Hydraulic-based generator systems come in two basic configurations: those with the hydraulic generator mounted on the base machine and those with the gen set attached to the magnet. This article focuses on the latter type, generically called hydraulic magnets. Although the vast majority of these magnets get installed on excavators, you can use these hydraulic systems wherever you’ve got hydraulic power and need a magnet, including on truck cranes, backhoes, skid-steers, rough-terrain forklifts, and wheel loaders. This technology allows users to easily and quickly move the magnet assembly from one machine to the other, so the demolition contractor can share one hydraulic magnet among several excavators rather than install a magnet generator on each machine. The amount of flow a hydraulic magnet requires in terms of gallons per minute depends on the size of the generator and the amount of energy it must generate to power the magnet. Typically these generators need to spin in the 3,000 rpm range. A general rule is 2 hp of machine power for every kilowatt the magnet needs, so a 5 kW hydraulic magnet needs at least 10 hp of machine power, and so on.