6307-RSR bearing: complete specifications & equivalents
The 6307-RSR is a ISO 15 radial bearing sized 35 x 80 x 21 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 | 35 mm |
| Outer diameter D | 80 mm |
| Width B | 21 mm |
| Material | GCr15 |
| Seal / shield | RSR |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 36.5 kN |
| Basic static load rating C0 | 19.2 kN |
| Operating temperature | -40 to +150 °C |
| Mass | 464 g |
| Manufacturer designation | NSK 6307VV |
| 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 | 1.378 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 0.827 in |
| ISO bore code | 07 |
| Radial section height (D−d)/2 | 22.5 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) | 14 of 40 |
| Bore above smallest 6300-series size | 33 mm |
Mounting, lubrication & life for 6307-RSR
Recommended fits & mounting
- Rotating inner ring on a 35 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 21 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 = 36.5 kN → L10h ≈ 20,011 hours
Choosing a section at the same 35 mm bore
| Series | Open execution | OD × width | C (kN) | Limiting speed (r/min) |
|---|---|---|---|---|
| 60xx | 6007-FAG | 62 × 14 | 17.5 | 17,700 |
| 62xx | 6207-FAG | 72 × 17 | 28.0 | 15,000 |
| 63xx | 6307-FAG | 80 × 21 | 37.0 | 13,600 |
| 64xx | 6407-FAG | 100 × 25 | 56.0 | 9,500 |
| 618xx | 61807-FAG | 47 × 7 | 4.7 | 21,600 |
| 619xx | 61907-FAG | 55 × 10 | 10.9 | 17,800 |
| 160xx | 16007 | 62 × 9 | 12.3 | 16,700 |
A larger section is not a drop-in swap — OD and width change — and same-envelope seal variants are compared on the 35×80×21 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 |
|---|---|---|---|
| 6307-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6307-2RS-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6307-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6307-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6307-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6307-RSR-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6307-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6307 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6307-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6307-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6307-M | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W6307-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 307 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 307-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 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 6307-RSR model number is decoded
In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6307 carries bore code 07 = 35 mm. Outside diameter 80 mm and width 21 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NSK's non-contact seal suffix is VV (catalogue number 6307VV), 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
- electric motors
- centrifugal pumps
- small gearboxes
- conveyors and drives
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
- fretting corrosion on a loose shaft seat
- cage damage from operation beyond the limiting speed
Selection pitfalls — read before you substitute
- A 35 mm shaft for 6307 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.
- The 63xx medium series gains rating at 35 mm bore through a 80 mm OD and 21 mm width; the heavier rolling elements also trade away some speed versus a 6207.
- RSR low-friction seals on 6307-RSR run faster than contact-seal 6307-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6307-2RS instead.
- The low-drag lip of 6307-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.
- 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.
- Deep-groove ball bearings tolerate only minutes of misalignment; if the 80 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6307-RSR.
- NSK catalogues this low-friction non-contact seal as 6307VV (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 35 mm bore puts 6307 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 6307 at 36.5 kN dynamic (C) and 19.2 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 464 g, 6307 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.
- The 35×80×21 mm envelope of 6307 gives a D/d ratio of 2.29 and 22.5 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 36.5/19.2 kN load ratings, mass 464 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6307VV on the 35×80×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6307 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.
- When replacing a failed unit, inspect the shaft and housing seats before fitting the new 6307 — a new bearing pressed onto a worn or oval seat reproduces the original failure mode in a fraction of its expected life.
- NSK supplies its sealed units pre-greased for general duty between roughly -10 and +110 °C; low-temperature, food-grade and high-temperature fills are special executions — ask at order time, because DDU/VV units are not designed to be opened and repacked.
Frequently asked questions
What are the dimensions of a 6307-RSR bearing?
A 6307-RSR deep-groove ball bearing has a 35 mm bore, 80 mm outer diameter and 21 mm width (1.378 × 3.15 × 0.827 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals.
How does the 6307 bore code work?
The last two digits of 6307 are bore code 07, giving 07 × 5 = 35 mm bore. The 80 mm outside diameter and 21 mm width follow the ISO 15 diameter series, not the bore code alone.
What does the RSR suffix on 6307-RSR mean?
RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments.
What is the NSK suffix for a sealed 6307?
NSK uses suffix DDU for the contact rubber seal (catalogue number 6307VV), 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 35×80×21 mm ISO 15 envelope.
Does NSK offer 6307 with C3 clearance?
NSK lists C3 (and C4) internal-clearance options for most deep-groove sizes under the same base designation; the clearance is fixed at manufacture, so specify it at order time rather than planning to adjust later.
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.