NdFeB Shape Selection Guide for OEM RFQ

In RFQ reviews, the same issue appears repeatedly: the price table is complete, but geometry and acceptance fields are still ambiguous.

That is why first-sample outcomes drift, even when quoted unit prices look similar. This page focuses on the fields that actually change decision quality.

Before you release RFQ, lock these decisions

1. Which shape family best fits your mechanical function.
2. Which drawing fields must be fixed before RFQ.
3. Which material and coating constraints should be declared early.
4. How to compare quotes using one scoring logic.

1) Choose shape from function, not from catalog habit

Use this as a practical first-pass filter.

2) Convert function into a complete drawing package

A drawing with only nominal dimensions is not RFQ-ready.

Use three criticality classes before release:

Minimum RFQ drawing package:

• 2D drawing with revision number and date.
• Criticality marks (A/B/C) per feature.
• Datums and measurement references for key dimensions.
• Magnetization direction diagram.
• Coating and post-coating dimensional expectation.

3) Lock material class and temperature assumptions early

Many RFQs stop at N35 or N52. That is usually not enough once thermal load becomes a real constraint.

Buyer baseline for temperature class communication (typical industry convention, final values must follow supplier data sheet):

In RFQ text, include:

• Target operating temperature range (continuous and peak).
• Demagnetization risk context (duty cycle, nearby heat source, enclosure).
• Whether thermal margin is prioritized over maximum magnetic strength.

4) Add coating and environment constraints before quote comparison

Coating should be selected by environment and handling profile, not by default supplier preference.

Declare at least:

• Environment: dry indoor / humid / corrosive / mixed transport.
• Handling mode: manual, semi-automated, automated.
• Mechanical stress points: edge contact, insertion pressure, fastener seating.

Without these fields, suppliers may quote different coating stacks under the same label, and comparison becomes misleading.

5) Pre-RFQ cost and lead-time drivers buyers should control

6) Use one supplier comparison scorecard (100 points)

If each buyer compares quotes differently, decisions become slow and political.

Recommended scoring split:

Use a shared sheet and require cross-functional sign-off (engineering + procurement + quality).

7) Copy-paste RFQ skeleton (buyer-ready)

Use this block in inquiry email or supplier portal form:

Subject: RFQ - NdFeB Magnet Program - [Project Name]

1) Drawing and revision:
2) Shape family and key dimensions:
3) Critical features (Class A/B/C):
4) Magnet grade and temperature class target:
5) Magnetization direction (with diagram reference):
6) Coating requirement and environment profile:
7) Sample quantity and sample validation deadline:
8) Pilot quantity and mass-production forecast:
9) Destination and target Incoterm:
10) Required lead-time window:
11) Required documents (inspection report / material cert / packing spec):

8) Red flags before PO release

Do not release PO if any of these remain unresolved:

• Supplier quote does not reference your exact drawing revision.
• Magnetization direction is described in text only, no diagram.
• Coating is quoted as "standard" without environment fit explanation.
• Sample acceptance criteria are not written and signed.
• Mass-production inspection logic is still "to be discussed".

9) Reference standards buyers often cite

The exact standards depend on your industry and contract terms, but these are commonly used in RFQ and release communication:

• ISO 2768 (general tolerances, when explicitly agreed).
• ISO 2859-1 (attribute sampling plans for incoming/outgoing checks).
• ASTM B117 or ISO 9227 (salt spray method reference for corrosion test planning).
• Customer-specific drawing and control-plan standards (must override generic defaults when conflict exists).

10) Worked quote-comparison example (3 suppliers, same drawing)

When teams say "Supplier A is cheaper," the statement is often incomplete. The real decision is total weighted score under one rule set.

Example scorecard (100 points):

Interpretation:

• Supplier A may show the lowest unit price, but weak sample logic and delivery confidence create higher launch risk.
• Supplier B can be commercially "more expensive per piece" but still win on total program stability.
• Supplier C is acceptable for short runs, but not ideal for strict release windows.

11) Data pack buyers should require before PO

If one of these files is missing, release risk is usually underestimated.

12) Function-to-shape decision map (quick visual)

Final note

A better RFQ package does not remove all risk, but it removes most avoidable ambiguity before money and schedule are committed. If your team already has an internal checklist, map it to the sections above and close the missing fields first.

When your RFQ file is ready, send it to our team at [email protected] or WhatsApp +8618857971991 for engineering review and manufacturability feedback. If you need companion guidance, see:

• How to Define Magnetization and Coating in Your NdFeB RFQ
• Sample-to-Mass Production Quality Gates for NdFeB OEM Programs