China Neodymium And Ferrite Magnets Manufacturer & Supplier 
In the fields of motors, sensors, encoders, etc., the professional term "inner diameter 4-pole magnetized magnetic ring" is often encountered. Many customers may wonder what "inner diameter 4-pole magnetization" is when they first come into contact with it? What is the difference between it and a regular magnetic ring? What sizes do you have for me to choose from?
The so-called inner circle 4-pole magnetic ring refers to the inner surface of the magnetic ring undergoing multipole magnetization treatment, forming four alternating magnetic poles (N, S, N, S) on the inner circumference. The magnetic field is mainly concentrated inside the magnetic ring, which can provide stable and accurate magnetic signals for Hall sensors, magnetic encoders, etc.
The following picture is a schematic diagram of the magnetization of OD 4-pole magnetic ring
The biggest difference between a 4-pole magnetized ring magnet with an inner circular surface and a regular magnetic ring is the distribution of magnetic poles. Ordinary magnetic rings are usually magnetized with a single pair of poles, with the outer circle or end face appearing as an N pole and an S pole. The magnetic field distribution is relatively simple and suitable for ordinary adsorption, positioning, and other scenarios. The internal 4-pole magnetic ring is magnetized alternately with four magnetic poles (N-S-N-S) in the inner circle of the magnetic ring, forming a multipolar rotating magnetic field in the inner hole area, which has the characteristics of more uniform magnetic field distribution and more obvious signal changes.
As a professional supplier of motor magnets, our company has a large supply of multi pole magnetic ring specifications and can also provide suitable solutions according to your project application. The specifications of the inner circle 4-pole magnetized magnetic ring are as follows: D19.5 * d12.7 * 12.5mm,、D11.9 * d10.1 * 1.7mm/1026Gs,、D27.2 * d24.2 * 19mm/、 D18.6*d15.6*9.5mm、D28x24.8x8.5mm、D21.2*d19.2*9.8mm、D48*d42.8*13mm、D27.2*d24.2*30.5mm, D27 * d24 * 32mm
Related inner diameter multipole magnetized ring magnets;
Ceiling fan magnetic ring internal 10 poles 65.5 x 57.5 x 20 mm
Radially inner 10 poles fan motor bonded magnet ring 56x53x10mm