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.

Bearing dimension schematic Front view shows outer diameter D and bore d; side section shows width B. D = 80 mm d = 35 B = 21 mm side section front view
Principal dimensions: bore d 35 mm, outer diameter D 80 mm, width B 21 mm. Schematic, not to scale.

Specification table

ParameterValue
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 d1.378 in
Outer diameter D3.15 in
Width B0.827 in
ISO bore code07
Radial section height (D−d)/222.5 mm
Smallest bore in 6300-series2 mm
Largest outer diameter in 6300-series500 mm
Width range across 6300-series3–95 mm
Bore position in 6300-series (smallest first)14 of 40
Bore above smallest 6300-series size33 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

SeriesOpen executionOD × widthC (kN)Limiting speed (r/min)
60xx6007-FAG62 × 1417.517,700
62xx6207-FAG72 × 1728.015,000
63xx6307-FAG80 × 2137.013,600
64xx6407-FAG100 × 2556.09,500
618xx61807-FAG47 × 74.721,600
619xx61907-FAG55 × 1010.917,800
160xx1600762 × 912.316,700

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 modelBrandMatch levelNote
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.