Find the bearing part number for a given shaft bore
Enter shaft bore, outside-diameter limit, width limit, and bearing type to get source-backed ISO metric basic designations from the audited bearing tables.
A measured shaft bore gives you a bore code. The bore code plus a dimension series gives you a family of bearing numbers that fit the same shaft but occupy different amounts of room and carry different loads.
This bearing dimensions lookup covers ISO metric radial designations from the audited bearing tables. It returns the basic designation only and uses a curated set of common sizes rather than the complete ISO 15 catalog. Enter bore first, then use outside diameter, width, and bearing type to narrow the list. Every displayed number exists verbatim in the source table and decodes back to the requested bore.
Already have a number? Decode it. Suffixes, clearance and cross-vendor equivalents live there.
Bearing Decoder →Turn the dynamic load rating C and your application load P into L10 hours.
Bearing Life Calculator →Check the running speed against the ndm limit for the bore and OD you picked.
Bearing Speed Limit Checker →How It Works
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Measure the shaft bore
Measure the shaft at the bearing seat in millimetres. Bore is matched exactly. The finder does not round or substitute a nearby shaft size.
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Enter the housing envelope
Enter the maximum outside diameter and maximum width that fit the housing. Turn on exact match only when both dimensions came from an existing bearing.
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Choose the bearing type
Filter by bearing type when load direction and misalignment duty are known. Leaving the type open shows all tabulated geometries at the bore.
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Review and decode the candidates
Candidates are ordered by outside diameter, width, and designation. Each one is decoded back through the bore rule before it is shown.
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Complete the ordering number
Use the decoder to identify the maker-specific seal, shield, clearance, cage, and precision suffixes. Confirm the current catalog row before ordering.
Built For
- A maintenance technician measures a 25 mm motor shaft and has 52 mm of housing diameter and 15 mm of width. The finder narrows the deep groove ball ladder to the tabulated rows that fit, then the technician confirms closure and clearance in the current maker catalog.
- A designer knows the shaft bore but has not chosen between ball and roller geometry. The finder shows the tabulated envelope and load-rating spread while keeping load direction and misalignment as explicit next decisions.
- A storeroom planner has a bore, outside diameter, and width from an unidentified metric bearing. Exact-match mode returns only rows with those three dimensions, then the decoder handles maker-specific suffixes.
Features & Capabilities
How this works
The finder groups the audited boundary rows by exact bore, applies optional envelope and type filters, then sorts the survivors from smallest envelope to largest. It never builds a designation from a guessed series.
Worked example: 25 mm bore
For a 25 mm shaft, the bore code is 05. The deep groove ball ladder contains four rows. All fit the same shaft, while outside diameter, width, and load rating increase along the ladder.
What the number means
The last two digits are the ISO bore code on standard four-digit and five-digit designations. The four exceptions are 00 for 10 mm, 01 for 12 mm, 02 for 15 mm, and 03 for 17 mm. From 04 upward, multiply the code by 5. Already have a number? Decode it.
What changes across brands
The ISO basic designation describes standard boundary dimensions. The full ordering number is maker-specific because seal, shield, clearance, cage, lubricant, and precision suffixes differ. Load ratings can also differ between makers and between standard and enhanced designs.
Worked example: 25 mm bore
| Designation | Bore mm | OD mm | Width mm | Dynamic C kN | Static C0 kN |
|---|---|---|---|---|---|
| 6005 | 25 | 47 | 12 | 11.9 | 6.55 |
| 6205 | 25 | 52 | 15 | 14.8 | 7.8 |
| 6305 | 25 | 62 | 17 | 23.4 | 11.6 |
| 6405 | 25 | 80 | 21 | 35.8 | 19.3 |
Assumptions
- All dimensions are millimetres. The tool is metric only and does not convert inch sizes.
- Bore is matched exactly. A near miss is not offered.
- Outside diameter and width are treated as the space available unless exact match is turned on.
- The tables are a curated set of common sizes, not the complete ISO 15 catalog.
- Load and speed values are the source catalog's baseline for the open variant. Enhanced E and EC designs typically run 10 to 30 percent higher dynamic capacity and are a different part.
Limitations
- The finder returns basic designations only. Seal, shield, clearance, cage and precision suffixes are not selected here.
- Not every row carries a load rating or speed rating. Tapered roller rows are dimensions only because the source catalog publishes a rating under its own rating-life convention that is not the ISO 281 dynamic capacity.
- Angular contact rows are medium confidence. Vendor variations in contact angle can change outside diameter in edge cases.
- Cross-brand equivalence is not checked here. That is a separate job.
- Fit, shaft and housing tolerance, lubrication, alignment and mounting are not checked.
- An un-tabulated size returns a needs-source block, never a plausible-looking number.
- The maker's current catalog row and the physical part label control the final order.
References
- SKF Rolling Bearings, Publication 17000 EN, 2021 edition, product tables.
- SKF Bearings and Mounted Products, deep-groove radial internal-clearance table. The 24 through 30 mm bore row gives CN 5 to 20 microns and C3 13 to 28 microns, matching the 25 mm guide example. Accessed 2026-07-27.
- Timken Tapered Roller Bearing Catalog 10481, 2021, single-row metric tables, printed pp. 394-396.
- Timken Metric Tapered Roller Bearings, official metric dimensions table. The 25 mm rows independently corroborate 30205, 32205, 33205, 30305, and 32305. Accessed 2026-07-27.
- ISO 15, boundary dimensions for radial bearings.
- ISO 5753-1:2009, radial internal clearance, limited here to deep groove ball bearings.
- ISO 5593, bearing vocabulary, and ISO 281:2007, rating life, as cited in the audited bearing-type data.