The SMDN0057 disc neodymium magnet is made from high performance N42 NdFeB, with Nickel coating. The dimension of this item is 3/8″ dia. × 3/32″ thick, magnetized through thickness, with tolerance of ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.00280625 lbs. It can pull up to 2.78 lbs steel. And the surface field is up to 2952 gausses.