QJ210 bearing: complete specifications & equivalents
The QJ210 is a ISO 15 radial bearing sized 50 x 90 x 20 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 50 mm |
| Outer diameter D | 90 mm |
| Width B | 20 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 57.5 kN |
| Basic static load rating C0 | 89 kN |
| Fatigue load limit Pu | 3.8 kN |
| Limiting speed (mechanical) | 5600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 603 g |
| Manufacturer designation | NTN QJ210 |
| 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 | 1.969 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 0.787 in |
| ISO bore code | 10 |
| 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) | 8 of 29 |
| Bore above smallest QJ200-series size | 35 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the QJ210 model number is decoded
From the medium-duty QJ200 four-point family, QJ210 measures 50 mm across the bore, 90 mm over the outer ring and 20 mm across the faces. Decoding QJ210: QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), with the last two digits 10 give the bore by the standard code table (50 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. On speed, the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 50 mm bore give the working limits.
Typical equipment & failure modes
Common applications
- electric motor shafts with axial locating duty
- conveyor drive and tension-drum shafts
- agricultural gearbox and PTO shaft supports
- printing-press cylinder and folder shafts
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
- machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
Selection pitfalls — read before you substitute
- In this size class the common miss is lubrication interval, not fit — a 50 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.
- Grease rated for deep-groove motor duty is not automatically right at 5,600 r/min with preload; check the grease speed factor against the catalogue figure.
- On a 50 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 C0 of 89 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.
- The 57.5/89 kN ratings and 3.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ210; 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 QJ210?
QJ210 is a four-point contact ball bearing to ISO 15: 50 mm bore, 90 mm outside diameter, 20 mm width (1.969 x 3.543 x 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 57.5 kN, C0 89 kN and a 3.8 kN fatigue load limit Pu; the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min; mass about 603 g.
How is the QJ210 designation structured?
QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 10 give the bore by the standard code table (50 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 90 mm OD and 20 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does QJ210 support?
QJ210 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 QJ210?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,600 r/min and the oil rating 7,500 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 QJ210?
The 50/90/20 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 57.5 kN / C0 89 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.