The SMBN0642 block neodymium magnet is made from high performance N52 NdFeB, with Nickel coating. The dimension of this item is 4″ × 3″ × 2″ thick, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 6.50625 lbs. It can pull up to 1013 lbs steel. And the surface field is up to 5336 gausses.