Magnetic Flux Density (B) When a ferromagnetic or ferrimagnetic material is placed in an external magnetic field, its atomic magnetic moments tend to align with the applied field. This alignment creates an additional internal magnetic field, known as magnetization (M). The combined effect of the external magnetic field (H) and the magnetization (M) inside the material results in what we call magnetic flux density, symbolized as (B). In simple terms: (B) = The total magnetic field that the magnet actually

Surface Magnetic Field refers to the magnetic flux density measured at a specific point on the surface of a magnet. It is expressed in units of Gauss (Gs) or Tesla (T), where 1 T = 10,000 Gs. Because the magnetic field strength varies across different areas of a magnet’s surface, the value commonly referred to as the “surface magnetic field” usually represents the magnetic flux density at the center of the working surface of the magnet. Measuring Surface Magnetic Field