Neodymium ring magnets can be axially, diametrically, radially, or multipole magnetized. Even when the dimensions and material grade remain the same, different pole arrangements can produce very different magnetic characteristics. Magnetization direction is therefore one of the most important factors when selecting ring magnets for a specific design.
The magnetization direction determines where the north and south poles are located, which surfaces provide the main magnetic output, and how the magnetic output is distributed around Neodymium ring magnets. Even when ring magnets have the same dimensions and material grade, different pole arrangements can produce very different magnetic characteristics.
Neodymium ring magnets are available with axial, diametrical, radial, multipole, and skewed magnetization patterns. Depending on the pattern, the main magnetic output may be provided by the flat faces, the outer diameter, the inner diameter, or opposite circumferential sides of the ring.
The appropriate magnetization pattern depends primarily on where the magnetic interaction is required. Axial magnetization is generally selected when the flat faces interact with mating components or magnetic circuits. Diametrical magnetization provides one pair of opposite poles across the diameter, while diametrical multipole magnetization distributes alternating poles around the outer or inner diameter. Radial magnetization is different, with opposite polarities located on the inner and outer diameter surfaces.
Pole number, pole pitch, working air gap, and the position of surrounding components affect the field distribution and usable magnetic output. For diametrical, multipole, and skewed designs, specifying the magnetization direction by name alone may not provide enough information. Drawings should clearly indicate the pole arrangement, working surface, number of poles, polarity, and skew angle where applicable.
Ring dimensions, wall thickness, material grade, and magnetizing fixture capability may affect the feasibility of complex magnetization patterns. These factors should therefore be reviewed early in the development of custom Neodymium ring magnets.
SDM supplies custom Neodymium ring magnets according to customer drawings and application requirements. Available options include material grade, dimensions, dimensional tolerances, coating, magnetization pattern, polarity marking, and inspection requirements. For close-fitting or rotating assemblies, concentricity, runout, flatness, perpendicularity, chamfers, and coating thickness may also need to be specified when they affect alignment, working air gap, or assembly accuracy.
When requesting a quotation, please provide the ring dimensions, material grade or operating temperature, coating, quantity, tolerances, and magnetization requirements. For motor, sensor, and multipole designs, drawings showing the pole arrangement, working air gap, mating components, and required inspection method can help us evaluate the project more accurately.
