QJ-210-MA bearing: complete specifications & equivalents
The QJ-210-MA is a ISO 15 radial bearing sized 50 x 90 x 20 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 50 mm |
| Outer diameter D | 90 mm |
| Width B | 20 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 65.5 kN |
| Basic static load rating C0 | 61 kN |
| Fatigue load limit Pu | 2.6 kN |
| Limiting speed (mechanical) | 13000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 590 g |
| Manufacturer designation | QJ 210 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 & QJ200-series range
| Bore d | 1.969 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 0.787 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in QJ200-series | 15 mm |
| Largest outer diameter in QJ200-series | 360 mm |
| Width range across QJ200-series | 11–58 mm |
| Bore position in QJ200-series (smallest first) | 8 of 29 |
| Bore above smallest QJ200-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 7210-BE-2RZP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×90×20 mm envelope, but catalogue C/C0 differ between executions (65.5/61 kN vs 37.7/28.5 kN) — boundary dimensions match, not a load-rating equivalent. |
| 7210-BEP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×90×20 mm envelope, but catalogue C/C0 differ between executions (65.5/61 kN vs 37.7/28.5 kN) — boundary dimensions match, not a load-rating equivalent. |
| 7210-BECBP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×90×20 mm envelope, but catalogue C/C0 differ between executions (65.5/61 kN vs 40/31 kN) — boundary dimensions match, not a load-rating equivalent. |
| 7210-BECBPH | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×90×20 mm envelope, but catalogue C/C0 differ between executions (65.5/61 kN vs 40/31 kN) — boundary dimensions match, not a load-rating equivalent. |
| 7210-BECBM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×90×20 mm envelope, but catalogue C/C0 differ between executions (65.5/61 kN vs 40/31 kN) — boundary dimensions match, not a load-rating equivalent. |
| 7210-BECBY | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×90×20 mm envelope, but catalogue C/C0 differ between executions (65.5/61 kN vs 41.5/33.5 kN) — boundary dimensions match, not a load-rating equivalent. |
| 7210-ACCBM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×90×20 mm envelope, but catalogue C/C0 differ between executions (65.5/61 kN vs 45.5/35.5 kN) — boundary dimensions match, not a load-rating equivalent. |
| 7210 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF SKF 7210 BEP shares the 50×90×20 mm angular-contact envelope, but catalogue C/C0 differ (65.5/61 kN vs 37.7/28.5 kN) — envelope match, not a load-rating equivalent. |
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 QJ-210-MA model number is decoded
QJ 210 MA is SKF's 50 mm-bore QJ four-point contact ball bearing of the QJ200 series, 50×90×20 mm, with a two-piece inner ring for bidirectional axial location beside a radial bearing. QJ identifies a four-point contact ball bearing with a two-piece inner ring: the gothic-arch raceways seat each ball at four points, giving axial location in both directions while a paired radial bearing carries the radial load. machined brass cage, outer-ring-centred (suffix MA), which guides on the outer ring rather than on the balls. Envelope 50×90×20 mm (1.969×3.543×0.787 in), 20.0 mm radial section height, C 65.5 kN, C0 61 kN, Pu 2.6 kN.SKF publishes only the 13,000 r/min limiting speed for this execution, catalogue mass 590 g. Mass and section check: 590 g inside the 50×90×20 mm outline leaves a 20.0 mm radial section, and the 61 kN static rating is 0.93× the dynamic rating — plan static safety and minimum load against those numbers rather than against sister executions. Load balance: C0 61 kN against C 65.5 kN gives a 0.93 ratio, typical of a four-point thrust-oriented design; Pu 2.6 kN enters the SKF adjusted-life equation rather than the basic rating life. Speed-ratio note for this exact unit: no thermal reference speed is listed (seal/grease life governs), so the 13,000 r/min limiting value is the single published ceiling. Plain outer-ring execution: this order number is delivered without N2 locating slots, so anti-rotation is solved in the housing instead — a shoulder dog, a spring-loaded key, a cover feature or an interference-free circlip arrangement. Because the outer ring deliberately runs with radial clearance and a small axial float gap, omitting positive anti-rotation invites seat fretting; the slotted N2 order number is the alternative when the housing can provide engagement pins.
Typical equipment & failure modes
Common applications
- gearbox shafts where one QJ locates axially in both directions beside a radial bearing
- screw and worm drives
- pump thrust positions
Known failure patterns
- cage wear from speed above the limiting value with thin or aged lubricant
- ball skidding when the Fa/Fr 1,27 load-ratio condition is not met and the balls contact both sides of one raceway
- outer-ring creep and seat fretting because the plain ring has no N2 slots and relies on housing-provided anti-rotation
- rolling-contact fatigue spalling after the rated L10 life is exceeded
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- The inner ring is two-piece: handle both halves together, mount square, and do not separate the split ring unless the fitting procedure requires it.
- Provide a minimum axial load (spring preload is common) so the balls stay correctly seated at speed and light-load conditions; otherwise they skid.
- Run the QJ as a thrust bearing with radial clearance in the housing, paired with a separate radial bearing; the QJ outer ring must not be radially clamped.
- Anti-rotation is NOT built into QJ-210-MA: without N2 slots the housing must provide a dog, keyed cover or other positive stop, since the outer ring runs radially loose by design.
- The MA brass cage of QJ-210-MA is outer-ring-centred: its guide land needs an uninterrupted oil film, so check lubricant reach when the bearing is used purely as a thrust location.
- Catalogue ratings are SKF PUB BU/P1 17000 figures for QJ 210 MA as the qj plain execution; the other order numbers of the QJ 210 size are different products and may carry different ratings — always quote the full designation when purchasing.
Frequently asked questions
What are the dimensions and catalogue data of QJ-210-MA?
QJ 210 MA measures 50 mm bore × 90 mm OD × 20 mm width (1.969 × 3.543 × 0.787 in), mass about 590 g. SKF 17000 ratings: C 65.5 kN, C0 61 kN, Pu 2.6 kN, SKF publishes only the 13,000 r/min limiting speed for this execution.
What does the MA suffix mean?
QJ identifies a four-point contact ball bearing with a two-piece inner ring: the gothic-arch raceways seat each ball at four points, giving axial location in both directions while a paired radial bearing carries the radial load. machined brass cage, outer-ring-centred (suffix MA), which guides on the outer ring rather than on the balls.
What are the N2 locating slots for?
The two slots, 180° apart in one outer-ring side face, engage housing dogs or pins to prevent the radially loose outer ring from creeping and fretting its seat. The non-N2 execution relies on other anti-rotation measures.
What minimum axial load does QJ-210-MA require?
Like angular-contact bearings the QJ needs a minimum axial load to keep the balls seated — spring preload against the outer ring is typical — and the load ratio Fa/Fr ≥ 1,27 keeps contact on one inner-ring raceway and the opposite outer-ring side.
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.