Product Overview
Ring Ferrite Magnets
Ring ferrite magnet (ceramic ring magnet) is a type of permanent ferrite magnet with a circular ring structure, usually with a through hole in the center. It is made of strontium ferrite or barium ferrite as the main raw material, through molding, sintering and other mature processes. As a cost-effective magnetic component, it is widely used in various low-to-medium power scenarios due to its unique structural advantages and stable performance.
The core structure of ring ferrite magnet is a circular ring with a central through hole, which can be divided into solid ring type and hollow ring type according to the hole diameter ratio. Its outer diameter, inner diameter and thickness are the three key size parameters, which can be customized according to application needs. The ring structure ensures uniform magnetic field distribution, and the central through hole is convenient for installation and fixing with shafts, bolts or other components, making it suitable for rotating parts such as motor rotors.
Ningbo Vanguard Technologies provides a complete range of ring ferrite magnets in multiple standard grades and customized sizes. Strict in-process control ensures tight dimensional tolerance and consistent magnetic output for seamless rotor installation and motor assembly. Every piece is inspected through full magnetic performance testing and dimensional checking to guarantee long-term operational stability in various working conditions.
We offer both standard catalogue dimensions and fully customized ring profiles, OD, ID and axial length. Fast sample delivery within 10–15 days and stable mass production lead times are available. Our products can be supplied as bare magnets or integrated rotor components, meeting diverse OEM and ODM demands for industrial and commercial motor applications.
Quick View
Ring Ferrite Magnet Selection Snapshot
Y25-Y40
Available Grade Range
Common ferrite grades including Y25, Y30, Y30BH, Y35, Y40 and C5/C8 series for ring and rotor applications.
Stable Cost
Mass Production Advantage
A cost-effective choice for high-volume speakers, meters, rotors and appliance assemblies.
OD / ID
Ring Geometry Control
Outer diameter, inner diameter, thickness, chamfer, concentricity and magnetization direction can be customized.
10-15 Days
Prototype Sample Lead Time
Fast sampling after grade, drawing, tolerance and magnetization direction are confirmed.
Ferrite Grade Selection Guide
1Drawing ReviewOD, ID, thickness, tolerance
2Grade MatchFlux, coercivity, application target
3Tooling PlanPressing, sintering, grinding
4MagnetizationAxial, radial, multi-pole
5InspectionFlux, size, polarity, appearance
Key Applications
Rotors for household fan motors, toy motors, and small water pump motors. Their ring structure and central through hole fit perfectly with motor shafts, providing stable rotational power and meeting the low-power operation needs of small motors at low cost.
Loudspeakers & Headphones
Magnetic components for small loudspeakers, desktop speakers, and entry-level headphones. Ring ferrite magnets generate a uniform magnetic field to drive the voice coil, ensuring clear sound output while controlling production costs.
Power Meters & Electrical Instruments
Magnetic cores for household power meters, ammeters, and voltmeters. Their stable magnetic performance ensures accurate measurement of electrical parameters, and the ring structure is easy to install inside instruments.
Auxiliary magnetic components for low-precision proximity sensors and position sensors. Ring ferrite magnets provide a stable magnetic field to trigger sensor signals, suitable for light industrial and household sensing scenarios.
Toy & Educational Equipment
Magnetic components for magnetic educational toys, science experiment kits, and small toy motors. They are safe, non-toxic, moderately magnetic, and easy to assemble, fitting the low-cost mass production needs of the toy industry.
Medical Auxiliary Instruments
Auxiliary magnetic parts for small medical equipment (e.g., portable blood pressure monitors, small diagnostic tools). Their stable magnetic performance and corrosion resistance suit clean, humid medical environments.
Grade & Magnetic Properties
Standard grades for ring ferrite magnets. All values at 20 °C. Values are typical; exact grade selection is confirmed per application, working temperature, magnetic circuit, shaft assembly and cost target.
|
Standard |
Grade |
Remanence |
Coercivity |
Intrinsic Coercivity |
Max. Energy Product |
|
Br |
Hcb |
Hcj |
(BH)max |
|
mT |
kG |
kA/m |
kOe |
kA/m |
kOe |
kJ/m3 |
MGOe |
|
Chinese Standard |
Y8T |
200-235 |
2.0-2.35 |
125-160 |
1.57-2.01 |
210-280 |
2.64-3.52 |
6.5-9.5 |
0.8-1.2 |
|
Y10T |
200-235 |
2.0-2.35 |
128-160 |
1.61-2.01 |
210-280 |
2.64-3.52 |
6.4-9.6 |
0.8-1.2 |
|
Y20 |
320-380 |
3.2-3.8 |
135-190 |
1.70-2.39 |
140-195 |
1.76-2.45 |
18.0-22.0 |
2.3-2.8 |
|
Y22H |
310-360 |
3.1-3.6 |
220-250 |
2.76-3.14 |
280-320 |
3.52-4.02 |
20.0-24.0 |
2.5-3.0 |
|
Y23 |
320-370 |
3.2-3.7 |
170-190 |
2.14-2.39 |
190-230 |
2.39-2.89 |
20.0-25.5 |
2.5-3.2 |
|
Y25 |
360-400 |
3.6-4.0 |
135-170 |
1.70-2.14 |
140-200 |
1.76-2.51 |
22.5-28.0 |
2.8-3.5 |
|
Y26H |
360-390 |
3.6-3.9 |
220-250 |
2.76-3.14 |
225-255 |
2.83-3.20 |
23.0-28.0 |
2.9-3.5 |
|
Y26H-1 |
360-390 |
3.6-3.9 |
200-250 |
2.51-3.14 |
225-255 |
2.83-3.20 |
23.0-28.0 |
2.9-3.5 |
|
Y26H-2 |
360-380 |
3.6-3.8 |
263-288 |
3.30-3.62 |
318-350 |
4.00-4.40 |
24.0-28.0 |
3.0-3.5 |
|
Y27H |
370-400 |
3.7-4.0 |
205-250 |
2.58-3.14 |
210-255 |
2.64-3.20 |
25.0-29.0 |
3.1-3.6 |
|
Y28 |
370-400 |
3.7-4.0 |
175-210 |
2.20-2.64 |
180-220 |
2.26-2.76 |
26.0-30.0 |
3.3-3.8 |
|
Y28H-1 |
380-400 |
3.8-4.0 |
240-260 |
3.02-3.27 |
250-280 |
3.14-3.52 |
27.0-30.0 |
3.4-3.8 |
|
Y28H-2 |
360-380 |
3.3-3.8 |
271-295 |
3.41-3.71 |
382-405 |
4.80-5.09 |
26.0-30.0 |
3.3-3.8 |
|
Y30 |
370-400 |
3.7-4.0 |
175-210 |
2.20-2.64 |
180-220 |
2.26-2.76 |
26.0-30.0 |
3.3-3.8 |
|
Y30BH |
380-390 |
3.8-3.9 |
223-235 |
2.80-2.95 |
231-245 |
2.90-3.08 |
27.0-30.0 |
3.4-3.8 |
|
Y30H-1 |
380-400 |
3.8-4.0 |
230-275 |
2.89-3.46 |
235-290 |
2.95-3.64 |
27.0-32.0 |
3.4-4.0 |
|
Y30H-2 |
395-415 |
3.95-4.15 |
275-300 |
3.46-3.77 |
310-335 |
3.90-4.21 |
27.0-32.5 |
3.4-4.1 |
|
Y32 |
400-420 |
4.0-4.2 |
160-190 |
2.01-2.39 |
165-195 |
2.07-2.45 |
30.0-33.5 |
3.8-4.2 |
|
Y32H-1 |
400-420 |
4.0-4.2 |
190-230 |
2.39-2.89 |
230-250 |
2.89-3.14 |
31.5-35.0 |
4.0-4.4 |
|
Y32H-2 |
400-440 |
4.0-4.4 |
224-240 |
2.81-3.02 |
230-250 |
2.89-3.14 |
31.0-34.0 |
3.9-4.3 |
|
Y33 |
410-430 |
4.1-4.3 |
220-250 |
2.76-3.14 |
225-255 |
2.83-3.20 |
31.5-35.0 |
4.0-4.4 |
|
Y33H |
410-430 |
4.1-4.3 |
250-270 |
3.14-3.39 |
250-275 |
3.14-3.46 |
31.5-35.0 |
4.0-4.4 |
|
Y34 |
420-440 |
4.2-4.4 |
200-230 |
2.51-2.89 |
205-235 |
2.58-2.95 |
32.5-36.0 |
4.1-4.5 |
|
Y35 |
430-450 |
4.3-4.5 |
215-239 |
2.70-3.00 |
217-241 |
2.73-3.03 |
33.1-38.2 |
4.2-4.8 |
|
Y36 |
430-450 |
4.3-4.5 |
247-271 |
3.10-3.41 |
250-274 |
3.14-3.44 |
35.1-38.3 |
4.4-4.8 |
|
Y38 |
440-460 |
4.4-4.6 |
285-305 |
3.58-3.83 |
294-310 |
3.69-3.90 |
36.6-40.6 |
4.6-5.1 |
|
Y40 |
440-460 |
4.4-4.6 |
330-354 |
4.15-4.45 |
340-360 |
4.27-4.52 |
37.5-41.8 |
4.7-5.3 |
|
American Standard |
C1 |
230 |
2.3 |
148 |
1.86 |
258 |
3.5 |
8.36 |
1.05 |
|
C5 |
380 |
3.8 |
191 |
2.4 |
199 |
2.5 |
27 |
3.4 |
|
C7 |
340 |
3.4 |
258 |
3.23 |
318 |
4 |
21.9 |
2.75 |
|
C8 / C8A |
385 |
3.85 |
235 |
2.95 |
242 |
3.05 |
27.8 |
3.5 |
|
C8B |
420 |
4.2 |
232 |
2.913 |
236 |
2.96 |
32.8 |
4.12 |
|
C9 |
380 |
3.8 |
280 |
3.516 |
320 |
4.01 |
26.4 |
3.32 |
|
C10 |
400 |
4 |
280 |
3.52 |
284 |
3.57 |
30.4 |
3.82 |
|
C11 |
430 |
4.3 |
200 |
2.512 |
204 |
2.56 |
34.4 |
4.32 |
|
C12 |
400 |
4 |
290 |
3.65 |
318 |
4 |
32 |
4 |
Typical Physical Properties (All Sintered FERRITE Grades)
|
Parameter |
Unit |
Value |
|
Density / ρ |
g/cm3 |
4.9-5.1 |
|
Vickers Hardness / HV |
– |
400-700 |
|
Compression Strength |
N/mm2 |
680-720 |
|
Coefficient of Thermal Expansion / α |
10-6/°C |
C⊥: 10 |
|
C∥: 15 |
|
Electrical Resistance / ρ |
mΩ·cm |
1 x 1010 |
|
Thermal Conductivity / k |
W/(cm·°C) |
0.029 |
|
Tensile Strength / σ |
Pa |
34 x 106 |
|
Modulus of Elasticity / λ |
Pa |
1.8 x 1011 |
|
Flexural Strength / σ |
Pa |
62 x 106 |
|
Compression Strength |
Pa |
895 x 106 |
|
Poisson’s Ratio / v |
– |
0.28 |
Magnetization Orientations Available
Dimension Capability
Ring magnets are defined by outer diameter (OD), inner diameter (ID), and axial length (L). Standard tolerance is ± 0.10 mm on all dimensions; tight-tolerance ± 0.03 mm is available on request. Concentricity, roundness, chamfer, countersunk holes, slots and matched-set sorting can be controlled for precision assembly.
|
Dimension |
Minimum |
Maximum |
Standard Tol. |
|
Outer Diameter (OD) |
3 mm |
300 mm |
± 0.10 mm |
|
Inner Diameter (ID) |
1 mm |
140 mm |
± 0.10 mm |
|
Axial Length (L) |
1 mm |
80 mm |
± 0.10 mm |
Design Support
How to Specify Ring Ferrite Magnets
Grade Selection
Common grades include Y25, Y30, Y30BH, Y35, Y40 and C5/C8 series. Higher grades improve flux output, while high-coercivity grades are used where demagnetization resistance is more important.
Ring Geometry
OD, ID, axial length, wall thickness, concentricity, roundness and chamfer should be confirmed together, especially for shafts, speaker assemblies and rotating parts.
Cost-Effective Design
Ferrite rings are ideal when corrosion resistance, stable supply, large-volume production and competitive unit cost are more important than rare-earth magnetic strength.
Custom Manufacturing
Available Custom Features
Ring, washer, tube, thin ring, thick-wall ring, countersunk ring, slotted ring, segmented ring and precision-ground bore.
Speaker, motor rotor, sensor ring, instrument, coupling, toy motor and low-cost magnetic assembly.
Axial, radial, diametrical, multi-pole, matched set and fixture-specific magnetization.
Stable voice-coil field, repeatable rotor output, sensor triggering and easy assembly identification.
Grinding, chamfering, cleaning, polarity marking, adhesive backing, plastic housing and custom export packing.
Automated assembly, speaker production, motor rotor bonding and high-volume OEM supply.
Production Control
Manufacturing & Quality Assurance
Ring ferrite magnets are produced from ferrite powder through wet or dry pressing, magnetic-field orientation, high-temperature sintering, core drilling or forming, ID/OD grinding, cleaning, magnetization and final inspection. Stable tooling and powder control help keep bore accuracy and magnetic output consistent in mass production.
Magnetic Inspection
Br, Hcb, Hcj, (BH)max, surface flux, pull force, pole direction, multi-pole distribution and batch consistency can be tested according to customer specification.
Dimensional Inspection
OD, ID, axial length, wall thickness, concentricity, roundness, parallelism, chamfer, hole position and surface condition are checked before packing.
Supply Support
Sample development, pilot production, mass production, magnetic report, dimensional report, RoHS/REACH documents and custom packing are available.
Fast Quotation
Information Needed for Fast Quotation
For faster review, please provide drawing or sample, OD, ID, axial length, tolerance, grade or target surface flux, magnetization direction, chamfer or hole requirement, working environment, sample quantity and annual volume. If the grade is not fixed, we can recommend a ferrite grade based on performance and cost target.
Frequently Asked Questions
What grades are available for ring ferrite magnets?
Common grades include: Y30, Y35, Y40, C5, C8, higher grades provide stronger magnetic performance.
What is the minimum order quantity for custom ring magnets?
For custom geometry, samples can be arranged from as few as 50–200 pieces. Mass-production MOQ is typically 1000–10000 pieces per specification, though this is flexible depending on magnet size and grade. Contact us to discuss your project volume.
Can you supply ring magnets already assembled into a rotor?
Yes. Vanguard provides integrated rotor assembly services — including magnet bonding, balancing, and shaft press-fitting — as part of our Magnetic Systems product line. We can supply bare ring magnets or complete rotor sub-assemblies depending on your manufacturing flow.
Do you provide material certifications and test reports?
Full material certificates (chemical composition, magnetic test data) are provided with each shipment as standard. ROHS, REACH, and conflict-mineral declarations are available on request.
What is the lead time for ring ferrite magnets?
Prototype samples: 10–15 working days. Mass-production orders: 25–35 working days depending on grade, coating, and quantity. Rush sampling may be available — please inquire.
