61944-MA bearing: complete specifications & equivalents
The 61944-MA is a ISO 15 radial bearing sized 220 x 300 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 | 220 mm |
| Outer diameter D | 300 mm |
| Width B | 38 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 151 kN |
| Basic static load rating C0 | 180 kN |
| Fatigue load limit Pu | 4.75 kN |
| Reference speed (thermal) | 4300 rpm |
| Limiting speed (mechanical) | 3600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7950 g |
| Manufacturer designation | 61944 MA |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27
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 | 8.661 in |
|---|---|
| Outer diameter D | 11.811 in |
| Width B | 1.496 in |
| ISO bore code | 44 |
| Radial section height (D−d)/2 | 40 mm |
| Smallest bore in 61900-series | 3 mm |
| Largest outer diameter in 61900-series | 1120 mm |
| Width range across 61900-series | 3–118 mm |
| Bore position in 61900-series (smallest first) | 40 of 63 |
| Bore above smallest 61900-series size | 217 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61944-ZZ | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 220×300×38 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 61944 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 61944 (open arrangement) shares the 220×300×38 mm envelope with ratings within 10 % — execution variant of the same size; 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 61944-MA model number is decoded
In the 61900-series, the last two digits encode the bore: 61944 carries code 44 = 220 mm (code × 5). The envelope is 220×300×38 mm (8.661×11.811×1.496 in) with a 40.0 mm radial section height, C 151 kN, C0 180 kN and Pu 4.75 kN. The open 61944 MA carries no shields or seals and relies on application lubrication and external sealing. The MA suffix identifies the machined brass cage execution, a separate order number from the pressed-steel version. Limiting speed 3600 r/min, catalogue mass 7950 g. A thin section saves space but leaves little margin for misalignment or shaft deflection.
Typical equipment & failure modes
Common applications
- crusher auxiliary drives
- space-constrained gearboxes
- clutch and transmission assemblies
- robotics and automation joints
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- false brinelling from vibration while the shaft stands idle
- fretting corrosion on a creeping shaft or housing seat
Selection pitfalls — read before you substitute
- Assign interference to the rotating ring: on a conventional shaft-mounted 220 mm position the inner ring rotates, so use a k5/m6 shaft seat with an H7 housing — reverse the logic if the outer ring rotates.
- Assign interference to the rotating ring: on a conventional shaft-mounted 220 mm position the inner ring rotates, so use a k5/m6 shaft seat with an H7 housing — reverse the logic if the outer ring rotates.
- The MA suffix on 61944-MA denotes a machined brass cage: it is the choice for high speeds, marginal lubrication and shock/vibration duty, and it is temperature-tolerant where polymer cages are not — the 7950 g quoted mass includes the heavier cage.
- Open 61944-MA needs external sealing at the arrangement level; in dusty housings its life depends entirely on those external seals and the regreasing schedule.
- Plan a relubrication interval for 61944-MA; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- Do not preload 61944-MA to silence it: a deep-groove ball bearing is not angular-contact, and axial preload only raises temperature and shortens grease life.
Frequently asked questions
What are the dimensions of 61944-MA?
The SKF 61944 MA measures 220 mm bore × 300 mm OD × 38 mm width (8.661 × 11.811 × 1.496 in), mass about 7950 g. It is open, with no shields or seals.
How does the bore code in 61944 work?
The final two digits of 61944 are bore code 44, multiplied by 5 to give 220 mm.
How heavy is 61944-MA?
Catalogue mass is 7950 g for 61944 MA; seal and cage executions of the same envelope differ by a few grams.
What load can 61944-MA take?
Catalogue values for 61944 MA: dynamic C 151 kN, static C0 180 kN, fatigue limit Pu 4.75 kN. Use C in life calculation and C0 for static checks at 220 mm bore.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.