W623-ZZ bearing: complete specifications & equivalents
The W623-ZZ is a ISO 15 radial bearing sized 3 x 10 x 4 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 | 3 mm |
| Outer diameter D | 10 mm |
| Width B | 4 mm |
| Material | SS440C |
| Seal / shield | ZZ |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 0.358 kN |
| Basic static load rating C0 | 0.11 kN |
| Fatigue load limit Pu | 0.005 kN |
| Reference speed (thermal) | 140000 rpm |
| Limiting speed (mechanical) | 70000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1.6 g |
| Manufacturer designation | W 623-2Z |
| 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 | 0.118 in |
|---|---|
| Outer diameter D | 0.394 in |
| Width B | 0.157 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 3.5 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) | 1 of 45 |
| Bore above smallest 6200-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| W623-2RS | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 3×10×4 mm envelope and equivalent catalogue ratings; W 623-2RS1 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 W623-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: 623 fits a 3 mm shaft (direct-number miniature spelling). Envelope 3×10×4 mm (0.118×0.394×0.157 in), C 0.358 kN, C0 0.11 kN, Pu 0.005 kN; limiting speed 70000 r/min and mass 1.6 g. SKF spells the double shield W 623-2Z (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
- chemical and marine atmospheres
- medical and laboratory devices
- small pumps handling corrosive media
- bicycle and outdoor equipment
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
- Corrosion resistance depends on clean, undamaged surfaces: never weld near W623-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 W623-ZZ inside the quoted grease temperature range.
- W-prefix stainless rings (X108CrMo17 / AISI 440C class) resist moisture and weak chemicals but will still rust in chloride-rich or salt-spray duty without protection — W623-ZZ is not marine-grade stainless.
- The stainless steel is martensitic and MAGNETIC; do not reject W623-ZZ over magnetism — only austenitic grades are non-magnetic, and those are too soft for bearing raceways.
- Do not preload W623-ZZ to silence it: a deep-groove ball bearing is not angular-contact, and axial preload only raises temperature and shortens grease life.
- At 3 mm bore, C3 clearance is the safe choice when interference fits plus temperature rise consume the CN clearance; a hot tight bearing with no residual clearance fails fast.
Frequently asked questions
What are the dimensions of the stainless W623-ZZ?
SKF W 623-2Z measures 3×10×4 mm (0.118×0.394×0.157 in), about 1.6 g, C 0.358 kN.
What does the W in W 623-2Z 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.
Are W stainless bearings waterproof?
No — the stainless rings resist moisture and weak chemicals far better than 52100 chrome steel, but salt spray, strong chlorides and unlubricated washdown duty can still corrode W623-ZZ; add seals and food-grade grease for wet positions.
Can I replace a chrome-steel bearing with stainless W623-ZZ?
The envelope matches, but stainless rates lower (C 0.358 kN for W 623-2Z); for corrosive environments that trade-off is intended, for high loads it shortens life.
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.