The SMBN0457 block neodymium magnet is made from high performance N42 NdFeB, with Nickel coating. The dimension of this item is 1/2″ × 1/2″ × 2″ thick, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.136875 lbs. It can pull up to 22.29 lbs steel. And the surface field is up to 6535 gausses.