01 · Overview
About Arc Segment Magnets
Arc segments are separate magnets assembled around a rotor or housing. Their geometry and magnetization can be selected for the pole layout. Compare segment positioning, adhesive joints and retention with a one-piece ring against the same motor requirements; construction alone does not establish torque ripple or efficiency.
02 · Drawing review
Drawing review and documented scope
- Send chord or inner/outer radius, arc angle and axial length for drawing review
- Orientation, pole pattern and retention requirements reviewed together
- Grade, coating stack and finished dimensions confirmed for the part
03 · Typical Use Cases
Where Arc Segment magnets go to work
Industrial BLDC motor rotors
Stepper motor assemblies
Wind turbine permanent-magnet generators
Magnetic couplings
Large-diameter servo motors
Electric traction motors (commercial and light automotive)
04 · Dimensions & Tolerances
Drawing dimensions and tolerances
| Parameter | Specification |
|---|---|
| Typical dimensions | Chord or radii, angle, thickness and axial length specified on the drawing |
| Tolerances | Dimensional and angular limits agreed per feature after drawing review |
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 Arc Segment
N42H
120°C classN42H reference: 40–43 MGOe at 20°C, with a nominal 120°C temperature class.
Reference; drawing review required
N45H
120°C classN45H reference: 43–46 MGOe at 20°C, with a nominal 120°C temperature class.
Reference; drawing review required
N42SH
150°C classN42SH reference: 40–43 MGOe at 20°C, with a nominal 150°C temperature class.
Reference; drawing review required
N45SH
150°C classN45SH reference: 43–46 MGOe at 20°C, with a nominal 150°C temperature class.
Reference; drawing review required
N42UH
180°C classN42UH reference: 40–43 MGOe at 20°C, with a nominal 180°C temperature class.
Reference; drawing review required
06 · Related Applications
Related Applications
Industrial Automation
NdFeB magnets for stepper motors, servo drives, linear actuators, magnetic couplings, and factory automation equipment across European and North American manufacturing.
Wind Turbines
NdFeB block and tile design inputs for permanent-magnet wind generators.
EV Motors
NdFeB magnet design inputs for permanent-magnet traction motors, auxiliary drives and e-axles.
Frequently Asked Questions
When should I use arc segments instead of radial multipole rings?
+
Compare the complete motor designs. Segments allow separate pole pieces; a one-piece radial ring removes joints between magnetic segments. Tooling, assembly and inspection costs depend on geometry and quantity. Matched motor tests are needed to compare torque ripple or efficiency.
What grade is best for arc segments in wind generators?
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Use the generator temperature map, opposing fields and material curves to select a grade. An SH or UH label alone does not establish hot performance, corrosion protection or service life.
Can you review custom arc curvatures?
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Send the rotor or housing drawing with radii, arc angle, pole count, grade target and volume. Mainrich confirms the manufacturing route, tooling and inspection requirements before quoting.
Next step
Request a Quote for Arc Segment 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.