What exactly is magnetic drilling equipment?
More or less a question for mechanics and machinists and an easy one. If you've ever busted a head stud off on a Jaguar, you know of the evils needed to get the remainder out of the block. Lots of methods out there, but aside from electrostatic erosion, most methods involve using a drill.

This drilling machine is magnetic because the base is a very strong magnet allowing this unit to be a magnetically attached drill press or boring machine. Clean the engine block deck off till shiny and you have a perfectly flat surface which you need to get a perfectly straight drilling operation. Get alignment on the drill bit, engage the base so the magnetic field locks it down to the engine block and commence drilling out the stud so you can start messing with your chosen method of repairing the damage.

Another example from Milwaukee Tools