The SMCN0312 cylinder neodymium magnet is made from high-performance N42 NdFeB, with Nickel coating. The dimension of this item is 1/4″ dia. × 1″ thick, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.0133125 lbs. It can pull up to 4.13 lbs steel. And the surface field is up to 6549 gausses.