This is a simple remix of the official Multiboard 20mm Big Bolt (https://thangs.com/designer/Multiboard/3d-model/20%20mm%20Big%20Thread%2C%20Plain%20Head%2C%20Bolt-974417) retrofitted for a 16x16 cylindrical magnet ([https://www.magnet4sale.com/27-lb-pull-n35-neodymium-disc-magnet-16x16mm-rare-earth-magnet/ - although it actually measures 15.8mm, so I made the insert 16.0mm; YMMV.

This allows panels to be mounted to metal surfaces, including wire shelf racks, with a very decent holding power. As a bonus, enough magnetism is present on the top side of the bolt to hold small tools and the like in place. You will have about 13mm of offset from the mounting surface.