We are doing a yard clean up and I was thinking about getting a 3’ magnet to drag the yard with. Lots of nails, screws, old welding rods laying all over and causing flat tire problems. I was thinking about attaching the magnet to a set of harrows (behind the harrows). It would pick up what was loosened when we drag. My question is: would the magnet loose some of its power if attached by metal brackets to the harrows? I figure there are lots of smart people hanging out here. I have done some googling but not getting much info. Any ideas?