The Difference Between
The surface magnetic field of NdFeB magnets is much lower than that of remanent magnetic field. Residual magnetization and surface magnetic field, one is the material property, the other one is the product characteristic.The two are related,the relation is like specific gravity and weight.Surface magnetic field relates with remanent magnetism and shape.And magnetism also depends on size.
The thinner the NdFeB magnets is, the lower the surface magnetic field, minimum to zero. The thicker the NdFeB magnets, the higher the surface magnetic field, up to half of the remanent magnetism.