01 · Overview
About Disc Magnets
Disc magnets are cylindrical magnets commonly specified by diameter and thickness. Their field and holding force depend on aspect ratio, magnetization, gap and the surrounding steel. Medical-device uses require qualification of the finished device.
02 · Drawing review
Drawing review and documented scope
- Diameter, thickness and magnetization reviewed against the drawing
- Grade and series confirmed for the intended geometry
- Coating stack and acceptance tests agreed for the exposure
03 · Typical Use Cases
Where Disc magnets go to work
Hall sensor targets
Holding and clamping fixtures
Scientific instrument positioning
Medical-device mechanism design studies
04 · Dimensions & Tolerances
Drawing dimensions and tolerances
| Parameter | Specification |
|---|---|
| Typical dimensions | Diameter and thickness specified on the drawing |
| Tolerances | Finished dimensions and coating allowance agreed per drawing |
Tighter spec?
Send your drawing with the critical surfaces called out. We will confirm the dimensions, production route and inspection requirements for your part.
05 · Grade references
Grade references for Disc
N35
80°C classN35 reference: 33–36 MGOe at 20°C, with a nominal 80°C temperature class.
Reference; drawing review required
N38
80°C classN38 reference: 36–39 MGOe at 20°C, with a nominal 80°C temperature class.
Reference; drawing review required
N42
80°C classN42 reference: 40–43 MGOe at 20°C, with a nominal 80°C temperature class.
Reference; drawing review required
N45
80°C classN45 reference: 43–46 MGOe at 20°C, with a nominal 80°C temperature class.
Reference; drawing review required
N48
80°C classN48 reference: 45–48 MGOe at 20°C, with a nominal 80°C temperature class.
Reference; drawing review required
06 · Related Applications
Related Applications
Medical Devices
NdFeB design considerations for medical equipment mechanisms, sensors and permanent-magnet MRI systems.
Industrial Automation
NdFeB magnets for stepper motors, servo drives, linear actuators, magnetic couplings, and factory automation equipment across European and North American manufacturing.
Frequently Asked Questions
What disc magnet grades can Mainrich quote?
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Mainrich’s sintered NdFeB range is N30 to N56, with no AH grades. The top grade depends on the temperature series: N56, N54M, N52H, N52SH, N50UH and N45EH. Grades up to N52SH can be made without a Chinese export licence, so we offer those first; UH and EH grades need a licence, applied for per order. The actual grade, series and disc geometry need drawing review. Reference grades outside that range are educational; they are not a Mainrich disc supply offer.
How is the surface field of a disc magnet specified?
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Specify the measurement point, probe standoff, magnetization direction, temperature and surrounding magnetic circuit. A diameter, thickness and grade alone do not define one surface-field value. BHmax is energy product, not the field at the probe.
What coating should I use for disc magnets in medical applications?
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Parylene is one candidate barrier coating. Biological evaluation, coating integrity, exposure and sterilization testing must address the finished part and device. A coating designation does not establish implant suitability, hermeticity or MR safety.
Next step
Request a Quote for Disc Magnets
Share dimensions, quantity, grade target and operating conditions. We respond within 1 business day. The production route and acceptance requirements are confirmed during drawing review.