61938 bearing: complete specifications & equivalents
The 61938 is a ISO 15 radial bearing sized 190 x 260 x 33 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 190 mm |
| Outer diameter D | 260 mm |
| Width B | 33 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 | 117 kN |
| Basic static load rating C0 | 134 kN |
| Fatigue load limit Pu | 3.8 kN |
| Reference speed (thermal) | 5000 rpm |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 4500 g |
| Manufacturer designation | SKF 61938 |
| 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 & 61900-series range
| Bore d | 7.48 in |
|---|---|
| Outer diameter D | 10.236 in |
| Width B | 1.299 in |
| ISO bore code | 38 |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in 61900-series | 10 mm |
| Largest outer diameter in 61900-series | 420 mm |
| Width range across 61900-series | 6–56 mm |
| Bore position in 61900-series (smallest first) | 29 of 35 |
| Bore above smallest 61900-series size | 180 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61938 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 61938 model number is decoded
In the 61900-series (ISO 15 diameter series 9) the last two digits encode the bore: 61938 carries bore code 38 = 190 mm. Outside diameter 260 mm and width 33 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 190 mm shaft, typical catalogue practice is a m6 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude.
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
- fretting corrosion on a loose shaft seat
- cage damage from operation beyond the limiting speed
Selection pitfalls — read before you substitute
- Mount this 190 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 619xx thin section (35.0 mm section height at 190 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
- The open 61938 has no lubricant retention: grease escapes and contaminants migrate straight into the 190×260×33 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61938 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.
- The open 61938 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 61938-2Z (shields) and 61938-2RSH (contact seals), not suffix-free 61938.
- The 117/134 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 61938 bearing?
A 61938 deep-groove ball bearing has a 190 mm bore, 260 mm outer diameter and 33 mm width (7.48 × 10.236 × 1.299 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
How does the 61938 bore code work?
The last two digits of 61938 are bore code 38, giving 38 × 5 = 190 mm bore. The 260 mm outside diameter and 33 mm width follow the ISO 15 diameter series, not the bore code alone.
What does no suffix on 61938 mean?
A bare 61938 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 61900 compare with other series at the same 190 mm bore?
619 is a thin section one step above 618: 260×33 mm with a 35.0 mm radial section at 190 mm bore; a 6238 on the same bore is substantially larger and more heavily rated.
What is the SKF designation and catalogue data for 61938?
In the SKF Rolling Bearings catalogue this size is listed as 61938 — the open (unsealed) execution, 190×260×33 mm per ISO 15. Quoted values: C 117 kN, C0 134 kN, Pu 3.8 kN, limiting speed 3200 r/min, mass 4500 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61938.
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.