Drills are a very large family of power tools, the main purpose of which is to make holes in machinable materials: wood, steel, aluminum, plastics, etc., as well as in building materials (brittle). Due to having the hammer drilling function (mechanical impact), a distinction is made between hammer drills and non-percussion drills. Due to design reasons, there are also angle drills equipped with an angular gear and designed to work in hard-to-reach places. These machines are also divided due to the shape of their body, into pistol casing, "D" and "L" type, cross and angular.
Drilling machines consist of the following basic components: electric motor, cooling fan, gear (currently max. 2 gears) or angle gear (only angle drills), mechanical impact mechanism (only impact drills), switch for hammer and impact drilling functions ( only hammer drills), self-centering drill chuck in key or quick-clamping (keyless) versions, switch and electronic control systems (including speed regulation and stabilization), power cord, housing (1- or 2-part) with main and removable handle additional handle. In high-power models, anti-overload clutches are installed to increase work safety.
For drilling, twist drills (bits), twist, flat, stepped and percussive drills are used for drilling, countersinks, reamers, center and sedniks, hole saws, diamond bits, crowns with carbide teeth. For assembly - bits and sockets as well as adapter adapters. Drilling machines are also used to make small internal threads (usually up to M8) in steel and non-ferrous metals using taps mounted in special holders that protect them against breaking. In addition, very often these machines are used for mixing by means of mixers with hexagonal handles. Occasionally they are also used for grinding with flap wheels or points, abrasive papers and cloths. These power tools are often used to drive technical brushes during rust removal and cleaning of metal surfaces. Drilling machines can even mill hard alloy milling arbors adapted to work with a speed of approx. 4000 min-1. Important additional accessories for drills are drilling dust extraction systems or attachments with a vacuum cleaner stub, as well as drill stands intended for stationary drilling, enabling accurate drilling of larger diameters in wood, steel, aluminum, non-ferrous metals, cast iron, etc.
The main technical parameters of corded drills are: nominal power (max. 1300 W), useful power (730 W), supply voltage (230 V / 50 Hz), torque (maximum 101 Nm), rotational speed (max. 4000 min -1), impact frequency (58,900 min-1, only for hammer drills), maximum drilling diameter in steel (16 mm), maximum drilling diameter in wood (45 mm), maximum drilling diameter in masonry (24 mm), diameter range mounting in the drill chuck (up to 16 mm, usually up to 13 mm), diameter of the mounting neck (43 mm), weight of the device (2.6 kg).
Drilling machines have the following fields of application, listed below according to their degree of importance: hand-held drilling with solid bits or hole saws in machinable materials such as wood, steel, aluminum, non-ferrous metals, cast iron, etc .; hand-held drilling with hammer drill bits with cylindrical handle in stone, brick, masonry, light concrete; stationary drilling (very accurate using a drill stand) with solid drills or holesaws in machinable materials, such as wood, steel, aluminum, non-ferrous metals, cast iron, etc .; reaming and countersinking of holes; driving in / out screws, bolts, nuts; threading; mixing paints and mortars. Occasional applications nowadays include grinding, polishing, brushing with technical brushes, milling and driving attachments and other devices.
Today, drills are manufactured by AEG, Bosch, DeWALT, Fein, HiKOKI, Makita, Milwaukee and Metabo. The advantages of these power tools are handy, high accuracy and efficiency, as well as the possibility of stationary drilling with the use of a stand.
