The SMBN0416 block neodymium magnet is made from high performance N52 NdFeB, with Nickel coating. The dimension of this item is 3/8″ × 3/8″ × 1/8″ thick, magnetized Through Thickness, with tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.0047625 lbs. It can pull up to 6.43 lbs steel. And the surface field is up to 3798 gausses.