6409-2RS bearing: complete specifications & equivalents
The 6409-2RS is a ISO 15 radial bearing sized 45 x 120 x 29 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 45 mm |
| Outer diameter D | 120 mm |
| Width B | 29 mm |
| Seal / shield | 2RS |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Operating temperature | -30 to +110 °C |
| Mass (geometry estimate) | 1438 g |
| Standard | ISO 15 |
| Catalog version | iso15-ed4-geometry |
| Last verified | 2026-09-23 |
Source: ISO 15 boundary-dimensions standard · extracted 2026-09-23
Standard-interchange bearing: dimensions per ISO 15; CN clearance, P0 tolerance and a stamped-steel cage are catalogue defaults unless the supplier states otherwise, and mass is a geometry-derived estimate. Brand catalogue load ratings and limiting speeds for 6409 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & 6400-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 4.724 in |
| Width B | 1.142 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 37.5 mm |
| Smallest bore in 6400-series | 10 mm |
| Largest outer diameter in 6400-series | 250 mm |
| Width range across 6400-series | 12–58 mm |
| Bore position in 6400-series (smallest first) | 10 of 21 |
| Bore above smallest 6400-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6409 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×120×29 mm envelope per ISO 15; seal variant differs (2RS vs OPEN) — confirm sealing suits the duty. |
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 6409-2RS model number is decoded
In the 6400-series (ISO 15 diameter series 4) the last two digits encode the bore: 6409 carries bore code 09 = 45 mm. Outside diameter 120 mm and width 29 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. 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
- conveyors and drives
- agricultural equipment
- fans and blowers
- electric motors
Known failure patterns
- seal-lip hardening and loss of pre-grease in sustained high-temperature service
- grease-life expiry in the sealed-for-life cavity (no relubrication path)
- false brinelling from vibration while the shaft is stationary
- fretting corrosion on a loose shaft seat
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 6409-2RS; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
- The 64xx heavy section at 45 mm bore (120 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.
- Contact seals add drag and heat: 6409-2RS runs slower and cooler-limited than the open 6409; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.
- Never wash a sealed 6409-2RS in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.
- Suffixes stack in a defined order — clearance follows the seal code, e.g. 6409-2RS-C3. No clearance suffix means normal CN clearance.
Frequently asked questions
What are the dimensions of a 6409-2RS bearing?
A 6409-2RS deep-groove ball bearing has a 45 mm bore, 120 mm outer diameter and 29 mm width (1.772 × 4.724 × 1.142 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased. Geometry-based estimated mass is about 1438 g for a steel-cage unit; catalogue masses vary slightly with seal and cage design.
How does the 6409 bore code work?
The last two digits of 6409 are bore code 09, giving 09 × 5 = 45 mm bore. The 120 mm outside diameter and 29 mm width follow the ISO 15 diameter series, not the bore code alone.
What does the 2RS suffix on 6409-2RS mean?
2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling.
How does the 6400 compare with other series at the same 45 mm bore?
The '4' is the heavy diameter series: 120×29 mm, 37.5 mm radial section at 45 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts.
Are 6409 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 6409 uses the same ISO 15 envelope (45×120×29 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 and similar).
Reviewed & verified by the MPN Base engineering desk against source catalog iso15-ed4-geometry on 2026-09-23. Read our editorial & correction policy.