W629-ZZ bearing: complete specifications & equivalents
The W629-ZZ is a ISO 15 radial bearing sized 9 x 26 x 8 mm (bore x OD x width) with ZZ sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 9 mm |
| Outer diameter D | 26 mm |
| Width B | 8 mm |
| Material | SS440C |
| Seal / shield | ZZ |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 3.97 kN |
| Basic static load rating C0 | 1.96 kN |
| Fatigue load limit Pu | 0.083 kN |
| Reference speed (thermal) | 67000 rpm |
| Limiting speed (mechanical) | 32000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 19 g |
| Manufacturer designation | W 629-2Z |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & 6200-series range
| Bore d | 0.354 in |
|---|---|
| Outer diameter D | 1.024 in |
| Width B | 0.315 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 8.5 mm |
| Smallest bore in 6200-series | 3 mm |
| Largest outer diameter in 6200-series | 540 mm |
| Width range across 6200-series | 2.5–85 mm |
| Bore position in 6200-series (smallest first) | 6 of 45 |
| Bore above smallest 6200-series size | 6 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 629 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 9×26×8 mm envelope, but the stainless and chrome-steel executions carry different catalogue ratings (3.97/1.96 kN vs 4.75/1.96 kN) — envelope match, not a load-rating equivalent; choose by corrosion versus load duty. |
| 629-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 9×26×8 mm envelope, but the stainless and chrome-steel executions carry different catalogue ratings (3.97/1.96 kN vs 4.75/1.96 kN) — envelope match, not a load-rating equivalent; choose by corrosion versus load duty. |
| 629-RSR | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 9×26×8 mm envelope, but the stainless and chrome-steel executions carry different catalogue ratings (3.97/1.96 kN vs 4.75/1.96 kN) — envelope match, not a load-rating equivalent; choose by corrosion versus load duty. |
| 629-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 9×26×8 mm envelope, but the stainless and chrome-steel executions carry different catalogue ratings (3.97/1.96 kN vs 4.75/1.96 kN) — envelope match, not a load-rating equivalent; choose by corrosion versus load duty. |
| W629-2RS | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 9×26×8 mm envelope and equivalent catalogue ratings; W 629-2RS1 is the two contact elastomer seals execution of this size — boundary dimensions interchangeable, only the seal/shield/cage execution differs. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the W629-ZZ model number is decoded
The W prefix denotes SKF stainless steel deep-groove bearings (X108CrMo17 / AISI 440C class rings). In the 6200-series, the final digit is the bore in millimetres: 629 fits a 9 mm shaft (direct-number miniature spelling). Envelope 9×26×8 mm (0.354×1.024×0.315 in), C 3.97 kN, C0 1.96 kN, Pu 0.083 kN; limiting speed 32000 r/min and mass 19 g. SKF spells the double shield W 629-2Z (suffix 2Z); the shields are non-contact, retain grease and block coarse debris but are not liquid-tight. Stainless is chosen for corrosion and washdown duty, not for extra load — the same-envelope chrome-steel bearing rates higher.
Typical equipment & failure modes
Common applications
- small pumps handling corrosive media
- bicycle and outdoor equipment
- appliances exposed to moisture
- food and beverage conveyors
Known failure patterns
- surface staining and pitting when even the stainless steel is left unlubricated in salty or acidic duty
- seal and grease failure before the rings corrode in sustained washdown service
- fine-particle abrasion when non-contact shields let dust through in a dirty environment
- grease aging inside the shielded cavity with no relubrication path
Selection pitfalls — read before you substitute
- Stainless bearings carry lower load ratings than chrome steel of the same envelope: W629-ZZ is quoted at C 3.97 kN versus the 8 mm-wide 52100 version — do not swap on dimensions alone.
- Food, pharmaceutical and washdown positions need food-grade grease (e.g. NSF H1 registered) inside W629-ZZ; standard fill is industrial grease unless specified otherwise.
- Corrosion resistance depends on clean, undamaged surfaces: never weld near W629-ZZ or scratch the raceways during mounting, since the damaged spot starts corrosion.
- Temperatures above roughly 300 °C temper the stainless races; even standard greases fail far earlier — keep W629-ZZ inside the quoted grease temperature range.
- Assign interference to the rotating ring: on a conventional shaft-mounted 9 mm position the inner ring rotates, so use a k5/m6 shaft seat with an H7 housing — reverse the logic if the outer ring rotates.
- Mount by heating the inner ring (max 120 °C) — driving W629-ZZ home through the outer ring or balls brinells the raceways.
Frequently asked questions
What are the dimensions of the stainless W629-ZZ?
SKF W 629-2Z measures 9×26×8 mm (0.354×1.024×0.315 in), about 19 g, C 3.97 kN.
What does the W in W 629-2Z mean?
W is the SKF prefix for stainless steel deep-groove bearings (rings in X108CrMo17 / AISI 440C class); the rest of the designation follows the normal series and bore rules.
Where is W629-ZZ typically used?
Food and packaging machines, pharmaceutical equipment, washdown conveyors, chemical and marine-atmosphere drives and appliances exposed to moisture.
What grease is supplied in W629-ZZ?
Sealed units are pre-greased for life; for food or pharmaceutical duty order (or re-grease before service) with an NSF H1 registered food-grade grease.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.