Abstract: A compact device employing the controlled use of explosives to quickly and easily remove tapered keys, as typically lodged into a notched shaft for purposes of attaching machinery such as a sprocket, gear, flywheel or coupling to a shaft. The invention consists of an explosion-resistant plunger which fits flush into an explosion-resistant block frame. The plunger covers, as a lid, a compartment in the frame into which a predetermined amount of gunpowder or similar explosive is placed. The invention is positioned between the block of a tapered key and the hub of the machinery from which the key is to be removed. A length of fuse is inserted into the compartment through an aperture in the frame for ignition of the explosive, such that the resulting explosion forces the invention plunger against the hub and frame in the opposite direction against the block of the tapered key, in turn loosening the tapered key from the hub.