The SMBN0613 block neodymium magnet is made from high performance N42 NdFeB, with Nickel coating. The dimension of this item is 3″ × 1/2″ × 1/8″ thick, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.0508125 lbs. It can pull up to 18.33 lbs steel. And the surface field is up to 1977 gauss.