The SMBN0474 block neodymium magnet is made from high-performance N42 NdFeB, with Nickel coating. The dimension of this item is 3/8″ length × 3/4″ width × 1/4″ thick, with step IN, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″ x ±0.004″. The weight of this super strong neodymium magnet is 0.01725 lbs. It can pull up to 13.01 lbs steel. And the surface field is up to 4528 gausses.