China Neodymium And Ferrite Magnets Manufacturer & Supplier 
In Hall-effect encoders, the dimensions, material and number of magnetic poles of the magnetic ring directly affect the encoder’s detection accuracy and stability. To assist customers with product selection, we have compiled the dimensions of magnetic rings for three commonly used materials and eight models of 2.5 mm-thick Hall-effect encoders.
Firstly, sintered ferrite magnetic rings are suitable for standard Hall-effect encoders, position detection, motor speed measurement and other applications, offering good value for money.
Recommended size: D13 x d9 x 2.5 mm (axially magnetised), D16 x d12 x 2.5 mm (axially magnetised), D21.6 x d14.8 x 2.5 mm (axially magnetised)
Bonded neodymium-iron-boron magnetic rings offer superior magnetic performance to sintered ferrite and are suitable for high-resolution angular detection, servo motors, robotic joints, motor feedback systems and other applications requiring high encoding accuracy.
Recommended dimensions: D52 x d47 x 2.5 mm
The accompanying image shows are multi-pole injection-moulded neodymium magnetic ring
In addition, there are injection-moulded ferrites, which can be moulded into complex shapes; as they possess a certain degree of toughness, they are less prone to breakage when mounted on a shaft, ensuring more stable operation.
Recommended dimensions: D9.5 x d3.2 x 2.5 mm (radial 4-pole)、D16 x d3.1 x 2.5 mm (single-sided 6-pole), D18 x d2.25 x 2.5 mm (single-sided 32-pole), D18 x d1.97 x 2.5 mm (single-sided 24-pole)
In addition to the specifications listed above, we can also customise magnetic rings for Hall effect encoders to meet your specific requirements. If you are looking for 2.5 mm thick magnetic rings suitable for Hall effect encoders, please do not hesitate to contact us.
Selection of relevant magnets;
Diametrically Magnetized Disc Magnets 2.5mm Thick For Encoder Chips