Many of their readers still remember those times when using fasteners or screwed connections to work with , one had to use only screwdrivers and conventional wrenches. It's understandable, it's not even necessary to talk about the high productivity of such works. Very often, to make the "drive" the screw into place, it was impossible to do without the drilling holes, because the efforts of the hand in this case are not enough for the to overcome the resistance of solid wood, not to mention the situation when it was required"Pierce" even the thinnest metal sheet. Several hours of such work - and the inevitable calluses on their hands, and the work progressed barely.
The situation has radically changed with the advent of screwdrivers .Initially, they were referred to in a kind of instrumental "exotic", causing genuine envy. But very soon these useful tools appeared in free sale, "migrated" to the public, and now are included in the mandatory "arsen
Contents of the article
screwdriver under the general name « screwdriver » Consumers often involve several types of this instrument, which still have differences with the overall similarity of functions. So, we can distinguish three main varieties:
The most popular demand is for tools that run autonomously, from batteries. However, it is quite possible to purchase the screwdriver , operating from the usual 220 network in the / 50 Hz. Tools with a cord for connection to an outlet are usually called "network".
It is necessary to get acquainted with the basic types of information - it will be easier to make a choice, realizing the expected nature of the work, its intensity and load on the instrument.
Despite the fact that the for its basic performance and general functionality, the screwdrivers are somewhat inferior to the standard drill drivers , they have their own specific advantages, which make these tools widely popular among professional masters as welland among amateurs. To these invaluable advantages of the , can include a small mass, a compact layout of the device, high ergonomics. This allows the use of battery screwdrivers in conditions, when use of a larger tool or is associated with large inconveniences, or even simply impossible.
. Similar to the tool is an indispensable tool for the assembly of small household appliances, computer and office equipment, and is widely used by craftsmen in the production or final assembly of furniture. Due to compactness, ergonomics and low weight, such screwdrivers do not cause fast fatigue of hands, and therefore are very convenient for work at height, including, for example, when mounting false ceilings.
Rechargeable screwdrivers are different in their layout. Many models have a cylindrical body, which, however, is equipped with articulated joint, which, if necessary, folds, to concentrate the clamping force of the hand.
Other screwdrivers have the usual "pistol" shape, but always very compact, comfortably lying in the palm of your hand.
In addition, very easy-to-use models are produced, in which a swivel connection is provided for the working head with a rotating chuck. This opens the possibility of tightening fasteners or dismantling most uncomfortable places where it is not possible to get a regular tool.
The compactness of these power tools is achieved through the use of small batteries, with a voltage usually within the from 3 to 9 V. Screwdrivers are not exposed to high speeds - usually from 150 to 250 rpm. For their direct purpose, this is quite enough, as well as the tightening torque of about 10 N × m. For the vast majority of fastening elements, especially in domestic conditions, such indicators are abundant enough. However, there are more advanced models, equipped with two-speed switch, and allowing to perform drilling operations with plastic and wood - the frequency of rotation can reach up to 600 rpm.
Almost all rechargeable screwdrivers are equipped with an adapter cartridge for bits with hexagonal shank ¼ ".Usually, bits for different types of fasteners, as well as small diameter drill bits with the same hexagon shank are included with the screwdriver.
Unlike the larger tool, the electric screwdrivers are often equipped with with a non-removable battery, placed in the product case. For charging, use a special unit power adapter , plugging into the outlet.
What in the end? If the owner has a good drill in his tool kit, and he only needs to mechanize the process with fasteners, the rechargeable screwdriver can become a very useful helper. In the convenience of this operation it surpasses the screwdriver, but it is considerably inferior to its functionality.
Another is an tool type that is very similar to the with the screwdriver, and even in certain circumstances it can be used in its quality, but still has features directly related to its direct purpose.
If the master has to use very often to mount or remove medium or large diameter threaded connections, then it is necessary to reduce drastically the operations using spannersthe productivity of their labor. A classic example is an assembled production assembly or, that is closer to private practice, auto repair or tire fitting workshops. In addition, in particular, when repairing machines, very often you have to deal with old, "sour" knots, which you can unscrew manually, even after processing with a special compound, is very difficult.
Output - application of percussion wrench .Its design is such that in addition to the usual rotational movement on the working part of the spindle, a special mechanism also transmits impulse actions with a certain frequency. In a word, these are the original " microdashes ", capable of stitching and unscrewing even very rusty nuts or bolts, without violating the integrity of the facets of their heads.
Most wrench have the usual "pistol" scheme, but can additionally be equipped with an detachable lateral handle for concentration of the clamping force when the connection is strained. Nevertheless, , there are also "direct" devices, with perpendicularly working head - for operations in hard-to-reach places.
Undoubtedly, this requires a special power of the drive - it usually lies in the range from 350 W for the smallest instruments and even up to 1300 W for professional-grade devices. The rotation speed here does not play a decisive role, and it usuallyis not large. But score achieves high torque, which even for the "weak" shock impact wrench is about 200 ÷ 300 N × m( compare, for example, with already considered battery screwdriver!), And in professional models, with an electric drive capacity of more than 1000 W, this figure can reach even 1000 H × m.
very similar is similar to with screwdrivers, but they are distinguished by the absence of a ring of maximum torque adjustment( "ratchet").The working tip of the spindle also differs - most often there is an adapter-square under the end heads. The sizes of the square for different models may differ - ½( most often for household-class models), ¾ or even 1-inch( for a professional powerful tool), and means , and the head sets should be purchased accordingly. Although, for this case there are special adapters.
end heads. Some manufacturers immediately provide for an increased flexibility of the adapter. So, in the center of the spindle-square there can be a socket for insertion of standard hexagonal ¼ "- shank bits or drill bits .
But even this does not add the wrench universality. Its specific electromechanical characteristics are still "sharpened" for specific operations. The high torque, yes still and with impulse mode, can be absolutely superfluous and even harmful when working with materials that do not require excessive force. A low rotation speed may not be sufficient to perform drilling operations.
In a word, percussion wrench , if the specifics of the work of the mater assumes its frequent use, it will be a good addition to the screwdriver, but it is unlikely to completely replace it in the householder's arsenal.
By the way, many well-known manufacturers produce tool sets, in which includes both drill-driver , and percussion wrench , which work from one set of accumulators. Here it is really a universal set of .True, the cost of it is quite high, and such a purchase must be really justified.
This is the most common and most commonly purchased variety of similar tools, which has increased versatility.
The overwhelming majority of similar screwdrivers is made according to the basic "pistol" scheme.
1 - case made of impact-resistant plastic( some models of professional class have an all-metal case).Inside there is an electric drive with control elements, a well thought-out air cooling system.
2 - pistol grip. In high-quality models has a rubberized lining, which prevents the slip of the tool in the hand of the worker, make the tool as convenient as possible.
3 - rechargeable battery with a locking mechanism in the handle. In most models it looks similar to the one shown in the figure. However, some modern screwdrivers are equipped with powerful batteries of compact type , which completely hide inside the handle, making working with tool more more comfortable.
4 - the button( trigger) trigger. Moving the trigger simultaneously smoothly adjusts the spindle speed of the screwdriver. Typically, the trigger is also covered with an overlay of rubber or soft plastic.
5 - the switch of a direction of rotation of a spindle( reverse).It is designed so that the switching process is as simple as possible - enough finger force.
6 - gearbox switch, which allows to change the operating modes of the tool - low speed with a large tightening force, or, conversely, the high-speed rotation necessary to perform drilling operations. This function is not implemented in all models.
7 - tool holder clamp - bit holder or drill bits .The design of the cartridge can be different. Some models are not equipped with a chuck - they have an hexagon socket ¼ inch for standard bit shanks or special drills .On the types of cartridges will be described below.
8 - clamping jaws of the cartridge.
9 - an indispensable element of any screwdriver - the mechanism of limiting the torque transmitted to the chuck. Usually, the - ratchet principle is used to ensure that when the specified torque is exceeded, the clutch slips with a characteristic sound. The number of positions of the torque setting can be different - from 5 ÷ 6 in inexpensive models to two dozen or more in professional tools. A drill mode is mandatory - when the rotation is transferred from the gearbox to the chuck without any torque limitations. This mode is indicated by the corresponding icon.
10 - the modern models screwdrivers in in are more often equipped with LED work area illumination system. The location of the LED may be different.
Thus, a similar type screwdriver is the most versatile, which predetermines its widest popularity among professionals and home masters.
When deciding on the purchase of a particular drill / screwdriver model, the future tool owner must clearly represent, for which purposes it needs, what operations it plans to perform and with which should be exploited. It is these preliminary " notes " that will become the base points when evaluating the characteristics of the proposed in the sale of devices.
Start consideration is advisable exactly with "energy" screwdriver .No matter how wonderful the tool itself is, its performance depends directly on the batteries, the cost of which, incidentally, is always more than half the price of the complete set. For sure , many had to deal with the situation when the screwdriver itself is still fully functional, but the output from with the creates a lot of problems. It is not always possible to find a suitable replacement - many manufacturers do not put batteries separately, trying, apparently, thereby stimulating users to purchase a new kit.
The main characteristics of the batteries for screwdrivers are voltage and capacity.
By the way, one can find almost identical screwdrivers from one manufacturer, differing only in the supply voltage and, as the investigation, power indicators. But even in this case it should be understood that the batteries are not interchangeable - the drive is designed for a specific voltage, and exceeding it will cause the to fail.
are indicated. In fact, the capacity of the battery is a value indicating how long the instrument can last on one fully charged battery without recharging. Naturally, the larger this value, the less it will be for the to interrupt the work to replace the power and position the cells for recharging.
Usually for household screwdrivers , used by from time to time , it is enough indicator of capacity in 1,2 ÷ 2 Ah. For intensive use of this indicator will be not enough - you should look for kits with with battery capacity of 2 ÷ 3 Ah.
The performance of the batteries is directly dependent on their types. This issue requires closer examination.
Thanks to the low price, similar AKB remain leaders on mass use in power tools of middle class, in spite of the fact that they are replaced by with perfect batteries.
Advantages of nickel-cadmium batteries are as follows:
The drawbacks they have are plenty:
Nevertheless, , nickel-cadmium and KB are reliable "workhorses", and are most often installed on a household class. In such conditions of exploitation, their qualities will be quite sufficient.
Nickel Metal Hydride batteries are an attempt by battery designers to get rid of from the main drawbacks of Ni-Cd .But it is not possible to say with full responsibility that this is a good step.
Advantages of such batteries:
Negative sides of similar accumulators:
In a word, the high-power on the such batteries looks unjustified. It is better to purchase or more cheap running version - nickel-cadmium , or no longer stint and choose screwdriver with lithium-ion battery.
By the way, nickel-metal hydride batteries and have not received much development, and on sale tool kits with them are rare enough - because of the low demand for them.
These are the latest and, respectively, advanced batteries for stand-alone power tools.
Advantages of these batteries are as follows:
There are several disadvantages:
When choosing the right model, it is best to purchase a kit that includes two batteries. So you can ensure the continuity of large-scale works - while one KB is on the screwdriver , the second gets charging. However, when using Ni-Cd batteries, it is always worthwhile to keep in mind the need to completely discharge them, so as not to cause a "memory effect".
Very often in the technical documentation of the product manufacturer indicates the average duration of charging of batteries - the less it is, the easier it will be to use the tool.
Well, those users, which do not want to communicate with the batteries, and of which does not frighten the power cord from the instrument, remains advise to buy a network model.
The performance of the tool does not suffer from this, but here's the convenience, of course, the is somewhat smaller .When you choose to pay attention only to the length of the cord - to its is sufficient for the specific conditions of the intended use.
This category of indicators can be attributed to the capabilities of the electric drive and gear transmission mechanism( reducer).
All these disadvantages is stripped of brushless engine with electronic control. The absence of an additional section of friction leads to a sharp increase in the productivity of the tool. So the . tests of similar models conducted by with completely identical power supplies showed that screwdriver with brushless engine performed almost three times as much as with a collector.
Some manufacturers( for example, DeWalt) decided to get rid of the engine body - all of its components are located directly in the body of the screwdriver. And this is not a trifle at all - a significant gain was obtained in the total mass of the instrument, which became much more convenient to work with.
So, if there is a choice between the conventional and brushless drive, it would be more reasonable for the to accept in favor of the latter. True, this affects the price of the instrument.
It can not be said that plastic gears are substandard, but still they have less service life than good metal ones. A deformation of even one tooth on any of gears entails jamming or complete destruction of the whole kinematic scheme of the reducer. So the choice is better to do in favor of metal.
The speed adjustment from of the zero to the maximum of the is performed by the by changing the pulling force of the trigger( key).For more comfortable execution of basic operations, you should choose screwdriver , which has the ability to switch the gearbox to high and low speed. Usually the switch is located on top of the case.
So, for work only with small fixture there is enough and 10 Nm, but it will be more likely an electric screwdriver. For the screwdriver to perform simple drilling operations, it is better to choose a model with a maximum force of at least 25 Nm. Accordingly, . in the case when more material is expected from the tool - for example, drilling wood with large diameter bits or metal, screw rt with crippling is selected with a torque of 36 Nm or more.
For many consumers, the torque values expressed in the are Newton-meters .They can say little. Therefore, in technical documentation screwdrivers , the limiting diameters of drill bits, - separately for metal and woodworking are usually specified additionally. This will make it much easier to determine the choice.
If the set force is exceeded, the is triggered by the stitch or slip clutch, and the excessive torque not the is transferred to the by the .
The digits on the scale show only the sequence number of the specific switch position as the torque increases, but are in no way connected( as some inexperienced users erroneously) with the fastener diameters. The symbol of the drill stands for the maximum torque required to drill.
Most modern screwdrivers are equipped with quick-action chucks, which allow to change bits or drills with .
Quick-release chucks can be single- and double-clutch.
In the double-clutch chuck, when installing and removing the tool, the lower clutch is held by hand, and the upper clamp is tightened or, conversely, released. With one-hull is still easier - the whole operation of is performed by with one-hand operation. However, in this case the screwdriver should be equipped with spindle lock function. Such a lock can be automatic, triggered when the rotation is stopped, or forced( there is a special button).
By the way, is mandatory when selecting screwdriver , it is necessary to clarify whether the tool has the option of forced spindle braking - when releasing the trigger, the rotation should immediately stop. Almost all modern tools are equipped with such a function, but if an outdated model, whose cartridge continues to rotate by inertia after a power failure, is not available, you should not purchase from its , as it will cause a lot of inconvenience.
Cam-operated cartridges, which require a special key for tightening, are rarely used with screwdrivers. The key has the property of forever disappearing somewhere during the operation, and the process of replacing the drill takes a lot of time and extra effort. However, , many masters include such a cartridge in their kit, since sometimes for drilling, requiring considerable effort, the force of the tightening of the socket can not be enough.
If the choice is made with calculation for the minimum dimensions of screwdriver and with its primary use for screwing fasteners, you can buy the model and without a cartridge - with an adapter for a ¼ "hexagon.
In this case, if you need to make any small boring operations, you can use a small cartridge that has an adapted hexagon shank.
Many models of modern screwdrivers are equipped with additional useful functions.
shock function. Many screwdrivers with shock function are equipped with an optional detachable lateral handle to accentuate the forward force when drilling.
Buying an like screwdriver, does still quite realistically imagine that it can cope with a brick wall or made by from some lightweight concrete( gas silicate).If it is required to drill holes in reinforced concrete structures, for example, in walls of or a panel house ceiling, it is better to have a perforator for such operations.
The activation of the pulse mode can be on the torque adjustment ring , or the can be executed as a separate push button, if necessary.
Another location of the lantern is at the bottom of the pistol grip. The stream of light is directed in this case so that it completely illuminates the working area from the bottom.
The convenience of this or that lighting scheme can be appreciated when selecting a tool.
But in any case, when evaluating the " pickup " screwdriver in the store, you should evaluate the location of the center of gravity of the tool - the offset forward or back gives the quick hand fatigue.
can be stuffed. Experienced masters advise to estimate the place of transition from the handle to the trigger - it should be with a smooth transition at an obtuse angle. A rectangular or acute-angled transition will cause the to rapidly fatigue the middle finger in large-scale work, and can even cause callus formation on the on it .
- The kit must include a charger with a power cord. Modern " chargers " is a well thought out electronic circuit that will not allow overheating of the battery, it will automatically turn off when the upper charging limit is reached.
As mentioned above, do not purchase screwdriver, equipped with only one battery.- this is extremely inconvenient in the work.
- The kit may include a flashlight - as additional lighting during operation or as a device for the required complete discharge of nickel-cadmium batteries.
- Often screwdrivers are equipped with special straps or even holster covers for easy tool placement on the master belt when performing work at height.
- To the bits supplied and drill bits m m Many professionals are very skeptical, preferring to purchase the necessary types separately. However, the leading manufacturers equip their sets with equipment of a sufficiently high level. True, the specification may not always be sufficient, and the need for additional purchase often arises.
- Professional screwdrivers can additionally be equipped with replaceable gear units. An example is the model " FESTOL C15 " .
In addition to the adapter for hexagon bits, a quick-action chuck can be mounted on the tool. In addition, in the kit, the is equipped with a gear reducer, which allows drilling by twisting the fasteners at an angle of 90 °. Another it is a replaceable nozzle - it is an eccentric that transmits rotation to a drill bit or bits with a displacement from the axis of the screwdriver. Very convenient function for working in a corner, such that the body of a conventional tool does not allow to achieve perpendicular force application.
However, the AS on similar kits is very high.
An important selection criterion should always be the manufacturer company and the availability in the specific region of the service of this brand.
But to buy a "cat in a sack", under the unknown delirium, most often of Chinese production - this is certainly a "lottery".It is possible that such screwdriver and will serve a lot, and will fully cope with the tasks assigned to it. However, , in case of failure to rely on any technical support or guarantee - it is not necessary. Yes, and with spare parts for self-repair can be a big problem.
And at the end of the publication - very volumetric and cognitive video lecture for the selection of the optimal screwdriver .