Arc Magnets for Sale: Sourcing Checker
Comparing arc magnets for sale for a motor or prototype? Choose a material and quantity to prepare a sourcing checklist and RFQ brief. This is an inquiry guide; price, stock and delivery require supplier confirmation.
Published · Reviewed · By EVMotorMagnets
Four decisions before buying arc magnets
Stock, machined blank or custom order?
Use the same drawing revision to compare all three routes. These are procurement questions, not a claim that any listed route is currently available.
| Route | When to investigate | Main uncertainty | Next action |
|---|---|---|---|
| Catalog arc | A listed part appears to match | Exact pole map, grade and available quantity | Obtain the drawing and a sample; verify stock in writing |
| Machined blank | A specialist can make the required geometry | Blank size, orientation, yield and finishing | Request feasibility and a separate setup charge |
| Custom manufacture | No existing part or blank satisfies the design | Tooling, minimum order and process qualification | Approve samples and written acceptance criteria first |
Fabrication basis: Arnold Magnetic Technologies: precision magnetic assemblies. The route selection and quote comparison are editorial procurement guidance.
Ready to compare a stock part or a custom quote?
For a stock neodymium arc, inspect the supplier drawing and pole direction in the K&J arc segment catalog. This independent catalog is an example, not an endorsement or confirmation of availability. For a custom requirement, include your drawing and request a written quote.
Request an arc magnet quoteMaterial comparison and manufacturing limits
| Material | Route to discuss | Constraint | Confirmation needed |
|---|---|---|---|
| Sintered NdFeB | Catalog part or supplier-machined blank | Corrosion protection and temperature-dependent grade choice | Coating, operating point and magnetic direction |
| SmCo | Specialist fabrication from a suitable blank | Brittleness and careful handling | Grade, chipping limits and sample inspection |
| Hard ferrite | Existing arc/die or diamond-ground blank; custom press if needed | Non-conductive: conventional EDM is unsuitable | Geometry feasibility, orientation and any new tooling |
Sources: Adams Magnetic Products: NdFeB and SmCo, pp. 7–8 and 18; Adams Magnetic Products: materials catalog, p. 24. No universal tolerance, tooling fee or delivery range is established by these references. Bonded and injection-molded grades need a separate process review and are outside this checker.
How the checker works — and where it stops
- Material constraint. Retrieve the relevant fabrication and handling questions.
- Batch action. Assign prototype (1–100), pilot (101–5,000) or production (5,001+).
- Inquiry readiness. An incomplete drawing gives a feasibility request; a defined drawing gives a quote-review request.
The quantity bands are editorial workflow rules, not supplier MOQs or measured economic break-even points. Identical inputs return identical checklists. The tool accepts up to 1,000,000 pieces; larger orders can use the contact route.
It has no inventory, price or supplier-capacity feed and performs no electromagnetic or mechanical simulation. Operating temperature, magnet dimensions, destination and acceptance tests remain unvalidated. Results do not authorize production or a material substitution.
View a checked example: Ferrite, 5,001 pieces
Drawing and RFQ checklist
- OR and IR (or explicitly labeled OD and ID), arc angle and axial length, with units.
- Grade, magnetic orientation and north/south pole map.
- Finished-part tolerances, coating, edge treatment and inspection datums.
- Application, temperature range, assembly method and required verification.
- Sample and production quantities, destination and required delivery date.
State whether dimensions apply before or after coating. Request separate prices for parts, setup/tooling, inspection and freight, plus quote validity and tooling ownership. A missing value should be marked “to confirm,” not guessed.
Misuse, cost and fit risks
| Risk | Why it matters | Mitigation / alternative |
|---|---|---|
| Pole-map mismatch | Shape alone cannot establish the required magnetization | Approve a pole map and test the assembly; investigate a custom orientation if stock does not match |
| Unexpected setup cost | A low part price can omit tooling, samples and inspection | Compare total cost at the same quantity; ask about existing blanks and dies |
| Assembly fit | Radius, adhesive, coating, hub and runout affect clearance together | Review the full tolerance stack and finished-part drawing; inspect a sample assembly |
| Material substitution | A change in grade or material can alter thermal and magnetic behavior | Have the designer review the circuit and operating conditions before substitution |
Magnetization basis: K&J Magnetics: magnetization directions. A parallel-magnetized arc is not automatically unsuitable for a motor. No universal torque loss, air-gap error or coating thickness is inferred here; the mitigations are engineering review steps.
Three example procurement decisions
Illustrative scenarios, not customer case studies or supplier quotes.
Buying and specification questions
Can I buy these magnets directly on this page?
This is a sourcing checker and inquiry route. There is no live stock feed or checkout. Ask for a written quote confirming specification, availability, minimum order, shipping and payment terms.
Does a prototype always avoid a new die?
No. Existing stock, blank dimensions, orientation and inspection needs determine the route. Ask the supplier to separate setup and tooling from part costs.
Does ferrite always require a new mold?
No. Existing dies or suitable blanks may be available. Diamond grinding is possible, but geometry and economics need supplier review; conventional wire-EDM is unsuitable for non-conductive ferrite.
Are parallel-magnetized arcs automatically wrong for a motor?
No. Arc segments with parallel magnetization can approximate a radial ring. Specify the pole map and validate the assembled design; this checker cannot predict torque or efficiency.
How do I compare two quotes fairly?
Use the same drawing revision, grade, pole map, finished-part tolerances, coating and acceptance tests. Compare total sample and production costs, including setup, inspection and shipping.
Can the checker confirm temperature rating or air gap?
No. It does not model a magnetic circuit, thermal conditions, rotor speed or an assembly tolerance stack. Supply those requirements for engineering review.
What if I have no drawing yet?
Choose the incomplete drawing option and send a feasibility inquiry with an application sketch, available space and quantity. Resolve missing dimensions and magnetization before ordering production parts.
Can I cut or grind a magnet myself?
Use a specialist fabricator. Brittle parts, coatings and magnetic properties need a controlled process. Request finished, inspected samples instead of assuming a stock part can be reworked.
Are the quantity bands supplier minimum orders?
No. The bands only organize procurement advice: 1–100 prototype, 101–5,000 pilot, and 5,001–1,000,000 production pieces. The input cap is a tool limit. Suppliers set their own minimum orders and capacity.
Sources, dates and evidence limits
Published by EVMotorMagnets; company and contact details are available on our about page. Technical sources reviewed . These manufacturer references support the stated material/process facts. They do not verify EVMotorMagnets inventory, commercial offers or manufacturing capability.
- K&J Magnetics: magnetization directions
Arc pole faces and parallel versus true radial magnetization; no motor performance guarantee.
- Adams Magnetic Products: materials catalog, p. 24
Ferrite diamond grinding and electrical non-conductivity; no custom tooling price.
- Arnold Magnetic Technologies: precision magnetic assemblies
Prototype-to-production fabrication capabilities, including slicing, grinding and EDM; feasibility requires a drawing.
- Adams Magnetic Products: NdFeB and SmCo, pp. 7–8 and 18
Grade-dependent temperature behavior, NdFeB coatings and SmCo brittleness; see printed pp. 7–8 and 18 (PDF pages 8–9 and 19). No current pricing or inventory.
Cost, tooling fees, achievable tolerances and delivery dates remain unknown without a supplier-specific quote. Quantity bands, sourcing paths and RFQ recommendations are editorial rules, not statistics from these sources.
Prepare a reviewable inquiry
Run the checker, copy the brief and attach your drawing. Ask for a sample plan and a written breakdown before committing to an order.