The SMBN0449 block neodymium magnet is made from high-performance N42 NdFeB, with Nickel coating. The dimension of this item is 1/2″ length × 1/2″ width × 1/4″ thick, with step IN, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.01575 lbs. It can pull up to 12.22 lbs steel. And the surface field is up to 4594 gausses.