QJ211 bearing: complete specifications & equivalents
The QJ211 is a ISO 15 radial bearing sized 55 x 100 x 21 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 55 mm |
| Outer diameter D | 100 mm |
| Width B | 21 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 71 kN |
| Basic static load rating C0 | 112 kN |
| Fatigue load limit Pu | 4.8 kN |
| Limiting speed (mechanical) | 5100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 780 g |
| Manufacturer designation | NTN QJ211 |
| 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 | 2.165 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 0.827 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 22.5 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) | 9 of 29 |
| Bore above smallest QJ200-series size | 40 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the QJ211 model number is decoded
QJ211 is an NTN four-point contact ball bearing: medium-duty QJ200 four-point family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 55 x 100 x 21 mm. NTN builds the number from QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), then the last two digits 11 give the bore by the standard code table (55 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. With C 71 kN and C0 112 kN, each mm of bore carries about 1.29 kN of dynamic rating. Choose the medium-duty QJ200 four-point family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Heat-mounting to 80-90 deg C is the clean route onto a 55 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it.
Typical equipment & failure modes
Common applications
- agricultural gearbox and PTO shaft supports
- printing-press cylinder and folder shafts
- machine-tool spindle cartridges and driven tooling
- industrial pump and blower impeller shafts
Known failure patterns
- impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle
- thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear
- pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed
- edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face
- flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share
Selection pitfalls — read before you substitute
- In this size class the common miss is lubrication interval, not fit — a 55 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.
- If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.
- A single-row angular contact left loose on the shaft to "help assembly" will fret the seat: the contact angle keeps driving the ring axially under load.
- On a 55 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.
- The 71/112 kN ratings and 4.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ211; 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 QJ211?
QJ211 is a four-point contact ball bearing to ISO 15: 55 mm bore, 100 mm outside diameter, 21 mm width (2.165 x 3.937 x 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 71 kN, C0 112 kN and a 4.8 kN fatigue load limit Pu; the grease limiting speed is 5,100 r/min and the oil rating 6,800 r/min; mass about 780 g.
How is the QJ211 designation structured?
QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 11 give the bore by the standard code table (55 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 100 mm OD and 21 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does QJ211 support?
QJ211 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 QJ211?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,100 r/min and the oil rating 6,800 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 QJ211?
The 55/100/21 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 71 kN / C0 112 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.