# Why is a bearing base number insufficient for a sourcing brief?

Record the full maker designation rather than only the base number. Keep the dimensional family, seals or shields, internal clearance and other specified features attached to that designation. Supplementary codes can be manufacturer-specific, so similar suffixes are not proof of interchangeability. Ask for the relevant maker documentation and approval of any substitute. A listing or marked box alone does not establish authenticity, stock or suitability for an application.

Materially updated: 2026-10-16

## When to use this checklist

Use this when a bearing number or photograph is too incomplete to establish the required variant. Record the full designation and maker-specific suffixes together with dimensions, closure, clearance and permitted substitution.

Editorial decision aid: this does not obtain quotations, contact suppliers or approve product conformity.

## Minimum buyer brief

Full reference; maker/code edition; dimensions; closure; clearance; allowed substitution; quantity/unit.

| Field | Buyer input | Evidence check | Reject or unknown |
|---|---|---|---|
| full manufacturer designation | Retain the entire maker part designation as supplied. | Check basic and supplementary portions in that maker documentation. | Do not truncate suffixes to force a match. |
| bearing type and dimensions | Record the required type and dimensional reference. | Keep boundary dimensions linked to the stated designation. | Same base digits alone do not establish all required features. |
| seal/shield suffix | Use the maker-specific meaning for the actual suffix. | Keep documentation source and edition. | Never mapZZ/2RS across makers without support. |
| clearance | Retain the stated clearance designation or UNKNOWN. | Check whether the buyer requires a particular class. | Do not silently choose a different class. |
| tolerance class | Record the buyer-stated precision/tolerance requirement. | Require relevant product documentation for a claimed match. | An omitted class cannot be upgraded to the requested class. |
| lubrication/application requirement | Record explicit buyer service requirements and who approves fit. | Request documentation or engineering review where needed. | No life, authenticity or interchangeability guarantee from a listing. |

## Exclude or resolve

Reject stripped suffixes as equivalent; hold cross-brand code translations without documentation; no authenticity or service-life guarantee.

## Questions to copy into a supplier enquiry

What does each suffix mean in this maker documentation? Which features differ? Who can approve the substitute for the intended application?

## Evidence and price basis

BUYER_STATED is explicit buyer input; SOURCE_OBSERVED is a dated source; DERIVED is labeled interpretation. OBSERVED does not mean SUPPLIER_CONFIRMED. Missing facts remain UNKNOWN; TO_CONFIRM describes the next question. Preserve currency, unit, quantity tier, SKU and date; a listing is not a supplier-confirmed quote. Never infer stock, MOQ waivers or certification.

## References and limits

- [NSK bearing designation guide](https://www.nsk.com/tools-resources/abc-bearings/bearing-designations/): Basic/supplementary designation and maker-specific code scope; no cross-brand equivalence, guaranteed life or stock.
- [Current free discovery and v4 public resource](https://api.seekapi.ai/mcp): Runtime mode admission and same public sample only; no new purchase or supplier facts.

## Continue

[Parent sourcing library](/sourcing) · [Related category](/sourcing/find-china-suppliers) · [Human: review a free image brief](/china-supply-check#image-supply-check) · [Agent: free discovery and preparation](/for-agents#china-supply-check-mcp) · [Runnable free SDK examples](/for-agents#free-quickstart) · [Public sample](/china-supply-check/sample)

Preparation does not purchase or contact suppliers. Image Stripe USD 2.99 and text/model x402 2.99 USDC are separate paid routes; image x402 and text/model Stripe are OFF in the dated observation. Check live admission. The proposed $19.90 RFQ service is not open for purchase.