6320-ZZ bearing: complete specifications & equivalents
The 6320-ZZ is a ISO 15 radial bearing sized 100 x 215 x 47 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 | 100 mm |
| Outer diameter D | 215 mm |
| Width B | 47 mm |
| Material | GCr15 |
| Seal / shield | ZZ |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 174 kN |
| Basic static load rating C0 | 140 kN |
| Fatigue load limit Pu | 4.75 kN |
| Reference speed (thermal) | 6700 rpm |
| Limiting speed (mechanical) | 3400 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 7300 g |
| Manufacturer designation | SKF 6320-2Z |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-25 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-24
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 & 6300-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 1.85 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 57.5 mm |
| Smallest bore in 6300-series | 2 mm |
| Largest outer diameter in 6300-series | 500 mm |
| Width range across 6300-series | 3–95 mm |
| Bore position in 6300-series (smallest first) | 27 of 40 |
| Bore above smallest 6300-series size | 98 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6320 | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — confirm sealing suits the duty. |
| 6320-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant differs (ZZ vs 2RS) — confirm sealing suits the duty. |
| 6320-RSR | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant differs (ZZ vs RSR) — confirm sealing suits the duty. |
| 6320-ZZ-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 6320-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant differs (ZZ vs 2RS) — confirm sealing suits the duty. |
| 6320-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — confirm sealing suits the duty. |
| 6320-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 100×215×47 mm envelope per ISO 15; seal variant differs (ZZ vs RSR) — confirm sealing suits the duty. |
| 6320-ZZ-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 7320 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| NU320 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| 21320 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| 6320-M | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF 6320 M (machined brass cage, open arrangement) is the same-size execution on the 100×215×47 mm envelope with ratings within 10 % — boundary dimensions interchangeable. |
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 6320-ZZ model number is decoded
6320-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 20 by five gives the 100 mm bore; the 215 mm outside diameter and 47 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 100 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. SKF's own suffix is 2Z (this page's industry-neutral spelling is -ZZ); catalogue number 6320-2Z.
Typical equipment & failure modes
Common applications
- large gearboxes
- industrial fans and blowers
- hoists and winches
- heavy conveyors
Known failure patterns
- fine-particle abrasion when non-contact shields let dust past in dirty duty
- grease aging in the shield-for-life cavity with no relubrication path
- fretting corrosion on a loose shaft seat
- cage damage from operation beyond the limiting speed
Selection pitfalls — read before you substitute
- Large bores like the 100 mm of 6320-ZZ demand clean, burr-free seats; one raised burr under a ring this size cocks the bearing and concentrates load at the raceway edge, cutting life drastically.
- The 63xx medium series gains rating at 100 mm bore through a 215 mm OD and 47 mm width; the heavier rolling elements also trade away some speed versus a 6220.
- ZZ shields are non-contact: 6320-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6320-2RS for that.
- Do not wash 6320-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.
- Never mix components between two 6320-ZZ units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
- Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
- SKF spells the shielded version 6320-2Z (one shield: 6320-Z), not "-ZZ": the suffix language differs by brand even though the ISO envelope is identical, so quote the brand designation when ordering.
- The single-shield execution 6320-Z is a distinct order number in catalogue 17000: it suits open gears or oil-bath arrangements where the unshielded face faces the lubricant, and it is not interchangeable with the double-shield 6320-2Z for high-contamination positions.
- The 174/140 kN ratings here are SKF Explorer-class figures from catalogue PUB BU/P1 17000/1 EN (Oct 2018); SKF can revise internal geometry and ratings without changing the designation, so treat the catalogue version and date as part of the specification and re-verify for critical drives.
Frequently asked questions
What are the dimensions of a 6320-ZZ bearing?
A 6320-ZZ deep-groove ball bearing has a 100 mm bore, 215 mm outer diameter and 47 mm width (3.937 × 8.465 × 1.85 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields.
What lubrication does 6320-ZZ need?
6320-ZZ is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it.
How does the 6320 bore code work?
The last two digits of 6320 are bore code 20, giving 20 × 5 = 100 mm bore. The 215 mm outside diameter and 47 mm width follow the ISO 15 diameter series, not the bore code alone.
What does the ZZ suffix on 6320-ZZ mean?
ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing.
What is the SKF designation and catalogue data for 6320-ZZ?
In the SKF Rolling Bearings catalogue this size is listed as 6320-2Z — two non-contact sheet-metal shields, 100×215×47 mm per ISO 15. Quoted values: C 174 kN, C0 140 kN, Pu 4.75 kN, limiting speed 3400 r/min, mass 7300 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 6320-ZZ.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-25. Read our editorial & correction policy.