The SMBN0500 BLOCK neodymium magnet is made from high performance N42 NdFeB, with Nickel coating. The dimension of this item is 1″ × 1/4″ × 1/4″ thick, magnetized Through Thickness, with tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.0169375 lbs. It can pull up to 13.15 lbs steel. And the surface field is up to 4871 gauss.