A power tool is a mechanized tool powered by an electric motor or electromagnet, which drives a working head through a transmission mechanism. It is a hand-held tool that uses a low-power electric motor or electromagnet as the power source to drive the working head through a transmission mechanism.
In 1895, Germany manufactured the world's first DC electric drill. Its casing was made of cast iron, and it could drill 4mm holes in steel plates. Subsequently, three-phase industrial frequency (50Hz) electric drills appeared, but the motor speed did not exceed 3000 r/min.
In 1914, power tools driven by single-phase series-wound motors appeared, with motor speeds exceeding 10,000 r/min.
In 1927, medium-frequency power tools with a power supply frequency of 150-200Hz appeared. They combined the advantages of high speed from single-phase series-wound motors with the simple and reliable structure of three-phase industrial frequency motors, but their use was limited due to the need for medium-frequency current.
Common power tools include electric drills, electric grinders, electric wrenches and screwdrivers, electric hammers and impact drills, concrete vibrators, and electric planers.
