The SMSN0748 SPHERE neodymium magnet is made from high performance N42 NdFeB, with Nickel coating. The dimension of this item is 5/8″ diameter, with tolerance of ±0.004″. The weight of this super strong neodymium magnet is 0.034625 lbs. It can pull up to 10.24 lbs steel. And the surface field is up to 8815 gauss.