Switchable Magnet

A switchable magnet, also called a magnetic base, is a metalworking fixture built from one or more permanent magnets arranged so an operator can turn the external magnetic field on or off. Rotating the internal magnet redirects the flux either inward, leaving the surface inert, or outward across an air gap, where it grips a ferrous workpiece firmly enough to hold it in place. Metalworkers use switchable magnets to attach items to metal surfaces during fabrication, measurement, and assembly without a permanent fixture, and the same mechanism is also used in optics, lifting, and robotics. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/