6310-ZZ bearing: complete specifications & equivalents
The 6310-ZZ is a ISO 15 radial bearing sized 50 x 110 x 27 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 | 50 mm |
| Outer diameter D | 110 mm |
| Width B | 27 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 | 65 kN |
| Basic static load rating C0 | 38 kN |
| Fatigue load limit Pu | 1.6 kN |
| Reference speed (thermal) | 13000 rpm |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 1100 g |
| Manufacturer designation | SKF 6310-2Z |
| 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 | 1.969 in |
|---|---|
| Outer diameter D | 4.331 in |
| Width B | 1.063 in |
| ISO bore code | 10 |
| Radial section height (D−d)/2 | 30 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) | 17 of 40 |
| Bore above smallest 6300-series size | 48 mm |
Mounting, lubrication & life for 6310-ZZ
Recommended fits & mounting
- Rotating inner ring on a 50 mm shaft: k5; housing bore H7 for normal stationary-load outer rings. Reverse the logic if the outer ring rotates.
- Fit by induction heating (max 120 °C) where practical — never drive the ring home through the rolling elements.
- Keep shaft and housing fillet radii below the bearing chamfer so the 27 mm-wide ring seats square on its shoulder.
Lubrication strategy
Non-contact metal shields block coarse debris while running nearly as cool as open. No relubrication path on the standard execution; the shield cavity grease ages even though the steel is still serviceable.
Worked L10 life example (illustrative duty)
For ball bearings, L10h = (C/P)3 · 106 / (60·n). Taking an example radial equivalent load P = 3 kN at n = 1,500 r/min (a small belted motor duty — substitute the real equivalent load from the application calculation):
C = 65.0 kN → L10h ≈ 113,014 hours
Choosing a section at the same 50 mm bore
| Series | Open execution | OD × width | C (kN) | Limiting speed (r/min) |
|---|---|---|---|---|
| 60xx | 6010-NSK | 80 × 16 | 24.0 | – |
| 62xx | 6210-NSK | 90 × 20 | 38.5 | – |
| 63xx | 6310-NSK | 110 × 27 | 68.0 | – |
| 64xx | 6410-NTN | 130 × 31 | 92.0 | 5,700 |
| 618xx | 61810-NSK | 65 × 7 | 7.0 | – |
| 619xx | 61910-NSK | 72 × 12 | 16.0 | – |
| 160xx | 16010 | 80 × 10 | 14.7 | 8,400 |
A larger section is not a drop-in swap — OD and width change — and same-envelope seal variants are compared on the 50×110×27 envelope page. Match meaning, not the size chart alone: see what the cross-reference levels mean.
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6310 | ISO 15 | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting. |
| 6310-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant differs (ZZ vs 2RS) — confirm sealing suits the duty. |
| 6310-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — confirm sealing suits the duty. |
| 6310-RSR | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant differs (ZZ vs RSR) — confirm sealing suits the duty. |
| 6310-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. |
| 6310-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant differs (ZZ vs 2RS) — confirm sealing suits the duty. |
| 6310-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — confirm sealing suits the duty. |
| 6310-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant differs (ZZ vs RSR) — confirm sealing suits the duty. |
| 6310-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. |
| 7310 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| NU310 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| 21310 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| 6310-M | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF 6310 M (machined brass cage, open arrangement) is the same-size execution on the 50×110×27 mm envelope with ratings within 10 % — boundary dimensions interchangeable. |
| 310 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF 310 shares the 50×110×27 mm envelope but catalogue C/C0 differ — envelope match only after a load check. |
| 310-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF 310-2Z shares the 50×110×27 mm envelope but catalogue C/C0 differ — envelope match only after a load check. |
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 6310-ZZ model number is decoded
In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6310 carries bore code 10 = 50 mm. Outside diameter 110 mm and width 27 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. SKF's own suffix is 2Z (this page's industry-neutral spelling is -ZZ); catalogue number 6310-2Z.
Typical equipment & failure modes
Common applications
- conveyor drives
- material-handling equipment
- industrial fans
- industrial electric motors
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
- brinelling from static overload or hammering during mounting
- false brinelling from vibration while the shaft is stationary
Selection pitfalls — read before you substitute
- Interference on a 50 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6310 with C3 clearance and re-check the residual value after mounting.
- The 63xx medium section at 50 mm bore gains dynamic rating through larger rolling elements on a 110 mm OD; the penalty is mass and a lower limiting speed than the 6210 — do not specify it for speed-critical shafts.
- ZZ shields are non-contact: 6310-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6310-2RS for that.
- Do not wash 6310-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.
- Deep-groove ball bearings tolerate only minutes of misalignment; if the 110 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6310-ZZ.
- Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
- SKF spells the shielded version 6310-2Z (one shield: 6310-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 6310-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 6310-2Z for high-contamination positions.
- The 65/38 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 6310-ZZ bearing?
A 6310-ZZ deep-groove ball bearing has a 50 mm bore, 110 mm outer diameter and 27 mm width (1.969 × 4.331 × 1.063 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields.
What internal clearance does 6310-ZZ have?
Unless a clearance suffix says otherwise, 6310-ZZ is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6310 and verify the residual clearance after mounting.
How should 6310-ZZ be mounted?
Apply the mounting force to the ring being fitted: on a 50 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals.
What lubrication does 6310-ZZ need?
6310-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.
What is the SKF designation and catalogue data for 6310-ZZ?
In the SKF Rolling Bearings catalogue this size is listed as 6310-2Z — two non-contact sheet-metal shields, 50×110×27 mm per ISO 15. Quoted values: C 65 kN, C0 38 kN, Pu 1.6 kN, limiting speed 6700 r/min, mass 1100 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 6310-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.