The SMDN0163 Disc neodymium magnet is made from high-performance N42 NdFeB, with Nickel coating. The dimension of this item is 13/16″ dia. × 2/10″ thick, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.028125 lbs. It can pull up to 18.22 lbs steel. And the surface field is up to 2914 gausses.