The SMBN0442 block neodymium magnet is made from high-performance N42 NdFeB, with Nickel coating. The dimension of this item is 1/2″ × 1/2″ × 1/32″ thick, magnetized Through Thickness, with the tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.00211875 lbs. It can pull up to 1.31 lbs steel. And the surface field is up to 738 gauss.