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How to choose a good screwdriver, features of this product
The screwdriver is a compact, most often self-contained power tool designed to tighten bolts and screws. In the arsenal of a home master, this is perhaps the fourth most important power tool after a perforator, drill and grinder. And although the drill can also be used to tighten and loosen the screws, it is still not able to replace the screwdriver. However, like a screwdriver drill. This is due to the design features of a screwdriver. We will talk about the features. But at the same time we will learn how to choose a good screwdriver and not fall for marketing tricks.
Content
Features of a screwdriver device
The main elements of a screwdriver are:
- rechargeable battery (the higher the capacity, the longer the battery life of the tool);
- housing;
- start and reverse button;
- electric motor;
- gearbox;
- coupler;
- cartridge for attaching nozzles.
What is the feature of this power tool? What is so different about a drill? The main difference is the coupler. In fact, it is a mechanical limiter of the twisting force. On all screwdrivers it is adjustable. As a rule, about 16 positions of force adjustment are allowed (maybe more). The essence of his work is that when the set force is exceeded and the result is achieved, the protective mechanism is triggered (ratchet).
For a better understanding, take the screw tightening example. The drill will screw it in until we release the button. If the screw is stuck or it completely entered the head, and we did not have time to release the button, then, as a rule, this ends by licking the edge of the nozzle or grooves in the screw head. In a similar situation, with the correct adjustment of the screwdriver coupler, the ratchet will slip the chuck will stop. This is especially true when working with brittle materials, for example, when installing drywall.
All other elements of a screwdriver are similar to a drill, except that the design of the cartridge is somewhat different and the characteristics are lower. But, this is not a fundamental difference. Therefore, we can draw the following conclusion: only an ordinary screwdriver or wrench can replace a screwdriver to assemble structures, especially a fine one, and our hand.
How to choose the right screwdriver
So we decided to buy a screwdriver. But which one? The choice is really great. Both firms and models. In order not to get confused in all the variety, we outline the main selection criteria:
- instrument category (household or professional);
- battery; - rotation frequency;
- maximum torque.
Choosing a screwdriver category is very simple. If used, the tool will be from time to time, two three times a month, then it is necessary to select among household models of screwdrivers. It just doesn't make sense to pay more for a professional model. The latter are designed for constant load, and accordingly everything is done there with a margin of safety.
Batteries are represented by two types: nickel cadmium and lithium-ion. There was a third version of Ni-MH, but due to its shortcomings, it has practically sunk into oblivion. As for the choice between Ni-Cd and Li-Ion, everything, in fact, comes down to the budget for the purchase. The latter battery option is significantly more expensive. True and has several advantages:
- does not have a memory effect, which significantly reduces the battery capacity;
- self-discharge is several times smaller than Ni-Cd analogues (over 12 months, losses amount to no more than 20% of capacity);
- do not require a full battery discharge in order to put on charge, which increases user comfort;
- have a smaller size and weight, which also affects the usability of the tool.
The speed is selected depending on the goals. If you are not going to drill with a screwdriver, then 500 600 rpm is enough for screws and bolts.
When using a cordless screwdriver for domestic use, it is not at all necessary to take a professional model with a torque of 160 N * m. Is that to brag to a neighbor. For most screws and self-tapping screws, 15 N * m is enough.
These are the main selection criteria. Therefore, when a consultant in a store persuades to take a household model of a screwdriver with the function of drilling with battle, do not buy. In household screwdrivers, as a rule, plastic parts are installed. And the manufacturer does not hide it. Due to this, the price is much less than the pros of analogues. And how long will the plastic planetary gear serve when drilling with battle? A couple of times, and then to the service center.
Also, do not overpay for more sophisticated advertised models that do not realize even half of their characteristics in everyday life.
Useful little things
In addition to the main criteria for choosing an electric screwdriver, several very useful and convenient functions can also be distinguished. Their presence, if it affects the price, is insignificant. But the level of comfort of using the tool increases significantly. These nuances include:
- Ergonomics, i.e. how convenient the instrument lies in the hand. When using a screwdriver twice a month, the indicator is not critical, but for a professional, yes.
- The presence of a hand strap. It may seem commonplace. But when you are under the ceiling and with one hand you hold a sheet of drywall and the other screwdriver, you understand the whole depth of the manufacturer’s concern for the client.
- The presence in the kit of an angular nozzle, which is able to rotate at an angle of 360 *. Without it, in inaccessible places simply can not get, for example, when repairing a washing machine.
- The presence of a metal cap cartridge will significantly extend its service life. Although if you work carefully, you can do it.
- The charger for the screwdriver should have a clear indication of the end of the battery charge, this is especially important when using Ni-Cd batteries.
- The presence of lighting is important, the available lighting in the room is not always enough.
All other functions, such as a display screen, are at the discretion of the buyer. They, as a rule, do not have special significance, and to tighten / twist the screws certainly do not help. But here, as they say, they don’t argue about tastes.
