In This Article
Key Takeaways
- ◆A cobot label does not determine the motor architecture or magnet grade.
- ◆Set field and dimensional limits from the actual motor and sensing requirements.
- ◆Select the grade using the actual hot demagnetization curves, the magnetic circuit working point and the worst opposing field. A suffix is a nominal material class, not a guaranteed motor temperature limit or a chemical recipe. 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. Confirm the grade, suffix, geometry and production route for each drawing. This summary does not offer every combination; grades outside it in educational examples are not Mainrich supply offers.
- ◆Do not calculate magnet cost by multiplying an oxide benchmark by the whole magnet mass.
- ◆The reported N45H magnetic comparison and the separate historical 50H Dy-reduction example have different scopes. See the GBD evidence and limitations. Finished-part savings require a quotation and qualification of the proposed route.
Define the joint duty
Specify joint torque and speed over time, gear ratio, motor current and cooling. The magnet experiences motor-side conditions, which must be calculated from the complete actuator. Separate position-sensing requirements from torque production. A generic mass of magnets per cobot is not a design input.
Choose construction from the motor design
Compare a ring or segmented option using the stator, winding, air gap, drive and assembly. There is no supported universal torque-ripple percentage or named-platform construction in the available records. Set measured acceptance criteria for the intended motor.
Specify the material
Select the grade using the actual hot demagnetization curves, the magnetic circuit working point and the worst opposing field. A suffix is a nominal material class, not a guaranteed motor temperature limit or a chemical recipe. 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. Confirm the grade, suffix, geometry and production route for each drawing. This summary does not offer every combination; grades outside it in educational examples are not Mainrich supply offers.
The reported N45H magnetic comparison and the separate historical 50H Dy-reduction example have different scopes. See the GBD evidence and limitations. Finished-part savings require a quotation and qualification of the proposed route.
Control dimensions and measurement
The radial-ring TDS, Rev A of 31 July 2026, states OD 20 to 75 mm, ID 15 to 68 mm, wall 2 to 7 mm and height 5 to 50 mm, with ±0.05 mm standard dimensional tolerance within the qualified route. These limits are not freely combinable. Confirm the drawing, grade, pole pattern and individual features before quotation.
The separate integrated-Halbach route states ±0.02 mm on critical features, subject to feature and drawing confirmation. Define any angular and field-uniformity limits with the sensor position, fixture and sampling plan. Do not adopt a universal ±3° or 1% lot-variance claim without the process evidence.
Compare costs and scheduling
Quote the complete part and assembly scope. A raw-material benchmark describes a specified commodity, not the whole NdFeB magnet. Include composition, conversion, yield, tooling and qualification costs. Agree tooling, sample quantity, inspection and production milestones in the quotation. Export release depends on any required authorization. No standard prototype quantity or fixed delivery interval is promised here.
Confirm the supplier and exporter
Check the current certificate for the actual manufacturing entity, address and activity. Agree PPAP level and required reports for the order; a network relationship does not certify every plant or assembly. Grade suffixes and F/N/D series labels do not establish composition or export clearance. Classify the actual item and transaction with the exporter, including the parties, end use and route. See the export-control guide.
Frequently Asked Questions
Which grade should a cobot motor use?
+
Select the grade using the actual hot demagnetization curves, the magnetic circuit working point and the worst opposing field. A suffix is a nominal material class, not a guaranteed motor temperature limit or a chemical recipe. 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. Confirm the grade, suffix, geometry and production route for each drawing. This summary does not offer every combination; grades outside it in educational examples are not Mainrich supply offers.
Does a cobot require a radial ring?
+
Compare constructions against the actual motor requirements. No universal architecture is established by this guide.
How should I calculate material cost?
+
Quote the complete part and assembly scope. A raw-material benchmark describes a specified commodity, not the whole NdFeB magnet. Include composition, conversion, yield, tooling and qualification costs. Agree tooling, sample quantity, inspection and production milestones in the quotation. Export release depends on any required authorization. No standard prototype quantity or fixed delivery interval is promised here.
Does an SH or UH suffix establish licence status?
+
Grade suffixes and F/N/D series labels do not establish composition or export clearance. Classify the actual item and transaction with the exporter, including the parties, end use and route. See the export-control guide.
Can I request GBD at a fixed saving?
+
The reported N45H magnetic comparison and the separate historical 50H Dy-reduction example have different scopes. See the GBD evidence and limitations. Finished-part savings require a quotation and qualification of the proposed route.
Send the joint-motor drawing, operating duty and acceptance requirements for a supply review.
Related Reading