The SMBN0520 block neodymium magnet is made from high-performance N52 NdFeB, with Nickel coating. The dimension of this item is 1″ × 1/2″ × 1/2″ thick, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.0675 lbs. It can pull up to 38.39 lbs steel. And the surface field is up to 5884 gausses.