This listing features 24mm+ OD NdFeB magnetic rings optimized for gear pumps, diaphragm pump rotors, and slotted motor speed measurement. Options include copper inner cores, axial magnetization, and unmagnetized blanks. Available in high-temp grades (40SH, 45H) resisting up to 150°C, with Epoxy coatings and strict ±0.1mm tolerances.
Note: Specific grades, geometries, and copper cores vary by exact PN. Please verify details before ordering.
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Understanding Our Parameter Table:

Magnetization method
(Ex. MT/Pole Count = 8 poles)
(Ex. MT/Pole Count = 2 poles)
(Ex. MT/Pole Count = 6 poles)
Parameter Table Terminology:
| No. | Item | Description | Notes |
|---|---|---|---|
| 1 | PN | Part Number | Every magnet/magnetic ring has a unique PN. Duplicate values are sometimes caused by differences in raw material grades. |
| 2, 3, 4 | O.D./I.D./T | The Magnetic Ring Dimensions | All dimensions in the table are in millimeters. O.D = Outer Diameter I.D = Inner Diameter T = Thickness |
| 5 | MT | Master-track Pole Count | For a magnetic ring with a single track, the Master-track represents the number of magnetic poles. For example, "10 poles" means 5 pole pairs. |
| 6 | NT | Nonius-track: Orbit with Fewer Pole Count | For a 2-track magnetic encoder ring, the Nonius-track typically has the lower pole count. The number of poles on the Nonius-track may sometimes be an odd number, such as 3 poles. |
| 5 | MATL | Magnetic Ring Material | There are various types of magnetic ring materials. Please refer to the FAQ at the bottom of the page. |
| 6 | SF | Surface Magnetic Field | This refers to the surface magnetic field strength. |
| 7 | MAG | Magnetization Method | Common magnetization methods are listed at the top of the page. |
| 8 | CMTS | Comments | This section provides information about the use, features, and other details of the magnetic ring. |
| PN | O.D | I.D | T | MAG | MT | SF | MATL | CMTS |
|---|---|---|---|---|---|---|---|---|
| R4163 | 24 | 0 | 3 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N35, nickel-plated sintered neodymium disc magnet for strong holding and attraction |
| R4670 | 24 | 0 | 15 | Axial | 2 | 464~488mT | Sintered NdFeB Magnets | Grade N48M, nickel-plated. Grade N48M, Ni-Cu-Ni plated; solid cylindrical sintered neodymium magnet for strong holding applications |
| R2317 | 24 | 5 | 3 | Radial | 2 | 100~500mT | Neodymium magnets | - |
| R1786 | 24 | 5 | 33 | Radial | 2 | 100~150mT | Neodymium magnets | Axial magnetization available. |
| R3784 | 24 | 6 | 4.8 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N50 sintered neodymium ring magnet for high magnetic force applications; axially magnetized |
| R5021 | 24 | 6.5 | 3 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N52, nickel-plated. Ring magnet with straight bore for holding and sensing applications; axially magnetized, nickel-plated |
| R3496 | 24 | 6.5 | 9.3 | Axial | 6 | 95~100mT | Injection molded ferrite magnets | For motor encoder sensing rings; injection-molded ferrite, axially magnetized |
| R0258 | 24 | 7 | 2 | Axial | 2 | 100-150mT | Bonded neodymium magnets | - |
| R0582 | 24 | 8 | 5 | Radial | 12 | 120mT | Injection molded ferrite magnets | The inside of the magnetic ring is made of copper. |
| R0581 | 24 | 8 | 9.5 | Axial | 6 | 60-70mT | Injection molded ferrite magnets | Hall effect sensor magnetic ring |
| R0580 | 24 | 8 | 10 | Radial | 10 | 70-76mT | Injection molded ferrite magnets | Magnetic ring for DC geared motor |
| R0259 | 24 | 8 | 20 | Outer,Radial | 4 | 100-150mT | Bonded neodymium magnets | - |
| R0063 | 24 | 8.85 | 8 | Radial | 20 | 170-175mT | Bonded neodymium magnets | Motor speed measuring magnetic ring |
| R0578 | 24 | 8.9 | 8 | Radial | 20 | 170-175mT | Bonded neodymium magnets | Magnetic ring for slotted motor speed measurement |
| R3446 | 24 | 8.9 | 8 | Outer,Radial | 8 | 70~76mT | Injection molded ferrite magnets | For DC gear motor encoder speed-sensing magnets; injection-molded ferrite, radially magnetized |
| R4527 | 24 | 10 | 1.5 | Axial | 2 | 158.2mT | Sintered NdFeB Magnets | Grade N38H, zinc-plated sintered neodymium ring magnet for encoder and sensor applications |
| R0579 | 24 | 10 | 8 | Radial | 20 | 170-175mT | Bonded neodymium magnets | Magnetic ring for slotted motor speed measurement |
| R3447 | 24 | 10 | 8 | Outer,Radial | 8 | 70~76mT | Injection molded ferrite magnets | For DC gear motor encoder speed-sensing magnets; injection-molded ferrite, radially magnetized |
| R4511 | 24 | 10 | 10 | Axial | 2 | 356.3mT | Sintered NdFeB Magnets | Grade N38, zinc-plated ring magnet for shaft-mounted encoder and sensor applications; sintered neodymium with center hole |
| R1869 | 24 | 10 | 32 | Radial | 2 | 100~150mT | Neodymium magnets | - |
| R5087 | 24 | 10 | 32 | Radial | 2 | 250~650mT | Sintered NdFeB Magnets | For industrial radial magnetization applications; sintered neodymium ring magnet |
| R1936 | 24 | 10 | 36 | Radial | 2 | 100~150mT | Neodymium magnets | |
| R2109 | 24 | 10 | 38 | Radial | 2 | 100~850mT | Neodymium magnets | Tolerace ±0.1mm |
| R2110 | 24 | 10 | 39 | Radial | 2 | 100~1200mT | Neodymium magnets | Tolerace ±0.1mm |
| R2491 | 24 | 10 | 40 | Radial | 2 | 100~500mT | Neodymium magnets | - |
| R4528 | 24 | 12 | 0.98 | Axial | 2 | 62mT | Sintered NdFeB Magnets | Grade N42H, NiCuNi-plated sintered neodymium ring for high-performance magnetic assemblies |
| R3592 | 24 | 12 | 3 | Radial | 12 | 90~300mT | Bonded neodymium magnets | Bonded NdFeB ring for Hall sensor, motor, and robot applications; radially magnetized with 12 poles |
| R1947 | 24 | 12 | 18 | Radial | 2 | 100~500mT | Neodymium magnets | |
| R1946 | 24 | 12 | 38 | Radial | 2 | 100~150mT | Neodymium magnets | |
| R5022 | 24 | 12.5 | 2 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N52, nickel-plated. Ring magnet with straight bore; axially magnetized, nickel-plated |
| R2319 | 24 | 12.5 | 5 | Radial | 2 | 100~500mT | Neodymium magnets | - |
| R3902 | 24 | 12.5 | 5 | Radial | 2 | 250~650mT | Sintered NdFeB Magnets | Grade N52, nickel-plated sintered NdFeB ring magnet; radially magnetized for encoder applications |
| R2318 | 24 | 14 | 3 | Radial | 2 | 100~500mT | Neodymium magnets | - |
| R5023 | 24 | 14 | 4 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N52, nickel-plated. Ring magnet with straight hole for adsorption and sensing; axially magnetized, nickel-plated |
| R3705 | 24 | 16 | 3 | Axial | 2 | 80~650mT | Neodymium magnets | Ring magnet for encoder or magnetic coupling use; axially magnetized, nickel-plated |
| R1283 | 24 | 16 | 5 | Radial | 2 | 100-120mT | Sintered neodymium magnets | - |
| R1710 | 24 | 16 | 5 | Radial | 2 | 68~78mT | Neodymium magnets | - |
| R3525 | 24 | 16 | 5 | Radial | 12 | 80-90mT | Ferrite magnets | For motor encoder speed-sensing rings; sintered ferrite, radially magnetized |
| R3895 | 24 | 16 | 5 | Axial | 2 | 80~650mT | Neodymium magnets | Axial ring magnet for encoder and sensor applications; sintered rare-earth neodymium |
| R4671 | 24 | 16 | 5 | Axial | 2 | 247.7mT | Sintered NdFeB Magnets | Grade N38, nickel-copper-nickel plated; ring magnet for experimental magnetic levitation |
| R3908 | 24 | 16 | 10 | Radial | 2 | 80~650mT | Neodymium magnets | Radial ring magnet for encoder and sensor applications |
| R4147 | 24 | 16 | 10 | Axial | 2 | 80~650mT | Neodymium magnets | Ring magnet for encoder and sensor applications; nickel-plated neodymium |
| R3889 | 24 | 16 | 13 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N35, nickel-plated ring magnet for encoder and sensor applications |
| R4685 | 24 | 16.5 | 2 | Axial | 2 | 102.4mT | Sintered NdFeB Magnets | Grade N38, zinc-plated sintered neodymium ring for encoder and sensor applications |
| R3913 | 24 | 17 | 1.5 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N35H, nickel-plated ring magnet; axially magnetized |
| R2862 | 24 | 17 | 40 | Outer,Radial | 4 | 100~350mT | Bonded neodymium magnets | External Skewed / Skew Magnetization |
| R2968 | 24 | 17 | 40 | Outer,Radial | 2 | 100~350mT | Bonded neodymium magnets | - |
| R2863 | 24 | 17 | 60 | Outer,Radial | 4 | 100~350mT | Bonded neodymium magnets | External Skewed / Skew Magnetization |
| R2969 | 24 | 17 | 60 | Outer,Radial | 2 | 100~350mT | Bonded neodymium magnets | - |
| R3591 | 24 | 18 | 6 | Radial | 12 | 85~100mT | Bonded neodymium magnets | Bonded neodymium encoder ring for Hall-effect sensing; radially magnetized with 12 poles |
| R1711 | 24 | 19 | 2 | Radial | 2 | 22~32mT | Neodymium magnets | - |
| R3787 | 24 | 19 | 4 | Radial | 2 | 120mT | Bonded neodymium magnets | Bonded neodymium encoder ring for Hall sensors and robotics; radially magnetized |
| R4074 | 24 | 19 | 5 | Axial | 2 | 80~650mT | Neodymium magnets | Ring magnet for general holding and assembly applications; sintered neodymium |
| R0583 | 24 | 19 | 30 | Radial | 10 | 85-100mT | Bonded neodymium magnets | Magnetics encoder ring |
| R3688 | 24 | 19.3 | 1.5 | Axial | 2 | 80~650mT | Neodymium magnets | Ring magnet for encoder applications; axially magnetized, two-pole |
| R0959 | 24 | 19.4 | 2.5 | Radial | 2 | 85-100mT | Bonded neodymium magnets | - |
| R1229 | 24 | 19.6 | 2 | Radial | 2 | 100-120mT | Sintered neodymium magnets | High temperature resistance 150° |
| R5024 | 24 | 20.4 | 2.5 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N52, nickel-plated. Ring magnet with straight bore for adsorption and sensing; axially magnetized, nickel-plated |
| R0587 | 24.2 | 12.1 | 22.8 | Radial | 4 | 300-310mT | Bonded neodymium magnets | Magnetic rotor for magnetic pump |
| R0585 | 24.2 | 12.4 | 10 | Radial | 8 | 300-310mT | Bonded neodymium magnets | Magnetic rotor for gear pump |
| R2992 | 24.2 | 12.4 | 14.5 | Outer,Radial | 4 | 100~350mT | Bonded neodymium magnets | - |
| R2993 | 24.2 | 12.4 | 14.5 | Outer,Radial | 8 | 100~350mT | Bonded neodymium magnets | - |
| R0586 | 24.2 | 12.4 | 17.5 | Radial | 4 | 300-320mT | Bonded neodymium magnets | Magnetic rotor for diaphragm pump motor |
| R3003 | 24.2 | 12.4 | 22.8 | Outer,Radial | 4 | 100~350mT | Bonded neodymium magnets | - |
| R3004 | 24.2 | 12.4 | 22.8 | Outer,Radial | 8 | 100~350mT | Bonded neodymium magnets | - |
| R2966 | 24.2 | 16.6 | 15 | Unmag | 0 | 100~350mT | Bonded neodymium magnets | - |
| R0898 | 24.4 | 14.2 | 15 | Radial | 4 | 380-435mT | Ferrite magnets | Multi-pole magnetic ring for refrigerator compressor motor |
| R1355 | 24.4 | 20.4 | 13 | Unmag | 0 | 300-500mT | Neodymium magnets | Not magnetized, Self-magnetization needed, Applicable to motor magnetic ring, coating: Epoxy, Grade: 45H |
| R1356 | 24.4 | 20.4 | 26 | Unmag | 0 | 300-500mT | Neodymium magnets | Not magnetized, Self-magnetization needed, Applicable to motor magnetic ring, coating: Epoxy, Grade: 45H |
| R1357 | 24.4 | 20.4 | 39 | Unmag | 0 | 300-500mT | Neodymium magnets | Not magnetized, Self-magnetization needed, Applicable to motor magnetic ring, coating: Epoxy, Grade: 45H |
| R3803 | 24.5 | 0 | 3.5 | Axial | 2 | 250~650mT | Sintered NdFeB Magnets | Grade N42 sintered neodymium disc magnet, axially magnetized, for high-force holding applications |
| R4742 | 24.5 | 0 | 5 | Axial | 2 | 191~239mT | Sintered NdFeB Magnets | Grade N35H, nickel-plated. Grade N35H, zinc-plated sintered neodymium disc magnet for high-temperature applications up to 120°C |
| R5025 | 24.5 | 6 | 2 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N52, nickel-plated. Ring magnet with straight hole for adsorption and sensing; axially magnetized, nickel-plated |
| R4154 | 24.5 | 12 | 2 | Axial | 2 | 80~650mT | Neodymium magnets | Ring magnet for encoder and sensor applications; zinc-plated |
| R4238 | 24.5 | 13 | 5 | Axial | 2 | 80~250mT | Injection molded neodymium magnets | Injection-molded ring magnet for pneumatic cylinder and encoder applications |
| R4246 | 24.5 | 16 | 4 | Axial | 2 | 80~650mT | Neodymium magnets | Ring magnet for general holding and assembly applications; zinc-plated sintered NdFeB |
| R4081 | 24.5 | 16 | 5 | Axial | 2 | 80~650mT | Neodymium magnets | Ring magnet for holding and magnetic applications; sintered neodymium |
| R3081 | 24.5 | 16.5 | 15 | Unmag | 0 | 100~350mT | Bonded neodymium magnets | - |
| R4069 | 24.5 | 17.5 | 3.5 | Axial | 2 | 250~650mT | Sintered NdFeB Magnets | Grade N38, zinc-plated sintered neodymium ring magnet for holding and magnetic applications |
| R4144 | 24.5 | 17.5 | 3.5 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N38 neodymium ring magnet for holding and magnetic applications |
| R3987 | 24.5 | 18.5 | 3.5 | Axial | 2 | 80~650mT | Neodymium magnets | Grade N35, nickel-plated sintered neodymium ring magnet |
| R4676 | 24.6 | 0 | 5 | Axial | 2 | 196.8~207.4mT | Sintered NdFeB Magnets | Grade N38, NiCuNi-plated sintered neodymium coin magnet for multi-purpose use |
| R0590 | 24.6 | 12 | 26 | Radial | 8 | 160-170mT | Ferrite magnets | Miniature water pump rotor (with magnets) |
| R4525 | 24.6 | 15.5 | 2 | Axial | 2 | 143.4mT | Sintered NdFeB Magnets | Grade N35, zinc-plated sintered neodymium ring magnet for encoder and motor applications |
| R4682 | 24.7 | 12 | 3.75 | Axial | 2 | 262mT | Sintered NdFeB Magnets | Grade N50, zinc-plated sintered NdFeB ring for high-remanence magnetic applications |
| R4681 | 24.8 | 0 | 3.5 | Axial | 2 | 142~150mT | Sintered NdFeB Magnets | Grade N38, NiCuNi-plated sintered neodymium disc magnet for general holding and industrial applications |
| R4253 | 24.8 | 13.5 | 3 | Axial | 2 | 80~650mT | Neodymium magnets | Ring magnet for encoder and sensor applications; sintered neodymium |
| R1223 | 24.8 | 22.8 | 10 | Radial | 12 | 60-70mT | Bonded neodymium magnets | Motor magnetic ring |
| R0591 | 24.95 | 12 | 7 | Axial | 4 | 110mT | Injection molded ferrite magnets | - |
| R2831 | 24.96 | 21.13 | 15 | Outer,Radial | 24 | 100~350mT | Bonded neodymium magnets | OD tolerance ±0.04mm, ID tolerance ±0.03mm |
| R2830 | 24.96 | 21.13 | 40 | Outer,Radial | 8 | 100~350mT | Bonded neodymium magnets | OD tolerance ±0.04mm, ID tolerance ±0.03mm |
FAQs
Please send the SKU number and quantity of the magnetic rings you want from the list.
Your salesperson will send you a price quote and payment options (T/T 100% upfront or credit card 100% upfront).
- In-stock items: Ship immediately after payment.
- Out-of-stock items: Ship within 30 days after payment.
Our magnetic rings have a key benefit: transparent costs for molds and magnetizing coils. We don't charge extra for these.
For small sample orders (around 10 pieces), this stock is usually leftover from larger production runs. Please pay quickly to secure your stock. We don't start production for small orders; it's not cost-effective for us.
We usually start production for orders over 2k-10k pieces to manage costs. If your order is small and not confirmed quickly, you might miss out on current stock.
Sizes: All lengths are in millimeters (mm) by default.
Number of poles:
- The Master-track refers to the main magnetic track's pole count on a ring magnet. Most ring magnets, like those for motors or incremental encoders, have only one magnetic track.
- However, absolute encoder ring magnets or encoder ring magnets with marker points also have a Nonius-track. This means they have two magnetic tracks, as shown in the picture.
- Ferrite magnets are also called sintered ferrite or hard ferrite magnets. They look and are made like ceramics, so some call them ceramic magnets.These magnets are cheap to make in large amounts, even though the mold costs are high. They are very good at resisting rust and high temperatures, up to 250℃.Ferrite magnets are accurate and low-cost for encoders. But, they can break easily if shaken a lot, like in outdoor robots. For those, Vulcanized rubber magnet material is more stable.
- Injection molded ferrite magnets are made by mixing ferrite magnetic powder with plastic binders like Nylon (PA6 or 12) or PPS. This mixture is then injection molded, meaning it's shaped using a mold.These magnets can even be molded directly onto a metal shaft. They can work in temperatures up to 150°C.
Bonded neodymium magnets are made by mixing neodymium magnetic powder with a binder.
Simply put, they are injection molded, which means they contain a binder. About 80% of the magnet is neodymium powder, and the remaining 20% is binder.
Their benefits include high dimensional accuracy, great design flexibility, and good mechanical strength.
Injection molded neodymium magnets are made by mixing neodymium magnetic powder with thermoplastic. This mix is then injection molded. These magnets are stronger than injection molded ferrite magnets.
Injection molded neodymium magnets can be made into many shapes. They can be small or irregular. You can magnetize them with multiple poles or complex patterns. They are also very accurate and consistent in shape.
These magnets can be molded directly onto motor cores or metal shafts. This saves assembly costs. They are seen as a stronger option than injection molded ferrite magnets. They can work in temperatures up to 180℃.
These magnets are injection molded neodymium or ferrite magnets that include a metal carrier. Please see the picture below:
Sintered NdFeB magnets are also called Sintered Neodymium magnets. These are the strongest known permanent magnets. They are made from neodymium (Nd), iron (Fe), boron (B), and other rare earth elements.
These magnets create very strong magnetic fields and stay magnetic at room temperature. They can be made into many shapes. This makes them great for many uses, especially for high-end commercial motors.
Sintering is how they are made. Powdered materials are heated until they merge. This process makes the magnets stronger and more effective.
However, these magnets can corrode easily and are affected by high temperatures. So, they are usually coated (often with a nickel-copper-nickel layer) to protect them. Adding heavy rare earth elements also helps them resist higher temperatures.
- Vulcanized rubber magnet material is made when magnetic powder is added to rubber during a process called vulcanization. This process changes the rubber's structure, making it much stronger, more elastic, and more stable.Vulcanized rubber magnets are often used for magnetic targets on sports robots. They are flexible and don't break easily from shocks.
- Rubber magnets are made from magnetic powder mixed with synthetic rubber. They are formed by extrusion, calendering, or injection molding. You can make them into strips, rolls, sheets, blocks, rings, and many other shapes. Their main advantages are that they are flexible and can be made into various shapes.However, their disadvantage is that they are not very strong (they don't have high remanence) compared to Neodymium magnets. For encoders, regular rubber magnets can't meet high precision needs. They are only good for single-track incremental encoders.
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margaret.martone –
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gary –
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