6310-RSR bearing: complete specifications & equivalents
The 6310-RSR is a ISO 15 radial bearing sized 50 x 110 x 27 mm (bore x OD x width) with RSR sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NSK |
| Bore diameter d | 50 mm |
| Outer diameter D | 110 mm |
| Width B | 27 mm |
| Material | GCr15 |
| Seal / shield | RSR |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 68 kN |
| Basic static load rating C0 | 38.5 kN |
| Operating temperature | -40 to +150 °C |
| Mass | 1060 g |
| Manufacturer designation | NSK 6310VV |
| Standard | ISO 15 |
| Catalog version | NSK Rolling Bearings E1103 Part C |
| Last verified | 2026-09-24 |
Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24
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-RSR
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 low-drag seal lips retain the factory grease but are not liquid-tight. Treat as grease-for-life in light, dry duty; in dirty or wet positions plan replacement around contamination rather than fatigue.
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 = 68.0 kN → L10h ≈ 129,396 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-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 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 and load ratings may differ — confirm sealing and rating before substituting. |
| 6310-RSR-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6310-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6310 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6310-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6310-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6310-M | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 310 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 310-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
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-RSR model number is decoded
6310-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 110 mm outside diameter and 27 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 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. NSK's non-contact seal suffix is VV (catalogue number 6310VV), mapped here from the industry-neutral -RSR spelling; speed capability is close to the open bearing but VV is not liquid-tight.
Typical equipment & failure modes
Common applications
- material-handling equipment
- industrial fans
- industrial electric motors
- centrifugal and positive-displacement pumps
Known failure patterns
- ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)
- lip-lubricant starvation if the bearing runs dry for extended periods
- raceway smearing under marginal lubrication at start-up
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6310 with C3 for those conditions.
- 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.
- The low-drag lip of 6310-RSR barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.
- The non-contact lip of 6310-RSR does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 50 mm bore position before relying on it as sealed-for-life.
- A 50 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.
- 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.
- NSK catalogues this low-friction non-contact seal as 6310VV (suffix VV), mapped here from the industry-neutral -RSR spelling. NSK rates its speed capability close to the open bearing, but VV is not liquid-tight — for wet or fine-dust duty step up to the DDU contact seal (industry-neutral -2RS).
- The 50 mm bore puts 6310 in NSK's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty. NSK's VV non-contact seal is the high-speed choice here — DDU contact seal costs roughly 30–40% of the open-bearing speed ceiling.
- NSK rates 6310 at 68 kN dynamic (C) and 38.5 kN static (C0); this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.
- At 1060 g (1.1 kg), 6310 needs mechanical handling for mounting; NSK recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.
- The 50×110×27 mm envelope of 6310 gives a D/d ratio of 2.20 and 30.0 mm radial section height — a heavy NSK section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.
- The 68/38.5 kN load ratings, mass 1060 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6310VV on the 50×110×27 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6310 in a rated drive. NSK does not tabulate reference or limiting speeds in the E1103 Part C dimension tables used for this page — consult NSK's separate speed-rating tables before high-speed service.
- NSK's VV non-contact seal keeps frictional torque close to the open 6310; in motor duty where heat build-up matters, VV is the usual compromise between debris protection and speed capability.
- NSK does not recommend washing new shielded or sealed bearings; the rust-preventive film on open units is compatible with standard lithium greases and needs no removal unless the application demands a special fill.
Frequently asked questions
What are the dimensions of a 6310-RSR bearing?
A 6310-RSR 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 low-friction non-contact rubber seals.
How does the 6300 compare with other series at the same 50 mm bore?
The '3' is the medium diameter series: 110×27 mm, 30.0 mm radial section at 50 mm bore, carrying more load than a 6210 but needing a larger housing bore and giving up some speed.
Are 6310 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 6310 uses the same ISO 15 envelope (50×110×27 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar).
What is the NSK suffix for a sealed 6310?
NSK uses suffix DDU for the contact rubber seal (catalogue number 6310VV), VV for the non-contact rubber seal, and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NSK suffixes while keeping the 50×110×27 mm ISO 15 envelope.
What is the difference between NSK VV and DDU seals?
VV is a non-contact rubber seal: low torque, speed close to the open bearing, dust-tight but not liquid-tight. DDU is a contact rubber seal: far better exclusion of moisture and fine dust, at the cost of a lower speed ceiling and higher running torque. 6310VV keeps the same ISO 15 envelope either way.
Reviewed & verified by the MPN Base engineering desk against source catalog NSK Rolling Bearings E1103 Part C on 2026-09-24. Read our editorial & correction policy.