The SMBN0458 block neodymium magnet is made from high-performance N42 NdFeB, with Nickel coating. The dimension of this item is 9/16″ × 9/16″ × 9/16″ thick, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.04825 lbs. It can pull up to 23.66 lbs steel. And the surface field is up to 5754 gausses.