These neodymium channel magnets have two cou ntersunk holes on the steel channels instead of the magnets which probably will crack when tightening up the screws. When the countersunk holes are on the magnets you will get into a dilemma between the enough torque for the screws and not cracking the magnets. An alternative solution as a gun or magazine holder for gun collections. Also good for door magnets or magnetic latches. This neodymium channel magnet is made of a super strong neodymium magnet encased inside a chrome plated steel channel that triples the holding force to 45 lbs which is 15 pounds stronger than an equivalently sized standard channel magnet! At the same time the steel channel also protects the magnet from being damaged during day to day use. Each channel magnet measures 2" in length 1/2" wide and 1/4" with two holes on each side meant for #6 wood screws. It's perfect for use as an extra heavy duty magnet holders to keep tools and hardware in one place cabinet latch or even as an extra secure mount for moveable lighting or cameras. This channel magnet has two #6 countersunk holes on each end to allow for flush installation to maximize holding power. These cabinet magnets are popular with cabinet makers school teachers machinists magicians students on a gate hobbyists inventors technicians diyers mars rovers (yup up there) craft magnets uses hobbies therapy storage experiments science fairs labs garages schools offices magic shops garages fasteners hinges parking lots material handling catches latches laundry rooms industrial & scientific applications tool hangers & are great door magnets for use on pantry doors plantation shutters cupboard in closets in the garage for holding tools outdoor decorations towel hangers knife holders as drapery hardware any closure refrigerator magnets scrap books drawers kitchen cabinets recoup storage space on a shutter theater props ceiling & wall treatments gun mounts string magnets displays trade shows retrieval