Neodymium rod magnets are most commonly magnetized along their length. With axial magnetization, the north and south poles are located on the two circular end faces, concentrating the magnetic output at both ends.
This configuration is suitable for end-to-end attraction and assemblies in which one or both end faces interact with steel components or other magnets.
Rod magnets can also be magnetized across their diameter. With diametrical magnetization, the poles are positioned on opposite sides of the cylindrical surface rather than at the two ends. This arrangement provides magnetic output from the sides and can be used in sensing, positioning, and rotating structures where polarity is required around the circumference.
The length-to-diameter ratio also influences the magnetic behavior of axially magnetized rod magnets. A greater length relative to diameter generally results in a higher permeance coefficient (Pc) and a more favorable operating point. However, magnetic force at the end faces also depends on pole area, air gap, magnet grade, mating steel, and the surrounding magnetic circuit. Increasing the length alone does not produce a proportional increase in holding force.
Magnetization direction should therefore be specified together with diameter, length, and the intended installation arrangement. Axially and diametrically magnetized rod magnets with the same dimensions produce substantially different magnetic distributions and are not normally interchangeable.
SDM supplies custom Neodymium rod magnets in different diameters, lengths, material grades, coatings, dimensional tolerances, and magnetization directions. Chamfers and polarity markings can also be added when required.
For a quotation, please provide the diameter, length, material grade, coating, magnetization direction, quantity, and available drawings.
