QJ-226-N2MA bearing: complete specifications & equivalents
The QJ-226-N2MA is a ISO 15 radial bearing sized 130 x 230 x 40 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 130 mm |
| Outer diameter D | 230 mm |
| Width B | 40 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 310 kN |
| Basic static load rating C0 | 400 kN |
| Fatigue load limit Pu | 12.7 kN |
| Limiting speed (mechanical) | 4800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7750 g |
| Manufacturer designation | QJ 226 N2MA |
| 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 | 5.118 in |
|---|---|
| Outer diameter D | 9.055 in |
| Width B | 1.575 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 50 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) | 22 of 29 |
| Bore above smallest QJ200-series size | 115 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 7226-BCBM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 130×230×40 mm envelope, but catalogue C/C0 differ between executions (310/400 kN vs 186/193 kN) — boundary dimensions match, not a load-rating equivalent. |
| 7226-BM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 130×230×40 mm envelope, but catalogue C/C0 differ between executions (310/400 kN vs 186/193 kN) — boundary dimensions 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-226-N2MA model number is decoded
QJ 226 N2MA is SKF's 130 mm-bore QJ four-point contact ball bearing of the QJ200 series, 130×230×40 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. N2 marks two locating slots, 180° apart, in one outer-ring side face: pins or dogs engage the slots to stop the outer ring turning in its radially-clear housing bore. machined brass cage, outer-ring-centred (suffix MA), which guides on the outer ring rather than on the balls. Envelope 130×230×40 mm (5.118×9.055×1.575 in), 50.0 mm radial section height, C 310 kN, C0 400 kN, Pu 12.7 kN.SKF publishes only the 4,800 r/min limiting speed for this execution, catalogue mass 7750 g. Load balance: C0 400 kN against C 310 kN gives a 1.29 ratio, typical of a four-point thrust-oriented design; Pu 12.7 kN enters the SKF adjusted-life equation rather than the basic rating life. Mass and section check: 7750 g inside the 130×230×40 mm outline leaves a 50.0 mm radial section, and the 400 kN static rating is 1.29× the dynamic rating — plan static safety and minimum load against those numbers rather than against sister executions. Bore-to-OD planning: OD 230 over bore 130 is a 1.77× step for this size, and the 40 mm width gives a bore/width ratio of 3.25; use these ratios when housing space around the 130 mm shaft is the first constraint. Locating-slot execution: the two N2 notches are milled into one outer-ring side face exactly 180 degrees apart and engaged by housing dogs or headed pins during assembly; verify dog engagement by hand before the cover goes on, deburr the slot edges after any housing rework, and re-inspect the slot roots for fretting marks at each overhaul because a dog that rides only one slot lets the outer ring walk. The slots identify this order number unmistakably: the plain MA/PHAS execution of the same bore has no notches and must be secured differently.
Typical equipment & failure modes
Common applications
- large gearbox thrust locations paired with cylindrical roller radial bearings
- marine transmission thrust positions
- rolling-mill adjustment mechanisms
Known failure patterns
- two-piece inner-ring separation damage if the split ring is pressed or heated unevenly during mounting
- false brinelling while the shaft stands with pure radial load and no minimum axial load
- locating-slot root fretting or dog wear when only one N2 notch carries the anti-rotation torque
- electrical pitting on VFD-driven shafts without grounding protection
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- 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.
- 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.
- Keep a small axial gap between the outer ring and the cover flange so it can accommodate thermal movement; never clamp the outer ring solid.
- Anti-rotation is built into QJ-226-N2MA: check the two N2 slot faces and the engaging housing dogs at every refit, and never rely on cover friction to stop the radially loose outer ring.
- The MA brass cage of QJ-226-N2MA 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 226 N2MA as the qj slotted execution; the other order numbers of the QJ 226 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-226-N2MA?
QJ 226 N2MA measures 130 mm bore × 230 mm OD × 40 mm width (5.118 × 9.055 × 1.575 in), mass about 7750 g. SKF 17000 ratings: C 310 kN, C0 400 kN, Pu 12.7 kN, SKF publishes only the 4,800 r/min limiting speed for this execution.
What does the N2MA 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. N2 marks two locating slots, 180° apart, in one outer-ring side face: pins or dogs engage the slots to stop the outer ring turning in its radially-clear housing bore. 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-226-N2MA 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.