Grinders
Introduction
An angle grinder, also known as a side grinder or disc grinder, is a handheld power tool used for cutting, grinding, and polishing various materials including metal, stone, concrete, and masonry.[1] It features a rotating abrasive disc or wheel attached at a right angle to the motor, enabling precise and efficient material removal in industrial, construction, and fabrication settings.[2]
The angle grinder was invented in 1954 by the German company Ackermann + Schmitt (now FLEX-Elektrowerkzeuge GmbH), with the launch of the DL 9 model as the first high-speed version, revolutionizing abrasive cutting by allowing handheld operation at speeds up to 9,000 RPM.[3] Over the decades, the tool has evolved significantly, incorporating innovations such as lightweight designs in the 1960s (e.g., the ZL 108 model), vibration-reducing handles in the early 2000s (e.g., the L 3406 VRG), and brushless motors with cordless battery options by the 2010s and 2020s (e.g., the L 125 18.0-EC in 2017 and LBP 125-15 18-EC in 2024).[3] These advancements have made angle grinders more ergonomic, portable, and versatile for professional use.
Primarily employed in metalworking for tasks like weld seam removal, rust elimination, and edge deburring, angle grinders are also essential in construction for cutting tiles, concrete, and rebar, as well as in polishing surfaces to achieve smooth finishes.[2] They come in various types, including corded electric models for continuous power, cordless battery-powered variants for mobility, pneumatic air-driven units for precision in confined spaces, and variable-speed options to accommodate different materials and applications.[2] Disc sizes typically range from 4 to 9 inches, with power outputs from 500 to 2,500 watts, allowing adaptability across trades.[2]
Due to their high rotational speeds—often exceeding 10,000 RPM—angle grinders pose significant safety risks, including disc fragmentation, kickback, and flying debris, which account for numerous workplace injuries annually.[1] Standard safety features include spindle locks for disc changes, electronic overload protection, and anti-restart mechanisms, while users must employ personal protective equipment such as goggles, gloves, and dust masks, along with proper guards and training to mitigate hazards.[2] Regulatory bodies like OSHA emphasize regular inspections and adherence to manufacturer guidelines to ensure safe operation.[1]