An apparatus usable as a chucking device to temporarily couple two mechanical objects together. In one embodiment, the apparatus includes an arbor configured to receive an at least partially ferromagnetic object; and a magnet assembly. The magnet assembly includes multiple permanent magnets mounted in a soft ferromagnetic enclosure. The magnet assembly is rotatably coupled to the arbor such that the magnet assembly and the arbor are positionable relative to one another in locking and unlocking positions upon relative rotation therebetween. The magnet assembly is configured to exert a pulling force on the object in the locking position and a lesser force in the unlocking position.