The electric drill is a drilling machine using electricity as power. It is a conventional product among electric tools, and also the electric tool product with the largest demand. The annual production and sales volume accounts for 35% of China's electric tools.

       The main specifications of electric drills are 4, 6, 8, 10, 13, 16, 19, 23, 32, 38, 49mm, etc. The number refers to the maximum diameter of the drill bit drilling on the steel with a tensile strength of 390N/mm2. For non-ferrous metals, plastics and other materials, the maximum drilling diameter can be 30-50% larger than the original specification.

       The birth of the world's electric tools began with the electric drill products. In 1895, Germany developed the world's first DC electric drill, which weighed 14 kg. The shell was made of cast iron, and only 4 mm holes could be drilled on the steel plate. Subsequently, a three-phase power frequency (50Hz) electric drill appeared, but the motor speed failed to exceed 3000 r/min.

       In 1914, the electric drill driven by single-phase series motor appeared, and the motor speed reached 10000 r/min.

       In 1927, the medium frequency electric drill with power supply frequency of 150~200Hz appeared. It not only has the advantages of high speed of single-phase series motor, but also has the advantages of simple and reliable structure of three-phase power frequency motor. However, its use is limited due to the need for medium frequency current power supply.

       In the 1960s, there appeared a battery type electric drill without power line using nickel cadmium battery as power supply. By the middle and late 1970s, due to the lower battery price and shorter charging time, this electric drill was widely used in Europe, America and Japan.

       At first, the electric drill used cast iron as its shell, and then changed to aluminum alloy as its shell. In the 1960s, thermoplastic engineering plastics were applied to electric drills and double insulation was realized.

       In the 1960s, electronic speed regulating electric drills also appeared. This kind of electric drill uses thyristor and other components to form an electronic circuit. The speed is adjusted according to the different depths of the switch button pressed, so that the electric drill can select different speeds according to the different objects to be processed (such as different materials, drilling diameter, etc.) during use.

       The working principle of the electric drill is that the motor rotor of the electromagnetic rotary or electromagnetic reciprocating small capacity motor does magnetic field cutting and works. The driving mechanism drives the operating device to drive the gear to increase the power of the drill, so that the drill can scrape the surface of the object and penetrate the object better.