QJ322 bearing: complete specifications & equivalents
The QJ322 is a ISO 15 radial bearing sized 110 x 240 x 50 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 110 mm |
| Outer diameter D | 240 mm |
| Width B | 50 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 340 kN |
| Basic static load rating C0 | 680 kN |
| Fatigue load limit Pu | 22.1 kN |
| Limiting speed (mechanical) | 2300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 12000 g |
| Manufacturer designation | NTN QJ322 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & QJ300-series range
| Bore d | 4.331 in |
|---|---|
| Outer diameter D | 9.449 in |
| Width B | 1.969 in |
| ISO bore code | 22 |
| Radial section height (D−d)/2 | 65 mm |
| Smallest bore in QJ300-series | 17 mm |
| Largest outer diameter in QJ300-series | 400 mm |
| Width range across QJ300-series | 14–78 mm |
| Bore position in QJ300-series (smallest first) | 20 of 28 |
| Bore above smallest QJ300-series size | 93 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| QJ322 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 QJ322 model number is decoded
From the heavy-duty QJ300 four-point family, QJ322 measures 110 mm across the bore, 240 mm over the outer ring and 50 mm across the faces. Reading the code: QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), the last two digits 22 give the bore by the standard code table (110 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. For a 110 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. Heat-mounting to 80-90 deg C is the clean route onto a 110 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it.
Typical equipment & failure modes
Common applications
- rolling-mill and metalworking drive shafts
- large pump, fan and compressor rotor shafts
- crane and hoist gearbox shafts
- paper-machine roll and calendar drives
Known failure patterns
- false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch
- loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow
- pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed
- lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated
- edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face
Selection pitfalls — read before you substitute
- Bearings of 110 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.
- The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.
- Grease rated for deep-groove motor duty is not automatically right at 2,300 r/min with preload; check the grease speed factor against the catalogue figure.
- Never use a four-point or double-row bearing as a like-for-like swap for a single QJ322 without re-checking axial float, heat and housing width — the kinematics differ.
- The 2,300 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.
- The 340/680 kN ratings and 22.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ322; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN QJ322?
QJ322 is a four-point contact ball bearing to ISO 15: 110 mm bore, 240 mm outside diameter, 50 mm width (4.331 x 9.449 x 1.969 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 340 kN, C0 680 kN and a 22.1 kN fatigue load limit Pu; the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min; mass about 12000 g.
How is the QJ322 designation structured?
QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 22 give the bore by the standard code table (110 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 240 mm OD and 50 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does QJ322 support?
QJ322 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member.
What lubrication speeds does NTN print for QJ322?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit.
What should be checked before substituting another make for QJ322?
The 110/240/50 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 340 kN / C0 680 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.