Bearing cross reference: what full, partial and verify matches really mean

Updated 2026-10-04

Why a cross-reference table cannot be a single green tick

A bearing is interchangeable on at least four different levels, and a failure at any one of them makes the swap unsafe:

1. Envelope — bore d, outside diameter D, width B and chamfer limits must fit the shaft, housing and adjacent spacers.
2. Internal clearance — C2, CN, C3 or C4 must survive the interference fits and the operating temperature (see clearance guide).
3. Closure and lubrication — open, shielded or sealed; regreaseable or greased for life (see 6205 vs 6205-2RS).
4. Performance — dynamic/static load ratings, limiting speed, precision class and cage design must cover the actual duty.

The full / partial / verify levels on MPN Base describe how far the catalogue evidence gets you down that list. They are engineering triage, not a warranty.

How each level is assigned

Full match — same envelope, same closure intent, same clearance class

A full link means both catalogue rows resolve to the same d×D×B envelope, the same closure arrangement (two contact seals, two shields, open, etc.) and the same clearance class, with load ratings inside the normal same-envelope catalogue spread.

The sealed 25×52×15 deep-groove is the textbook example:

All four fit the same shaft and housing, carry the same ISO 15 boundary dimensions and are sealed for the same kind of duty. That is what earns full.

Partial match — same envelope, different execution

A partial link shares the envelope but differs in closure, a declared suffix, or one parameter that has to be weighed. In the 6205 group, 6205 (open), 6205-ZZ (shields) and the sealed variants are all partial neighbours of one another.

Whether partial is usable is an engineering question:

• Replacing 2RS with ZZ or open in a clean, regreaseable position: often fine, and the non-contact variants run cooler and faster. You take over lubrication and contamination duty yourself.
• Replacing open/ZZ with 2RS: check the speed budget — contact-seal drag lowers the limiting speed and raises temperature — and accept that the bearing is now sealed-for-life with no regreasing path.
• Clearance mismatch (CN vs C3): a tight fit on a hot shaft consumes clearance; a C3 row is safer there, while C3 in a loose, cool idler can run noisy with more slack.

Verify — the data will not settle it

A verify link fires when ratings diverge beyond the same-envelope spread, when an inch-series and metric designation superficially collide, when a matched pair is compared with a single bearing, or when a source is missing. Open both catalogue rows, compare the numbers and measure the physical bearing before committing. Tapered-roller cone-and-cup sets are the classic trap: a cone number alone never identifies the complete assembly.

When even a “full” match is not interchangeable

Full matches the envelope and closure class. It says nothing about these, so check them on critical positions:

• Precision class — a P4/P5 spindle bearing swapped for an ordinary P0 row of the same size will lose runout and speed; the designation may look identical apart from the class suffix.
• Preload / arrangement — universal-ground angular-contact pairs (DB/DT) are not equivalent to a single bearing; see angular-contact pair guide.
• Cage and internal geometry — brands optimise differently; rating life at your load and lubricant conditions can vary even when C values look alike.
• Snap-ring groove and filling slots — one row may have an N/NR groove the other lacks, or a different ball complement.
• Lubricant fill — sealed-for-life bearings arrive with a factory grease chosen for a temperature range; food-grade, high-temperature or low-noise fills are specific designations, not commodities.
• Speed rating basis — compare like with like (reference speed vs limiting speed; grease vs oil lubrication).

Practical verification checklist

Before fitting a cross-referenced bearing into anything load- or speed-critical:

1. Measure the actual bore, OD and width with a micrometre; do not trust box labels.
2. Read the complete suffix end to end — seals/shields, clearance, precision class, snap ring, tapered bore.
3. Compare d×D×B against the envelope page for that size; every same-envelope execution is listed there.
4. Re-rate the duty: dynamic load C vs the application’s equivalent load, and limiting speed vs the actual speed, including the seal drag penalty.
5. Match the lubrication strategy: regreaseable seats need open/shielded bearings; sealed rows cannot be topped up.
6. For verify links and matched sets, open both manufacturer catalogues and record the decision — or specify the original part number.

A rule of thumb

If the position is a general-purpose motor or conveyor bearing, a full match from a reputable brand is a routine swap after a suffix check. If the position is a spindle, a preloaded pair, a high-speed or high-temperature position, or anything safety-related, treat the cross-reference as a shortlist of candidates and re-engineer from the catalogue data — the way the verify level tells you to.

Use the cross-reference tool to start from a designation and follow each graded link back to the sourced specification page.