The SMDN0102 disc neodymium magnet is made from high performance N42 NdFeB, with Nickel coating. The dimension of this item is 9/16″ dia. × 1/32″ thick, magnetized Through Thickness, with tolerance of ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.00210625 lbs. It can pull up to 1.31 lbs steel. And the surface field is up to 729 gauss.