QJ-232-N2MA bearing: complete specifications & equivalents

The QJ-232-N2MA is a ISO 15 radial bearing sized 160 x 290 x 48 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.

Bearing dimension schematic Front view shows outer diameter D and bore d; side section shows width B. D = 290 mm d = 160 B = 48 mm side section front view
Principal dimensions: bore d 160 mm, outer diameter D 290 mm, width B 48 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand SKF
Bore diameter d 160 mm
Outer diameter D 290 mm
Width B 48 mm
Material GCr15
Seal / shield open
Internal clearance CN
Tolerance class P0
Cage brass
Basic dynamic load rating C 450 kN
Basic static load rating C0 670 kN
Fatigue load limit Pu 19 kN
Limiting speed (mechanical) 3800 rpm
Operating temperature -40 to +120 °C
Mass 15500 g
Manufacturer designation QJ 232 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 6.299 in
Outer diameter D 11.417 in
Width B 1.89 in
ISO bore code —
Radial section height (D−d)/2 65 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) 25 of 29
Bore above smallest QJ200-series size 145 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
7232-BCBM SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 160×290×48 mm envelope, but catalogue C/C0 differ between executions (450/670 kN vs 255/300 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-232-N2MA model number is decoded

QJ 232 N2MA is SKF's 160 mm-bore QJ four-point contact ball bearing of the QJ200 series, 160×290×48 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 160×290×48 mm (6.299×11.417×1.89 in), 65.0 mm radial section height, C 450 kN, C0 670 kN, Pu 19 kN.SKF publishes only the 3,800 r/min limiting speed for this execution, catalogue mass 15500 g. Speed planning distinguishes the two published ceilings mechanically: the cage and balls tolerate 3,800 r/min and no separate thermal reference is published; at dm ≈ 225.0 mm the corresponding dn is approximately 855k mm·r/min. Sizing arithmetic on the 160 mm bore: 450 kN C divided by the 65.0 mm radial section height gives 6.9 kN per section millimetre; the 15500 g mass and 4 % Pu/C share frame the light-load floor for the adjusted-life check. Bore-to-OD planning: OD 290 over bore 160 is a 1.81× step for this size, and the 48 mm width gives a bore/width ratio of 3.33; use these ratios when housing space around the 160 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

  • marine transmission thrust positions
  • rolling-mill adjustment mechanisms
  • offshore winch and swivel drives

Known failure patterns

  • axial over-travel when the outer ring is clamped instead of left with radial clearance and a small end-play gap
  • two-piece inner-ring separation damage if the split ring is pressed or heated unevenly during mounting
  • locating-slot root fretting or dog wear when only one N2 notch carries the anti-rotation torque
  • mounting score marks when the bearing is cocked over a burr or keyway
  • mounting score marks when the bearing is cocked over a burr or keyway

Selection pitfalls — read before you substitute

  • Provide a minimum axial load (spring preload is common) so the balls stay correctly seated at speed and light-load conditions; otherwise they skid.
  • Engage the N2 slots with housing dogs at assembly — a radially loose outer ring without positive anti-rotation creeps its seat
  • Apply the Fa/Fr ≥ 1,27 condition: at lower ratios the balls contact both sides of a raceway, increasing friction and shortening life — the paired radial bearing should carry the radial share.
  • Anti-rotation is built into QJ-232-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-232-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 232 N2MA as the qj slotted execution; the other order numbers of the QJ 232 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-232-N2MA?

QJ 232 N2MA measures 160 mm bore × 290 mm OD × 48 mm width (6.299 × 11.417 × 1.89 in), mass about 15500 g. SKF 17000 ratings: C 450 kN, C0 670 kN, Pu 19 kN, SKF publishes only the 3,800 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 minimum axial load does QJ-232-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.

How is a QJ four-point bearing mounted?

As a thrust/locating bearing with radial clearance in the housing, paired with a separate radial bearing (commonly a cylindrical roller bearing): the QJ locates the shaft axially in both directions, the radial bearing carries radial load. Keep the outer ring unclamped with a small end-play gap; N2 slot executions use dogs to stop the outer ring turning.

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.