628-8-ZZ bearing: complete specifications & equivalents
The 628-8-ZZ is a ISO 15 radial bearing sized 8 x 16 x 5 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 | 8 mm |
| Outer diameter D | 16 mm |
| Width B | 5 mm |
| Material | GCr15 |
| Seal / shield | ZZ |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 1.33 kN |
| Basic static load rating C0 | 0.57 kN |
| Fatigue load limit Pu | 0.024 kN |
| Reference speed (thermal) | 90000 rpm |
| Limiting speed (mechanical) | 45000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3.6 g |
| Manufacturer designation | 628/8-2Z |
| 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 & 62800-series range
| Bore d | 0.315 in |
|---|---|
| Outer diameter D | 0.63 in |
| Width B | 0.197 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 4 mm |
| Smallest bore in 62800-series | 5 mm |
| Largest outer diameter in 62800-series | 24 mm |
| Width range across 62800-series | 4–8 mm |
| Bore position in 62800-series (smallest first) | 4 of 5 |
| Bore above smallest 62800-series size | 3 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 628-8-2RS | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 8×16×5 mm envelope and equivalent catalogue ratings; 628/8-2RS1 is the two contact elastomer seals execution of this size — boundary dimensions interchangeable, only the seal/shield/cage execution differs. |
| W628-8-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 8×16×5 mm envelope, but the stainless and chrome-steel executions carry different catalogue ratings (1.33/0.57 kN vs 0.715/0.3 kN) — envelope match, not a load-rating equivalent; choose by corrosion versus load duty. |
| W628-8-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 8×16×5 mm envelope, but the stainless and chrome-steel executions carry different catalogue ratings (1.33/0.57 kN vs 0.715/0.3 kN) — envelope match, not a load-rating equivalent; choose by corrosion versus load duty. |
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 628-8-ZZ model number is decoded
In the miniature 62800-series, the bore is written directly after the slash as 8 mm (bores below 10 mm use the slash spelling). The envelope is 8×16×5 mm (0.315×0.63×0.197 in) with a 4.0 mm radial section height, C 1.33 kN, C0 0.57 kN and Pu 0.024 kN. SKF spells the double shield 628/8-2Z (suffix 2Z); the shields are non-contact, retain grease and block coarse debris but are not liquid-tight. Limiting speed 45000 r/min, catalogue mass 3.6 g. A thin section saves space but leaves little margin for misalignment or shaft deflection.
Typical equipment & failure modes
Common applications
- hand-held power tools
- domestic appliances
- instrument and encoder drives
- model-making and hobby mechanics
Known failure patterns
- fine-particle abrasion when non-contact shields let dust through in a dirty environment
- grease aging inside the shielded cavity with no relubrication path
- electrical pitting in VFD-driven motors without shaft grounding
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- At 8 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.
- Mount by heating the inner ring (max 120 °C) — driving 628-8-ZZ home through the outer ring or balls brinells the raceways.
- Shields on 628-8-ZZ are non-contact: chips and coarse dust stay out, but water passes straight through — specify the sealed 628/8-2RS for washdown duty.
- Do not pry the caps off 628-8-ZZ to repack it; shield/seal damage leaves a gap that throws grease and admits dirt.
- Fillet radii must clear the 628-8-ZZ chamfer so the 5 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
- Assign interference to the rotating ring: on a conventional shaft-mounted 8 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.
Frequently asked questions
What are the dimensions of 628-8-ZZ?
The SKF 628/8-2Z measures 8 mm bore × 16 mm OD × 5 mm width (0.315 × 0.63 × 0.197 in), mass about 3.6 g. It has two non-contact sheet-metal shields.
Why is there a slash in the designation 628/8-2Z?
The slash writes a bore that falls outside the two-digit code table: 628/8 means 8 mm bore. The site slug 628-8-ZZ replaces the slash with a hyphen.
What load can 628-8-ZZ take?
Catalogue values for 628/8-2Z: dynamic C 1.33 kN, static C0 0.57 kN, fatigue limit Pu 0.024 kN. Use C in life calculation and C0 for static checks at 8 mm bore.
What is the speed rating of 628-8-ZZ?
SKF lists a 90000 r/min thermal reference speed and a 45000 r/min mechanical limiting speed for 628/8-2Z; real limits also depend on lubrication and fits.
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.