QJ209 bearing: complete specifications & equivalents
The QJ209 is a ISO 15 radial bearing sized 45 x 85 x 19 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 45 mm |
| Outer diameter D | 85 mm |
| Width B | 19 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 55 kN |
| Basic static load rating C0 | 81 kN |
| Fatigue load limit Pu | 3.5 kN |
| Limiting speed (mechanical) | 6200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 520 g |
| Manufacturer designation | NTN QJ209 |
| 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 & QJ200-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 3.346 in |
| Width B | 0.748 in |
| ISO bore code | 09 |
| 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) | 7 of 29 |
| Bore above smallest QJ200-series size | 30 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the QJ209 model number is decoded
QJ209 is the 45 mm bore member of NTN's medium-duty QJ200 four-point family, with a 85 mm outside diameter and 19 mm section width. The designation breaks down as QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 09 give the bore by the standard code table (45 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. Against a deep-groove bearing of the same 45 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Grease quantity matters as much as grade at 6,200 r/min: fill about a third of the free space and let the bearing purge on first run.
Typical equipment & failure modes
Common applications
- printing-press cylinder and folder shafts
- machine-tool spindle cartridges and driven tooling
- industrial pump and blower impeller shafts
- gearbox input shafts under helical-gear thrust
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
- resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
- lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated
Selection pitfalls — read before you substitute
- In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.
- 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.
- Never use a four-point or double-row bearing as a like-for-like swap for a single QJ209 without re-checking axial float, heat and housing width — the kinematics differ.
- Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.
- The 6,200 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 55/81 kN ratings and 3.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ209; 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 QJ209?
QJ209 is a four-point contact ball bearing to ISO 15: 45 mm bore, 85 mm outside diameter, 19 mm width (1.772 x 3.346 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 55 kN, C0 81 kN and a 3.5 kN fatigue load limit Pu; the grease limiting speed is 6,200 r/min and the oil rating 8,200 r/min; mass about 520 g.
How is the QJ209 designation structured?
QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 09 give the bore by the standard code table (45 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 85 mm OD and 19 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does QJ209 support?
QJ209 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 QJ209?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,200 r/min and the oil rating 8,200 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 QJ209?
The 45/85/19 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 55 kN / C0 81 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.