copy of the IP registration are very serious counterarguments against buying a screwdriver in this store. After choosing a specific model of a screwdriver, you need to check the completeness, the presence of a stamp with the date of sale in the warranty card, the presence of a cash register receipt and require checking the performance of the power tool in all modes.

The purchase of cheap contraband goods from random sellers through an advertisement on the Internet or in one-day firms is very risky from the point of view of consumer protection: the possibility of a refund or exchange of a screwdriver in case of obvious deception or detection of a hidden defect during operation. The guarantee for contraband goods is valid, as a rule, until the store's doorstep or exit from the market, and in the future rests solely on the decency and conscience of the seller.

Before buying a screwdriver for home use, you need to carefully read the description of the selected model and the video materials that the manufacturer offers for review. When familiarizing yourself with these materials on the websites of sellers of power tools, it should be borne in mind that the description and videos in these places will have a pronounced "PR-connotation" - the shortcomings of a particular model can be greatly underestimated or they will be silent about them.

To get an objective picture, it is best to use first-hand information - on the manufacturer's website. If you have gaps in your knowledge of the English language, you can use machine translation, which is available on many Internet portals. Technical texts on the websites of screwdriver manufacturers, as a rule, do not contain adverbial expressions and complex grammatical constructions, so the "machine linguist" translates them quite accurately for understanding, with the exception of proper names (company names and surnames).

To identify the advantages and disadvantages of domestic, German and Chinese-made screwdrivers presented on the Russian market, an expert group was created with the involvement of designers, developers and technologists of the manufacturer of the power tool. Bench and extreme tests of screwdrivers of popular models from cheap, popular and professional segments were carried out when working in a pressure chamber with unfavorable conditions:

• high humidity - an ultrasonic water spray created during tests in a pressure chamber a relative humidity of 90%;
• low and high air temperatures - models were tested in the temperature range from -35 ° C to + 4 ° C;
• all models worked in continuous mode at 75% load for 12 hours;
• a stress test was carried out with imitation of jamming of the screwdriver chuck for 6 seconds with a fully charged battery without turning off the power to the electric motor;
• 1.5 thousand reverse switches were performed, followed by starting the engine of the power tool until the operating speed was reached for 10 seconds.

Further, a survey was conducted of users who work with a screwdriver daily for at least 7 hours during a shift. More than 2.5 thousand people of different ages and different specialties took part in the survey:

• joiners and furniture assemblers;
• car repair specialists at service stations;
• parquet flooring;
• handymen;
• high-rise installers.

In this article, we will consider screwdrivers that have an international ISO quality certificate and scored more than 80 points out of a hundred possible according to the stress test results. These are models of screwdrivers well known to specialists and installers.

• "Varyag DA-12 / 2LP" - manufacturer Russia, keyless chuck, battery powered, two-speed, chuck - Ø10 mm, reverse - yes, spindle fixation - yes.
• Interskol DA-10 / 14.4M3 - manufacturer Russia, keyless chuck, battery powered, 20-speed reducer, torque limiter, reverse switch, large plastic case for storing and carrying the screwdriver and replacement tools.

• Makita 6261DWPE - China manufacturer under license from Japan, T-handle, speed switch, shaft lock, high-power electric motor.
• Makita DF330DWE - made in China under license from Japan, removable battery 1.3 Ah, 10.8 V, weight 0.880 kg, keyless chuck with a diameter of 10 mm, additional battery, case.

• Bosch GSR 1440 - made in Germany, weight 1.3 kg, 25 steps, 1400 rpm, keyless chuck.
• Hitachi DS14DCL - made in China, reverse, electronic speed control, weight 1.4 kg, 2 batteries included, mains charger.

• Elitech SHA 10.8LK2 - China manufacturer, two speeds, built-in battery hidden in the handle, mains charger.
• "Varyag DA-14/2" - made in Russia, two-speed screwdriver, keyless chuck, battery, mains charger.
• DeWALT DCD771C2 - China manufacturer, shockless, 18 V, weight 1.6 kg, keyless chuck, spare battery included.

Users and experts point out the following advantages of these models:

• fast charging from the mains charger;
• low weight of the spare battery;
• a set of adapters for connecting to any type of sockets;
• the case with rubberized inserts is easy to hold in your hands;
• long operating time without recharging;
• ergonomic handle - the screwdriver is comfortable to hold in the hand;
• the set of interchangeable tools fits comfortably into the case;
• secure installation of the tool in the chuck.

The main disadvantage of all the respondents named a rather high price. All users of cordless screwdrivers note their mobility, functionality, ease of use, low weight, autonomy. When choosing a model of a screwdriver for home use, a non-professional mostly focuses on the manufacturer's brand, price and reviews on the Internet.

A selection of recent screwdriver purchases have been made by independent marketers.

According to the results of the sample, the manufacturers divided the places among themselves as follows:

• Bosch;
• Makita;
• DeWALT;
• Sparky;
• Black & Decker;
• Fieldmann;
• Hyundai;
• Interskol.

A brief overview of the screwdriver models that are the winners of the rating, scoring one hundred points out of a hundred possible.

Production - Germany. The steel hardened gears of the reducer are vacuum-coated with boron nitride 2 microns thick. This coating prevents the appearance of microcracks from metal fatigue and increases the edge hardness by 4.5 times. The rotation speed of the chuck in both directions reaches 1400 rpm at maximum speed. The battery is fully charged in 30 minutes, and the battery is charged to 75% in 15 minutes. The brightness of the built-in LED is 100 lumens (100 candles).

Manufactured in China under license from Japan. The two-speed planetary gearbox and 16-speed clutch provide a maximum torque of 44 Nm at a chuck speed of 1400 rpm. The hardened steel gearbox has a MTBF of approximately 10,000 hours. Reinforced 3000mAh Li-ion battery fully charges in 22 minutes.

Expert opinion is based on comparison of stress test results with manufacturer's stated specifications. In addition, when passing the test, experts gave an assessment to each screwdriver according to the following parameters:

• how comfortable it is to hold the tool with wet hands;
• the appearance of the case for laying the screwdriver and replacement tools;
• fastening a screwdriver and a removable tool in a case when carrying;
• battery life;
• the effectiveness of the lighting built into the handle;

• recoil from the tool when working on the hand;
• is it possible to change the tool in the chuck while working with one hand;
• how many screws can be screwed into a board of standard thickness in one hour of work;
• length of the power cord, convenience when storing it in a case;
• the possibility of using, instead of a circular saw, for sawing boards;
• the ability to connect a plow to prepare the floor for varnishing or for laying laminate over parquet;
• no need to contact the warranty workshop during the warranty period;
• availability in the workshop of the necessary units and parts for the repair.

The country of manufacture (Made in), indicated on the box of the screwdriver, does not really matter, since almost all manufacturers, for economic reasons, move their production to China. The entire process of assembling a screwdriver, including quality control at factories for assembling and assembling equipment in China, takes place on fully automated lines, without human intervention from components and consumables supplied from Japan, Germany and other countries.

This guarantees the high quality of the assembled tool - the computer manipulator that collects the screwdrivers is not subject to fatigue and stress, it is not worried about debts and other household problems. The insulation of all live parts of the screwdriver is checked in an automated quality control (QC) section by a breakdown test under a voltage of 3000 V after holding for two hours in a pressure chamber at a temperature of + 42 ° C and a relative humidity of 80%.

Screws can be tightened using a special drill bit or an inexpensive ratchet and ratchet screwdriver. Using this old-fashioned way of mounting dramatically reduces productivity and can lead to injury.

For the advanced DIYer and professional user, you need to purchase a replacement battery of standard capacity or reinforced. This will allow not to stop working due to a discharged battery and will significantly extend the life of the batteries: one battery is in operation until it is completely depleted, the second charged battery is in your pocket or on a charging glass. A mode of use, such as full charge - full discharge, has a beneficial effect on the condition and life of the batteries.

Lithium-polymer and lithium-ion batteries have no memory effect. On the plates inside the battery, crystals do not fall out of the electrolyte, which pierce the separator between the plates, which leads to a short circuit between the battery plates. In fairness, we note a significant drawback in the design of the lithium-polymer battery. Thin pole electrodes are quickly depleted during operation, after which the battery must be replaced immediately.

The best option is to purchase a two-speed screwdriver. At a reduced speed, it can be used to tighten screws, at a higher speed, it can be used to drill or cut metal and wood by installing a carriage and a circular saw.

After releasing the engine control button, the screwdriver chuck stops immediately and does not turn by hand. This is very convenient when changing attachments and allows you to stop at the right time.

Allows you to automatically stop the screwdriver motor when the specified force is reached. This will help prevent the screw from sinking too deep into the wood and prevent the head from breaking after screwing.

Modern models of the screwdriver are designed to be dropped from a human height onto a cement floor or concrete. During work, do not allow water, sand, debris and small objects to enter the ventilation openings. In summer, when the air temperature is above + 24 ° C, every 2 hours you need to take a break for 15 minutes. This will prevent the tool from seizing or breaking the insulation of the motor windings from overheating.

Despite the special waterproof design of the case and safe supply voltage, except for screwdrivers that plug into a 220 V outlet, in rare cases, a slight electric shock is possible, which, if safety rules are violated, can lead to serious injury to hands or fall from a height. Strict observance of PTB, PUE and periodical examination completely exclude such cases.

Based on the statistics of occupational injuries available in open sources, we will also pay attention to a number of points.

• Before performing installation work, using a screwdriver, it is necessary to clean the air in the production room from fine wood and silicate dust, vapors of flammable and explosive substances.
• To perform installation and construction work with a screwdriver in rooms of the first category for explosion and fire hazard, in accordance with the requirements of Federal Law No. 123-FZ of 22.07.2008, only a pneumatic screwdriver can be used. A compressor located outside the fire hazardous area supplies compressed air, which drives the tool, through hoses.In this case, the electric voltage is not supplied to the screwdriver, the appearance of an electric spark or arc, which can lead to an explosion or fire, is completely excluded.

For information on how to choose a screwdriver for your home, see the next video.