6409 bearing: complete specifications & equivalents
The 6409 is a ISO 15 radial bearing sized 45 x 120 x 29 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 45 mm |
| Outer diameter D | 120 mm |
| Width B | 29 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 76.1 kN |
| Basic static load rating C0 | 45 kN |
| Fatigue load limit Pu | 1.9 kN |
| Reference speed (thermal) | 13000 rpm |
| Limiting speed (mechanical) | 8500 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 1550 g |
| Manufacturer designation | SKF 6409 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-24 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-24
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
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 |
|---|---|---|---|
| 6409-2RS | GENERIC-ISO | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×120×29 mm envelope per ISO 15; seal variant differs (OPEN vs 2RS) — confirm sealing suits the duty. |
| 6409-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×120×29 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 6409-ZZ | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×120×29 mm envelope per ISO 15; seal variant (OPEN vs ZZ) and load ratings 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 6409 model number is decoded
In the 6400-series (diameter series 4 of ISO 15) 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. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. 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. In the SKF catalogue this open execution carries the bare designation; protected variants are ordered separately as -2Z and -2RSH.
Typical equipment & failure modes
Common applications
- fans and blowers
- electric motors
- centrifugal pumps
- small gearboxes
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- electrical pitting in VFD-driven motors without grounding protection
- raceway smearing under marginal lubrication at start-up
Selection pitfalls — read before you substitute
- Sizes around 45 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6409.
- 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.
- Storage matters for open bearings: 6409 leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.
- Open bearings tolerate the highest speeds in the 6400-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6409 units.
- 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.
- Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 29 mm-wide ring of 6409 drags the lip and overheats it.
- The open 6409 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 6409-2Z (shields) and 6409-2RSH (contact seals), not suffix-free 6409.
- The 76.1/45 kN ratings here are SKF Explorer-class figures from catalogue PUB BU/P1 17000/1 EN (Oct 2018); SKF can revise internal geometry and ratings without changing the designation, so treat the catalogue version and date as part of the specification and re-verify for critical drives.
Frequently asked questions
What are the dimensions of a 6409 bearing?
A 6409 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 an open bearing with no seals or shields.
How should 6409 be mounted?
Apply the mounting force to the ring being fitted: on a 45 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals.
What lubrication does 6409 need?
The open 6409 is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval.
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 is the SKF designation and catalogue data for 6409?
In the SKF Rolling Bearings catalogue this size is listed as 6409 — the open (unsealed) execution, 45×120×29 mm per ISO 15. Quoted values: C 76.1 kN, C0 45 kN, Pu 1.9 kN, limiting speed 8500 r/min, mass 1550 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 6409.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-24. Read our editorial & correction policy.