Hybrid page: purchase tool + decision report
Arc magnets buy checker for RFQ-ready supplier comparison
Enter the purchase fields you know. The checker returns whether your arc magnet request is a budget request, RFQ-ready, non-comparable, or needs engineering hold before price ranking.
Tool first
Result in one run
Purchase pack
12 core fields
Evidence dated
June 14, 2026
Published: June 26, 2026. Updated: June 26, 2026. Evidence accessed: June 14, 2026.
Purchase boundary
This tool prepares a comparable Purchasing package. It does not generate a binding supplier purchase, verify live stock, or replace magnetic, thermal, coating, and retention validation.
Boundary
RFQ preparation only. Supplier purchase, sample, and validation evidence are still required.
Buyer readiness inputs
Defaults represent a pilot BLDC rotor RFQ. Boundary errors are recoverable and shown before results.
Boundary: 5-400
Boundary: 1-390
Boundary: 5-180
Boundary: 2-180
Boundary: 1-1000000
Boundary: 1-12
Boundary: 3-240
Boundary: -40-320
Boundary: 0-60000
Required for comparable delivered-cost purchases; budget requests may leave it provisional.
Visual evidence
Buyer readiness starts with measurable arc magnet geometry
The Purchasing package should tie every supplier response back to the same OD, ID, arc angle, length, tolerance convention, and drawing revision. Visual measurement context makes the purchase request easier to audit than a price-only email thread.
Result feedback
Same inputs produce the same deterministic screening result. Empty state remains visible until you run the checker.
Buyer readiness score
0/100
Run the checker to classify buyer readiness and expose missing Purchasing fields.
Spec0/70
Evidence0/40
Compare0/40
Next action
Enter the known purchase fields, then run the checker before ranking supplier offers.
Applicability and uncertainty
Results are only reliable after the checker parses every required number and validates the boundary ranges.
Radial thickness
Pending
Arc length
Pending
Approx. volume
Pending
Tip speed
Pending
Missing or watch fields
- Run checker to identify missing material, drawing, magnetization, coating, certificate, supplier-count, and destination fields.
Suitable for
- Budget request
- RFQ cleanup
- Supplier screening
Not suitable for
- Purchase order release
- Safety-critical approval
- Price ranking before a checker run
Report summary
Core conclusions for arc magnet purchases
The dominant useful intent is purchase preparation and supplier comparison. The page keeps price estimation, pricelist generation, and manufacturer qualification as adjacent routes instead of duplicating them here.
12 fields
Minimum comparable purchase pack
OD, ID, arc angle, length, material, grade, coating, magnetization, quantity, lead time, operating temperature, and destination should be normalized before purchase comparison.
3+ suppliers
Comparison needs enough offers
One purchase can set a budget signal; three or more supplier responses are a more defensible baseline for commercial comparison.
0 final approvals
Purchases are not validation
A purchase can confirm commercial intent, but magnetic performance, retention, coating, and thermal behavior still need supplier evidence and sample tests.
2026-06-14
Evidence timestamp
Official reports, standards pages, supplier RFQ pages, and trade guidance were checked on June 14, 2026. Supplier prices, stock, export controls, and purchase validity are time-sensitive.
Br / HcJ / BHmax
Grade labels need properties
Purchase lines that say only N42, N48SH, or SmCo grade are incomplete unless measured properties and a test method are attached.
EU / US
Destination affects evidence
Regulated products may need origin, composition, recyclability, recycled-content, DFARS/customer flow-down, or import documentation before purchase.
Suitable
Budget screening, supplier RFQs, and sample purchase preparation when assumptions are explicit and missing fields are tracked.
Not suitable
Purchase-order release, safety-critical approval, or purchase ranking when magnetization, grade evidence, drawing revision, and destination requirements are still missing.
Main risk
The biggest commercial mistake is comparing offers that are not technically equivalent. Normalize the RFQ pack before ranking price.
Methodology
How the checker turns purchase fields into a decision
The scoring is deterministic. It rewards drawing control, material clarity, magnetization, coating, supplier count, evidence maturity, and destination clarity, then penalizes high heat, high speed, compressed schedule, or material uncertainty.
| Step | Inputs | Output | Boundary |
|---|---|---|---|
| Specification completeness | Geometry, material, coating, magnetization, destination | Spec completeness score and missing-field list | The tool does not verify drawing tolerances or supplier interpretation of arc/chord definitions. |
| Purchasing readiness | Purchase goal, buyer stage, suppliers to compare, evidence level | Buyer readiness and comparability status | It cannot pull live supplier stock, currency, freight, tariff, or tooling offers. |
| Application risk screen | Temperature, RPM, material family, set quantity, lead time | Engineering-hold flags for heat, speed, schedule, and material uncertainty | Final release still needs magnetic, thermal, mechanical, coating, and assembly validation. |
| Purchasing package output | All user fields plus checker result | Purchase pack, next action, supplier inquiry body | Supplier commercial terms and technical acceptance criteria must still be negotiated. |
Purchase pack
Minimum package for comparable arc magnet purchases
A purchase pack should let suppliers respond to the same technical, evidence, and commercial baseline. Unknown values are allowed for early budgets, but they must be labeled as assumptions.
| Module | Include | Why it matters |
|---|---|---|
| Geometry package | OD, ID, arc angle, length, segment count, tolerances, drawing revision, and datum convention | Prevents suppliers from quoting incompatible radius, chord, or arc definitions. |
| Magnetic package | Material, grade, Br, HcB, HcJ, BHmax, test method, magnetization diagram, and operating temperature | Makes grade claims comparable and ties performance to application limits. |
| Surface and assembly package | Coating, corrosion target, adhesive/retention method, handling notes, inspection points | Controls coating failure, adhesive mismatch, and mechanical retention risk. |
| Commercial package | Sample, pilot, production quantities, target lead time, Incoterms 2020 rule, named place, destination, currency, and purchase validity | Separates prototype price from production economics and logistics assumptions. |
| Logistics and customs package | Packaging, export paperwork, insurance basis, customs party, HS code assumption, freight exclusion/inclusion, and magnet shipping notes | Prevents a low part price from hiding shipment, documentation, or import-risk differences. |
| Compliance package | Origin, composition, RoHS/REACH, customer flow-downs, recycled-content/recyclability fields where relevant | Avoids treating compliance evidence as a post-order paperwork task. |
| Validation package | Sample plan, dimensional inspection, magnetic test method, certificate linkage, coating checks, retention review, and exception log | Keeps a purchase from being mistaken for production or motor-performance approval. |
Current checker RFQ pack
Generated from your latest input state.
- Run the checker to generate a normalized purchase pack from your inputs.
Known unknowns disclosure
These items are deliberately not guessed by the tool.
The checker does not estimate live supplier price, real-time stock, tooling cost, exchange rate, freight, tariff, yield, or sample performance.
Treat incomplete supplier responses as open questions, not as equivalent cheaper offers.
Sources and evidence
Source-backed purchase assumptions
Public sources support the structure of the purchase pack, but final acceptance values must come from your drawing, purchased standards where applicable, supplier certificates, and sample validation.
| ID | Source | Signal | Use on this page | Date |
|---|---|---|---|---|
| S1 | ASTM A1101-23 NdFeB magnet specification page | ASTM lists sintered and fully dense NdFeB permanent magnets as commercially available across wide compositions and magnetic properties, with Br and HcJ ranges shown in the public abstract. | Turns a purchasing line from a grade label into a request for magnetic properties, certificate linkage, and material acceptance evidence. | Accessed June 14, 2026 |
| S2 | IEC 60404-5:2015 permanent magnet measurement listing | IEC 60404-5:2015 defines measurement methods for flux density, magnetic polarization, field strength, demagnetization curve, and recoil line of permanent magnet materials. | Supports asking suppliers to identify the test method behind Br, HcJ, BHmax, and certificate claims. | Accessed June 14, 2026 |
| S3 | USGS Mineral Commodity Summaries 2026: Rare Earths | USGS reports 2025 U.S. rare-earth mine output at 51,000 metric tons REO in mineral concentrates; rare-earth compounds/metals imports rose 169% in 2025, and magnets were the leading global end use. | Adds date-bound supply-risk context; it does not convert directly into a per-piece arc magnet purchase. | 2026 report, accessed June 14, 2026 |
| S4 | USGS Mineral Commodity Summaries 2026: Heavy Rare Earths & Trade Updates | USGS identifies terbium and dysprosium among heavy rare earths used in high-strength magnets; public mineral summaries support treating Dy/Tb exposure as a dated supply-risk input rather than a live lead-time forecast. | Supports purchase-validity, Dy/Tb exposure, allocation, and fallback-grade questions for high-HcJ or high-temperature magnets while leaving exact licensing impact to supplier confirmation. | 2026 report, accessed June 2026 |
| S5 | European Commission Critical Raw Materials Act page | The Commission describes 2030 strategic raw-material benchmarks and permanent-magnet circularity topics, including labelling, recycled-content, and recyclability requirements that phase in by product and date. | Turns EU-bound purchase requests into early origin, composition, recyclability, recycled-content, and safe-removal questions. | Accessed June 2026 |
| S6 | European Court of Auditors Special Report 04/2026 | ECA treats rare-earth elements for permanent magnets as a strategic raw material grouping and reports EU dependence above 65% on China for processed rare-earth elements relevant to permanent magnets. | Explains why EU purchase packs should ask for origin, supply-risk exceptions, and substitution notes without pretending public data can predict supplier capacity. | 2026 report, accessed June 14, 2026 |
| S7 | U.S. International Trade Administration Incoterms guidance | The ITA explains that Incoterms define seller and buyer responsibilities for shipment, insurance, documentation, customs clearance, tasks, costs, and risk. | Supports requiring an Incoterms 2020 rule and named place before comparing delivered purchasing lines. | Accessed June 14, 2026 |
| S8 | eCFR 16 CFR Part 1262 Safety Standard for Magnets | The U.S. rule covers certain consumer products with loose or separable magnets and excludes products sold solely to professional, commercial, or industrial users; covered small magnets must have flux index below 50 kG2 mm2. | Prevents overapplying consumer magnet rules to industrial motor arcs while flagging U.S. consumer-adjacent purchase cases. | Accessed June 14, 2026 |
| S9 | Stanford Magnets neodymium arc magnets page | The supplier page presents arc magnets for motors/generators, states that specific sizes can be requested for a custom purchase, and lists size, grade, coating, orientation, and drawing upload signals. | Supports the practical RFQ pack fields while keeping supplier claims separate from standards and macro supply evidence. | Accessed June 14, 2026 |
| S10 | K&J Magnetics custom neodymium magnets page | The supplier states custom magnet purchases can cover many shapes, sizes, and grades, with custom order minimum purchase and multi-week fulfillment notes. | Provides a public counterexample to instant stock pricing: custom purchases may include MOQ, lead time, and non-recurring assumptions. | Accessed June 14, 2026 |
Evidence translation table
Public claims become RFQ questions, not automatic acceptance.
| Claim | Evidence needed | Public support | Limitation |
|---|---|---|---|
| Custom arc magnet purchase | Drawing revision, geometry convention, grade, coating, magnetization diagram, and quantity tiers | Supplier pages commonly invite custom purchases and exact specification submission. | Public pages do not prove the supplier can meet your exact tolerance, yield, or lead time. |
| N-grade or high-temperature NdFeB | Br, HcB, HcJ, BHmax, test method, test temperature, and certificate sample geometry | ASTM and IEC listings show why magnetic property and measurement-method details matter beyond grade names. | A batch certificate is not final assembled motor validation. |
| Fast purchase for production quantity | Tooling status, fixture plan, process route, yield assumptions, purchase validity, and shipment terms | Custom arc magnet pages indicate purchase-first workflows; production repeatability still needs process evidence. | Live capacity, freight, tariff, and supplier allocation cannot be inferred from public snippets. |
| EU-ready or traceable magnet | Origin, composition, recyclability, recycled-content statement, safe-removal data, and customer flow-down mapping | EU Critical Raw Materials Act direction makes magnet circularity and traceability commercially relevant. | Exact obligations depend on product category, date, importer role, and customer contract. |
Source-to-RFQ question map
Stage1b additions convert each source into a buyer action instead of a passive citation.
| Source family | RFQ question to ask | Decision use |
|---|---|---|
| ASTM / IEC | Which measured Br, HcB, HcJ, BHmax, temperature, and test method will appear on the certificate? | Reject purchasing lines that use only a grade label when the goal is pilot, production, or high-temperature comparison. |
| USGS rare earths | Does the purchased grade depend on Dy/Tb or another constrained heavy rare earth, and how long is price/material allocation valid? | Ask for fallback grades before locking a high-HcJ NdFeB or SmCo purchase into a schedule. |
| EU CRM Act / ECA | For EU-bound programs, can the supplier state origin, composition, recyclability, recycled-content status, and safe-removal assumptions where in scope? | Keep unknown fields marked as pending; do not claim EU readiness from a generic supplier purchase. |
| ITA Incoterms | What Incoterms 2020 rule, named place, insurance basis, documentation responsibility, and customs party does the price assume? | Normalize freight and import risk before ranking delivered or landed purchase totals. |
| 16 CFR Part 1262 | Is the magnet sold solely for industrial/professional use, or could it become a U.S. consumer product with loose or separable magnets? | Document the commercial-use boundary or request flux-index/product-safety review before consumer-channel quoting. |
| Supplier RFQ pages | Are MOQ, tooling, magnetization fixture, sample lead time, production lead time, and exception notes separated? | Avoid comparing stock, prototype, and custom tooling economics as if they were the same offer. |
Public evidence limits
These conclusions remain 待确认/暂无可靠公开数据 and must be closed by supplier response or validation.
| Unconfirmed item | Why public evidence is insufficient | Minimum action |
|---|---|---|
| Live unit price | Public rare-earth and supplier pages do not map a generic arc geometry to tooling, yield, freight, tariff, and margin. | Use the checker for RFQ completeness, then request supplier price rows. |
| Supplier process capability | A public product page cannot prove tolerance capability, magnetization fixture readiness, coating yield, or repeatability for your drawing. | Ask for sample plan, inspection method, exception notes, and process evidence. |
| Final motor performance | Standards pages and certificates describe material evidence, not assembled air-gap flux, retention, heat soak, or torque validation. | Treat purchases as sourcing inputs and run sample-level validation before PO release. |
| Regulatory applicability | EU raw-material obligations and U.S. consumer magnet rules depend on product category, role, destination, and date. | Mark compliance fields pending until the importer, customer flow-downs, and sales channel are known. |
Comparison and risk
Choose the right purchase path before ranking price
Purchase requests can look similar while carrying very different technical and commercial risk. The table separates budget, comparable RFQ, PO-ready, and engineering-hold routes.
| Route | Best for | Required evidence | Risk | Action |
|---|---|---|---|---|
| Budget purchase request | Early concept, investor estimate, supplier discovery | Basic geometry and target material assumptions | Wide purchase spread; suppliers may purchase different assumptions | Ask for ranges and list every assumption as provisional. |
| Comparable RFQ | Sample or pilot sourcing with at least three suppliers | Drawing, material/grade, coating, magnetization, quantity tiers | Missing certificate/test method can hide performance differences | Normalize fields and reject purchasing lines with unclosed assumptions. |
| PO-ready purchase | Production program after sample and evidence review | Controlled drawing, certificate, inspection plan, delivery, packaging, compliance evidence | Purchase may still fail if process capability or validation is incomplete | Freeze acceptance criteria and sample validation before purchase order. |
| Engineering hold | High heat, high RPM, unknown material, safety-critical use | Design assumptions, magnetic/thermal/mechanical review | Fast purchase can encourage a poor material or geometry lock | Resolve engineering constraints before commercial comparison. |
| Risk | Trigger | Impact | Mitigation |
|---|---|---|---|
| Non-comparable purchases | Suppliers purchase different grades, tolerances, coatings, or Incoterms. | The lowest line item may be the least complete offer. | Use one RFQ pack and require exception notes for every supplier deviation. |
| Magnetization ambiguity | The purchase says arc magnet but omits radial, diametrical, or circumferential direction. | A physically fitting part may fail torque, sensor, or assembly requirements. | Attach a magnetization diagram and require supplier confirmation before samples. |
| Thermal demagnetization | High operating temperature with only an N-grade label and no HcJ evidence. | Samples can lose margin under peak duty even if room-temperature flux looks acceptable. | Ask for HcJ, irreversible loss data where available, and grade fallback options. |
| Tooling and fixture surprise | Custom arc, new magnetization fixture, or tight tolerance is not separated in the purchase. | Unit price, lead time, and repeatability change after purchase acceptance. | Split tooling, fixture, sample, and production rows in the supplier response template. |
| Compliance gap | Destination market, origin, chemical composition, or customer flow-down is absent. | A technically acceptable magnet can be rejected by the buyer or importer. | Name destination and compliance evidence in the first purchase request. |
| Rare-earth supply exposure & Export Controls | High-temperature NdFeB, Dy/Tb exposure, or SmCo is purchased without validity, allocation, and end-use disclosure notes. | Price, material allocation, and lead time can change before sample or production release, especially when heavy rare-earth content is unresolved. | Ask for purchase validity, substitution plan, heavy rare-earth exposure, and supplier-confirmed export-control or end-user disclosure requirements where relevant. |
Scenario examples
Four purchase outcomes from similar arc magnet requests
Early budget purchase
60 mm OD, unknown material, no drawing, 24 sets, one supplier, room-temperature concept
Budget request
Ask for a range and supplier assumptions, then create a controlled drawing before comparison.
Pilot BLDC RFQ
92 mm OD, 78 mm ID, 30 deg arc, 1200 sets, 135 C, drawing sketch, 3 suppliers
RFQ-ready after magnetization closure
Attach magnetization diagram and require certificate/test-method fields before price ranking.
High-speed production purchase
132 mm OD, 115 mm ID, 18 deg arc, 48000 sets, 12000 RPM, 180 C, EU destination
Engineering hold
Resolve HcJ, rare-earth exposure, retention, thermal margin, and compliance evidence before PO quoting.
Replacement supplier comparison
Measured old segment, controlled drawing, known coating, unknown grade, 600 sets, 4 suppliers
Purchase not comparable until grade evidence closes
Ask suppliers to purchase against measured Br/HcJ/BHmax target or test a reference sample.
Anonymized RFQ cleanup example
Representative 2026 pilot buyer pack; commercial identities, prices, and drawing numbers removed.
Before cleanup
- 92 mm OD arc segment, quantity 1200 sets.
- Grade listed as N48SH, but no Br/HcJ/BHmax target.
- No magnetization diagram or named Incoterms place.
- Supplier A quoted stock-like terms; Supplier B included tooling.
After checker cleanup
- Drawing revision, OD/ID/angle/length, and tolerance convention locked.
- Certificate request added for Br, HcJ, BHmax, test method, and test temperature.
- Radial magnetization sketch, coating stack, and sample inspection plan attached.
- EXW/FCA named place separated from tooling, sample, and production rows.
FAQ
Arc magnet purchase questions by decision type
Internal paths
Use adjacent pages when the purchase question narrows
This route owns RFQ readiness and purchasing readiness. Use these pages for price bands, tiered pricelists, online buying, manufacturer qualification, and material-specific decisions.
Send a purchase-ready arc magnet inquiry
Include checker outputs, drawing fields, magnetization direction, material, coating, quantity tiers, lead time, destination, and certificate requirements.
Use the result as the email brief
The generated email body carries the current inputs and missing-field list so the discussion starts from the same purchase assumptions.
Budget request
RFQ cleanup
Supplier screening