This sample is a round magnet with hole with outer diameter more than 3 inches, made of rare earth neodymium material, the type of hole is countersunk screw hole, which can be better mounted or passed through some objects, the specific outer diameter is 80mm, the inner hole is 10mm, the thickness is 5mm, the edge of the table magnetic strength is higher than 2500 gauss, or we can do the adjustment of the size, performance, plating and so on, according to your actual needs.
Actual measurement of magnetic field strength on the surface of 80x5x10mm countersunk hole neodymium magnetic ring;
Collection of articles on round countersunk magnets;
Countersunk Hole Magnet Ring Outdoor Applications
8-25mm Round Countersunk Hole Magnet Gauss and Pull Force
Why are countersunk hole magnets mostly rare earth neodymium?