Just because a magnet is rated to 2,400 pounds doesn’t necessarily mean it could pick up a pontoon boat by locking onto a single screw. If that were the case, no amount of human strength would be capable of extracting metal from that magnet. Instead, the pull force of a magnet is calculated by how much force is required to detach a magnet in “ideal conditions,” as Nachtwey says. That means pulling the magnet straight up from a solid, ½-inch-thick steel plate on which the entire magnetic face is fixed.