Replacement bearing RFQ: preserve the full designation

A replacement-bearing quote needs the full manufacturer designation and application record. Matching three dimensions is a filter, not approval; a changed seal, clearance or other suffix requirement needs a documented comparison.

Let incomplete identification take a different quote route

A buyer with a complete approved designation and a buyer holding only damaged markings should not receive the same unconditional quote. Keep the uncertainty visible so a fast price does not turn a guessed variant into the purchase specification.

Write unconfirmed in the required field when necessary and keep proposed identities in a separate column. A supplier may quote candidate availability while identification continues, but that preliminary price should not be described as an approved replacement. Do not use a catalogue speed or load value to fill an unknown machine duty.

Ask who supplied the identity claim and which offered goods it describes. A legitimate manufacturer document and a legitimate source for the actual goods are separate evidence questions. This route supports qualified sourcing inquiries without presenting the buying service as an authorized distributor or bearing-selection authority.

A match on bore, outside diameter and width is a good first filter, but it is not a complete specification. This tutorial helps you compile an identification package that a supplier can quote against. It does not choose a bearing arrangement or provide installation instructions.

Capture the old record before searching listings

Use the machine parts list, original purchase documentation or released maintenance specification, where available. Write down the OEM part reference, machine model and serial number, and the precise location of the bearing. The same machine may contain several bearings with different duties.

Take pictures of readable markings on the rings and, if retained, the original package. Write down the designation exactly as shown, preserving slashes, hyphens and suffixes. Clearly flag uncertain characters so the seller does not silently guess. Photograph the assembly location without dismantling equipment outside the site’s approved maintenance procedure.

Differentiate between what you know and what you measured or deduced. A damaged bearing may have unreadable markings, and an earlier replacement may already differ from the original specification. Clearly indicate to your supplier the source for each field.

Read suffixes within the manufacturer’s own system

Use the named manufacturer’s documentation for that bearing family. NSK’s motor-bearing catalogue separates series and bore information from seals or shields, internal clearance and grease information. For its listed nomenclature, C3 denotes clearance greater than CN; it is not a universal “better bearing” grade. NSK Industrial Motor Bearings.

The current catalogue keeps the basic designation separate from seal/shield, radial-clearance and grease fields. Use the applicable manufacturer record for the actual proposed bearing rather than treating a general series example as the machine requirement.

This example is not a recommendation for your machine. Do not apply one brand’s suffix meaning to another without checking that brand’s own catalogue. Do not infer suitability from a dimension match alone.

Prepare an identification table

Submit one table with the following fields:

• Required manufacturer and full designation, or “unconfirmed” where evidence is missing.
• OEM reference and source document, including revision where available.
• Machine model, serial number and bearing position.
• Bore, outside diameter and width, with units and the source of each value.
• Specified seals/shields, clearance, precision class, cage and lubrication details where documented.
• Known operating speed, loads, temperature and environment, identifying estimates as estimates.
• Quantity, destination, required date and acceptable evidence for product identity.

Do not back-fill missing application values with generic catalogue limits. Ask the responsible engineer or equipment maker to resolve important gaps. Request photos of the actual goods on offer and their packaging, tied to the designation in the quote, rather than a generic stock photo shared by multiple variants.

Put substitutions in a separate comparison

Ask the seller to present the required item and proposed item side by side. Compare full designations, documented dimensions, sealing, clearance, tolerances, lubrication and other properties relevant to the application. Require a source for each comparison, and specify who can approve the change.

An answer saying “same size, equivalent quality” does not resolve a changed seal or clearance specification. Conversely, a differently written suffix may be a genuine catalogue convention; it still needs a manufacturer-supported comparison. If the machine maker specifies a matched set or a proprietary assembly, raise that requirement before accepting an individual catalogue bearing.

Link price and timing to the approved item. A quick quote for an alternative whose technical suitability is still unresolved is not yet a usable recovery plan.

Check product identity and sourcing evidence separately

Ask for the selling entity, supply channel, invoice description, product markings and available manufacturer traceability. A catalogue PDF documents a product design, but it does not prove that the goods on offer are that product or that the seller is authorized.

For SKF-branded products, SKF recommends authorized distribution and offers manufacturer review of suspect goods using photographs and purchase evidence. Follow the named brand’s current process when authenticity is uncertain. Attractive packaging or a buyer’s visual comparison is insufficient evidence by itself. SKF brand protection guidance.

This article does not assert that 1688SpareParts or any specific seller is an authorized distributor.

Copy this bearing RFQ

“Please quote the full manufacturer designation in the attached identification table. Confirm seals/shields, internal clearance and any other documented suffix requirements. Supply the product reference, photographs of the offered item and package, supply-channel information and available identity records. List any proposed substitute separately with a field-by-field technical comparison and supporting manufacturer documents. Do not remove suffixes or substitute the product without written approval. Quote quantity, packing, destination delivery scope and lead-time assumptions.”

On receipt, reconcile the order line, package and product markings under your agreed incoming procedure. Quarantine unresolved mismatches for review before release to installation. Use the supplier-check guide for the broader sourcing assessment, then submit your identification pack through the spare-parts quote page.

AI-assisted editorial update, 26 October 2026. Sources and bilingual wording were checked with AI assistance; technical acceptance remains with the responsible provider.

Related purchasing decisions: Machinery-spare sourcing scope.