20mm x 3mm Hole 3mm Strong N52 Countersunk Ring Rare Earth Neodymium Magnet
20mm x 3mm Hole 3mm N52. Super Strong Rare Earth Magnet Countersunk Rings. Magnets are made of a brittle material. These magnets are not as strong as steel. They are more like a brittle ceramic. If you let two magnets slam together, they can crack and break.