61864 bearing: complete specifications & equivalents
The 61864 is a ISO 15 radial bearing sized 320 x 400 x 38 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 320 mm |
| Outer diameter D | 400 mm |
| Width B | 38 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 | 172 kN |
| Basic static load rating C0 | 255 kN |
| Fatigue load limit Pu | 5.7 kN |
| Reference speed (thermal) | 3000 rpm |
| Limiting speed (mechanical) | 1900 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 9500 g |
| Manufacturer designation | SKF 61864 |
| 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 & 61800-series range
| Bore d | 12.598 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 1.496 in |
| ISO bore code | 64 |
| Radial section height (D−d)/2 | 40 mm |
| Smallest bore in 61800-series | 1 mm |
| Largest outer diameter in 61800-series | 1820 mm |
| Width range across 61800-series | 1–140 mm |
| Bore position in 61800-series (smallest first) | 48 of 74 |
| Bore above smallest 61800-series size | 319 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61864 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
| 61864-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 320×400×38 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61864-MA | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF 61864 MA (machined brass cage, open arrangement) is the same-size execution on the 320×400×38 mm envelope with ratings within 10 % — boundary dimensions interchangeable. |
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 61864 model number is decoded
In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61864 carries bore code 64 = 320 mm. Outside diameter 400 mm and width 38 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 320 mm shaft, typical catalogue practice is a m6 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
- space-constrained gearboxes
- clutch and transmission assemblies
- robotics and automation joints
- lay shafts and idler shafts
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- raceway smearing under marginal lubrication at start-up
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- Mount this 320 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.
- The 618xx thin section at 320 mm bore has only a 40.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6264.
- The open 61864 has no lubricant retention: grease escapes and contaminants migrate straight into the 320×400×38 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61864 units.
- Deep-groove ball bearings tolerate only minutes of misalignment; if the 400 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61864.
- Shaft and housing fillets must clear the bearing chamfer so the 38 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
- The open 61864 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 61864-2Z (shields) and 61864-2RSH (contact seals), not suffix-free 61864.
- The 172/255 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 61864 bearing?
A 61864 deep-groove ball bearing has a 320 mm bore, 400 mm outer diameter and 38 mm width (12.598 × 15.748 × 1.496 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
What does no suffix on 61864 mean?
A bare 61864 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 61800 compare with other series at the same 320 mm bore?
618 is an extra-thin section: 400×38 mm, only 40.0 mm radial section at 320 mm bore, far smaller than a 6264, for space-limited layouts at the cost of load rating and misalignment tolerance.
Are 61864 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 61864 uses the same ISO 15 envelope (320×400×38 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting.
What is the SKF designation and catalogue data for 61864?
In the SKF Rolling Bearings catalogue this size is listed as 61864 — the open (unsealed) execution, 320×400×38 mm per ISO 15. Quoted values: C 172 kN, C0 255 kN, Pu 5.7 kN, limiting speed 1900 r/min, mass 9500 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61864.
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.