Screwdriver — almost indispensable tool DIY. During repair work screwdriver helps: it can be used to collect furniture and install interior doors, strengthen the construction of plasterboard, skirting boards. How to choose a screwdriver. he served for a long time, will tell the country of the Soviets.

Today, the market of building materials and tools offers a huge number of models of screwdrivers from different manufacturers. The characteristics of the models presented on the market depend on the choice of the screwdriver.

Screwdrivers are the battery and network. Screwdriver, working from the network, has in its design a transformer that converts alternating current into a constant one, and therefore the weight of such models is higher than that of rechargeable batteries. The disadvantages of network screwdrivers include the limitations of their use, because because of the power cord to use a screwdriver in hard-to-reach places is not always possible.

To choose screwdriver battery, you should pay attention to the type of the battery. There are screwdrivers with batteries metal-hybrid, nickel-cadmium, lithium-ion. The standard nickel-cadmium battery lasts an average of 1000 charges, metal-hybrid batteries are designed for approximately 500 charges. Lithium-ion batteries are considered the most reliable.

Metal-hybrid and nickel-cadmium batteries are subject to the so-called memory effect, when the capacity of the battery decreases with each new charge, if before the battery was not fully discharged. Lithium-ion batteries are free of this drawback, but nevertheless, they have not yet gained widespread popularity.

By the way, it is best to choose a screwdriver with replaceable battery included. The presence of removable battery allows you to avoid downtime: while the screwdriver is running on one battery, the second charging.

An important feature of leggings is their torque. For domestic use, usually enough torque of 10-15 Nm. Professional models have a torque of up to 130 Nm and can be used for drilling hard surfaces. If the screwdriver is supposed to be used quite often, then a model with a high torque will be preferable.

The frequency of rotation of the working shaft of the screwdriver  can range from 400-500 rpm for amateur models and up to 1200-1300 rpm for professional. Frequencies of 400-500 rpm will be enough for screwing screws, screws. A higher speed is required for boring work. You can choose a screwdriver with several speeds.

The number of steps for adjusting the torque you have to select the model of the screwdriver, cartridge type, grade a screwdriver — all these are also important characteristics of this tool. For example, the higher the number of stages of adjustment of the torque, the easier it is to manage so-called tightening force: all the screws and the screws are screwed down strictly to the required depth. A package of additional attachments makes the drill more functional.

To choose a screwdriver, be sure to try it. You should hold the chosen model in your hands, checking whether the screwdriver is comfortable in the hand, or if the hand is too quickly tired. An important role is played by the balance of the instrument, as well as the ergonomic design.

To choose a screwdriver correctly  - the task is simple enough if you know the basic characteristics of this power tool and accurately imagine the tasks that will be performed with it. Good luck with your choice!