Magnetic base

A magnetic base is a magnetic fixture based on a magnet that can effectively be turned "on" and "off" at will; they are often used in optics and metalworking, e.g., to hold a dial indicator.

The vertical post, side arm (as shown in the image at right) and the dial indicator (not shown) are connected by two swivelling connectors. These connectors allow free movement of the arms so that the indicator can be presented to the work in a suitable orientation. The magnetic base may have a "V" cut into the bottom of the base or the back, this "V" allows the base to be attached to a round bar such as the column of a drill press.