61930-MA bearing: complete specifications & equivalents
The 61930-MA is a ISO 15 radial bearing sized 150 x 210 x 28 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 150 mm |
| Outer diameter D | 210 mm |
| Width B | 28 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 88.4 kN |
| Basic static load rating C0 | 93 kN |
| Fatigue load limit Pu | 2.9 kN |
| Reference speed (thermal) | 6300 rpm |
| Limiting speed (mechanical) | 5300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3050 g |
| Manufacturer designation | 61930 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 | 5.906 in |
|---|---|
| Outer diameter D | 8.268 in |
| Width B | 1.102 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 30 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) | 34 of 63 |
| Bore above smallest 61900-series size | 147 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61930-2RS | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6930DDU on the same 150×210×28 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 61930-ZZ | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6930ZZ on the same 150×210×28 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 61930 | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6930 on the same 150×210×28 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 61930-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | NTN counterpart 6930 on the same 150×210×28 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 61930-2RS-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | NTN counterpart 6930LLU on the same 150×210×28 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 61930-ZZ-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | NTN counterpart 6930ZZ on the same 150×210×28 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
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 61930-MA model number is decoded
In the 61900-series, the last two digits encode the bore: 61930 carries code 30 = 150 mm (code × 5). The envelope is 150×210×28 mm (5.906×8.268×1.102 in) with a 30.0 mm radial section height, C 88.4 kN, C0 93 kN and Pu 2.9 kN. The open 61930 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 5300 r/min, catalogue mass 3050 g. A thin section saves space but leaves little margin for misalignment or shaft deflection.
Typical equipment & failure modes
Common applications
- hoists and winches
- industrial fans and blowers
- mill and kiln auxiliaries
- pulp and paper machinery
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- edge loading from shaft deflection or housing misalignment
- rolling-contact fatigue spalling once the catalogue L10 life is exceeded
Selection pitfalls — read before you substitute
- The fatigue load limit is 2.9 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- The fatigue load limit is 2.9 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- The MA suffix on 61930-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 3050 g quoted mass includes the heavier cage.
- Open 61930-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 61930-MA; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- Catalogue ratings for 61930-MA (C 88.4 kN, C0 93 kN) are SKF figures from PUB BU/P1 17000; geometry revisions can change ratings without changing the designation, so keep the catalogue edition with the specification.
- SKF Explorer deep-groove bearings of this size are produced to tight internal-geometry control; rating revisions between catalogue years do not change the designation, so keep the catalogue edition with the machine documentation.
- SKF date-codes its packaging, and greased sealed or shielded bearings carry a finite shelf life: rotate stock first-in-first-out and store boxes dry, cool and away from vibration.
Frequently asked questions
What are the dimensions of 61930-MA?
The SKF 61930 MA measures 150 mm bore × 210 mm OD × 28 mm width (5.906 × 8.268 × 1.102 in), mass about 3050 g. It is open, with no shields or seals.
How does the bore code in 61930 work?
The final two digits of 61930 are bore code 30, multiplied by 5 to give 150 mm.
How long can a greased 61930-MA be stored?
Sealed and shielded SKF units carry a finite grease shelf life: SKF recommends first-in-first-out stock rotation and dry, cool, vibration-free storage. Open units ship with rust preventive only and are greased at assembly.
What load can 61930-MA take?
Catalogue values for 61930 MA: dynamic C 88.4 kN, static C0 93 kN, fatigue limit Pu 2.9 kN. Use C in life calculation and C0 for static checks at 150 mm bore.
What is the speed rating of 61930-MA?
SKF lists a 6300 r/min thermal reference speed and a 5300 r/min mechanical limiting speed for 61930 MA; real limits also depend on lubrication and fits.
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.