The SMBN0418 block neodymium magnet is made from high performance N42 NdFeB, with Nickel coating. The dimension of this item is 3/8″ length × 3/8″ width × 1/4″ thick, with step IN, magnetized through thickness, with tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.008625 lbs. It can pull up to 7.62 lbs steel. And the surface field is up to 5196 gausses.