Correct choice of screwdriver

Before anyone who independently repairs the apartment, garage, summer residence, sooner or later there is such a problem as the choice of a screwdriver. Today, the market offers a large selection of these convenient cordless electrical tools. Some put a nozzle to work with screws on the drill, but this is not always a convenient replacement, especially if you need to work the whole working day. A good cordless screwdriver has many necessary functions, which can not be replaced with any nozzles.

In order to choose the screwdriver was correct, you need to determine its criteria. The most important thing is to establish the degree of frequency of using the instrument. It is necessary to estimate, what operations will be carried out and how many times a day the instrument will be used without interruption. If the intensity is close to professional, then the choice of a screwdriver should be stopped on stamps similar to Bosh and Makita.

What characteristics of the instrument should you pay attention to first? This voltage, capacity and speed. The main part of the screwdriver, which allows it to work without a power source, is a battery. Its main characteristics are voltage and capacity, the first is measured in volts (V), and the second in amperes / hour (Ah). The voltage indicator is the capacity of the battery, and the capacity is the operating time after charging. For long-term operation, rechargeable batteries with a capacity of 1.3 Ah and higher, and power from 12 V and above are suitable. Buy better two at a time. One works until it is completely discharged, the other is charged, and it's better to charge it completely, not partially. In this mode, it will last much longer.

As for speed, it is better to stop the choice of a screwdriver on a two-speed tool. Low speed at high power, as a rule, is used for the twisting procedure, and high speed for drilling.

In inexpensive models there is no "stop" button. In the more expensive it is. If you press it, the screwdriver stops and does not rotate, which allows you to change the nozzles. Well, if you can set the torque stage. This will allow the screwdriver to automatically stop and do not twist the screws.

When choosing a screwdriver for a house, you need to be sure that it will withstand a fall from a two-meter height, because modern models have a sufficient limit of strength. Care of the tool is simple: you need to lubricate and clean the cartridge from time to time, avoiding the ingress of moisture, debris, sand or dust. It is important to ensure that the screwdriver does not overheat. If he "does not pull", you need to reduce the speed or apply a more powerful tool.

The choice of battery screwdriver also implies the choice of the type of battery. The market offers NiMH (nickel-metal hydride) NiCd (nickel-cadmium), and Li-Ion (lithium-ion).

NiCd has undeniable advantages, and there are three of them: cheapness, the highest number of recharges, respectively, the longest period of validity and the largest amount of current given out. The disadvantage is the "memory effect", a quick failure with incomplete discharge and charging. Keep these batteries is recommended in a discharged form at plus temperature. NiMH batteries, on the other hand, are recommended to be stored in a charged state.

The Li-Ion battery has such a disadvantage as aging, even if it is not used. For two years, most of the capacity of the battery is lost.

Today, there are models of screwdrivers that can operate on different types of batteries.

The most toxic is the production of nickel-cadmium batteries. On the territory of the European Union, their production is prohibited. More new and less toxic and safe for the environment is the production, and then the utilization of nickel-metal hydride batteries.