The SMBN0536 block neodymium magnet is made from high performance N52 NdFeB, with Nickel coating. The dimension of this item is 1″ × 1″ × 3/8″ thick, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.101875 lbs. It can pull up to 53.53 lbs steel. And the surface field is up to 4128 gausses.