The SMDN0143 disc neodymium magnet is made from high-performance N42 NdFeB, with Black epoxy coating. The dimension of this item is 3/4″ dia. × 1/8″ thick, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.0149375 lbs. It can pull up to 9.76 lbs steel. And the surface field is up to 2087 gausses.