6405 bearing: complete specifications & equivalents
The 6405 is a ISO 15 radial bearing sized 25 x 80 x 21 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 25 mm |
| Outer diameter D | 80 mm |
| Width B | 21 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 | 35.8 kN |
| Basic static load rating C0 | 19.3 kN |
| Fatigue load limit Pu | 0.815 kN |
| Reference speed (thermal) | 20000 rpm |
| Limiting speed (mechanical) | 13000 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 540 g |
| Manufacturer designation | SKF 6405 |
| 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 | 0.984 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 0.827 in |
| ISO bore code | 05 |
| Radial section height (D−d)/2 | 27.5 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) | 6 of 21 |
| Bore above smallest 6400-series size | 15 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6405-ZZ | GENERIC-ISO | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×80×21 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 6405-2RS | GENERIC-ISO | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×80×21 mm envelope per ISO 15; seal variant differs (OPEN vs 2RS) — 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 6405 model number is decoded
In the 6400-series (ISO 15 diameter series 4) the last two digits encode the bore: 6405 carries bore code 05 = 25 mm. Outside diameter 80 mm and width 21 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 25 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
- rolling-contact fatigue spalling after the rated L10 life is exceeded
- brinelling from static overload or hammering during mounting
Selection pitfalls — read before you substitute
- At a 25 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6405; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
- The 64xx heavy section at 25 mm bore (80 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.
- The open 6405 has no lubricant retention: grease escapes and contaminants migrate straight into the 25×80×21 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- 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 6405 units.
- 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 6405.
- The open 6405 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 6405-2Z (shields) and 6405-2RSH (contact seals), not suffix-free 6405.
- The 35.8/19.3 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 6405 bearing?
A 6405 deep-groove ball bearing has a 25 mm bore, 80 mm outer diameter and 21 mm width (0.984 × 3.15 × 0.827 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields. Geometry-based estimated mass is about 486 g for a steel-cage unit; catalogue masses vary slightly with seal and cage design.
How does the 6405 bore code work?
The last two digits of 6405 are bore code 05, giving 05 × 5 = 25 mm bore. The 80 mm outside diameter and 21 mm width follow the ISO 15 diameter series, not the bore code alone.
What does no suffix on 6405 mean?
A bare 6405 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication.
How does the 6400 compare with other series at the same 25 mm bore?
The '4' is the heavy diameter series: 80×21 mm, 27.5 mm radial section at 25 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts.
What is the SKF designation and catalogue data for 6405?
In the SKF Rolling Bearings catalogue this size is listed as 6405 — the open (unsealed) execution, 25×80×21 mm per ISO 15. Quoted values: C 35.8 kN, C0 19.3 kN, Pu 0.815 kN, limiting speed 13000 r/min, mass 540 g. Brand suffixes (2Z, 2RSH) differ from the industry-neutral spelling 6405.
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.