6309-RSR bearing: complete specifications & equivalents
The 6309-RSR is a ISO 15 radial bearing sized 45 x 100 x 25 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 | 45 mm |
| Outer diameter D | 100 mm |
| Width B | 25 mm |
| Material | GCr15 |
| Seal / shield | RSR |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 58.5 kN |
| Basic static load rating C0 | 32 kN |
| Mass | 829 g |
| Manufacturer designation | NSK 6309VV |
| 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 | 1.772 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 0.984 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 27.5 mm |
| Smallest bore in 6300-series | 10 mm |
| Largest outer diameter in 6300-series | 500 mm |
| Width range across 6300-series | 11–95 mm |
| Bore position in 6300-series (smallest first) | 10 of 34 |
| Bore above smallest 6300-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6309 | ISO-INTERCHANGE | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | ISO 15 envelope interchange; NSK suffix VV maps to industry-neutral RSR. Verify seal design, grease and speed rating per brand catalogue. |
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 6309-RSR model number is decoded
In the 6300-series (ISO 15 diameter series 3) the last two digits encode the bore: 6309 carries bore code 09 = 45 mm. Outside diameter 100 mm and width 25 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 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude.
Typical equipment & failure modes
Common applications
- centrifugal pumps
- small gearboxes
- conveyors and drives
- agricultural equipment
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
- cage damage from operation beyond the limiting speed
- electrical pitting in VFD-driven motors without grounding protection
Selection pitfalls — read before you substitute
- At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6309-RSR; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
- The 63xx medium series gains rating at 45 mm bore through a 100 mm OD and 25 mm width; the heavier rolling elements also trade away some speed versus a 6209.
- RSR low-friction seals on 6309-RSR run faster than contact-seal 6309-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6309-2RS instead.
- The non-contact lip of 6309-RSR does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 45 mm bore position before relying on it as sealed-for-life.
- A 45 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.
- NSK catalogues this low-friction non-contact seal as 6309VV (suffix VV), the NSK equivalent of the industry-neutral -RSR spelling on this page. VV is not liquid-tight; NSK's contact-seal suffix DDU (industry-neutral -2RS) is the choice for wet or fine-dust duty.
- The 58.5/32 kN ratings, mass 829 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6309VV; this seal/size combination has no counterpart in the SKF 17000 extract used elsewhere on this site, so the page rests on a single manufacturer source — internal geometry and ratings legitimately differ between brands, so re-verify before substituting in a rated drive.
Frequently asked questions
What are the dimensions of a 6309-RSR bearing?
A 6309-RSR deep-groove ball bearing has a 45 mm bore, 100 mm outer diameter and 25 mm width (1.772 × 3.937 × 0.984 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals.
How does the 6309 bore code work?
The last two digits of 6309 are bore code 09, giving 09 × 5 = 45 mm bore. The 100 mm outside diameter and 25 mm width follow the ISO 15 diameter series, not the bore code alone.
What does the RSR suffix on 6309-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.
How does the 6300 compare with other series at the same 45 mm bore?
The '3' is the medium diameter series: 100×25 mm, 27.5 mm radial section at 45 mm bore, carrying more load than a 6209 but needing a larger housing bore and giving up some speed.
What is the NSK designation and catalogue data for 6309-RSR?
In the NSK Rolling Bearings catalogue (E1103 Part C) this size is listed as 6309VV — two low-friction non-contact rubber seals (NSK suffix VV), 45×100×25 mm per ISO 15. Quoted values: C 58.5 kN, C0 32 kN, mass 829 g. The industry-neutral page spelling 6309-RSR follows the seal-suffix convention used across this site, not NSK order-number spelling. Reference and limiting speeds are not tabulated in the E1103 dimension tables used here; consult NSK speed tables before high-speed service.
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.