7210B bearing: complete specifications & equivalents
The 7210B 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 | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 41.5 kN |
| Basic static load rating C0 | 28.6 kN |
| Fatigue load limit Pu | 2.16 kN |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 466 g |
| Manufacturer designation | NTN 7210B |
| 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 & 7200-series range
| Bore d | 1.969 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 0.787 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in 7200-series | 10 mm |
| Largest outer diameter in 7200-series | 540 mm |
| Width range across 7200-series | 9–85 mm |
| Bore position in 7200-series (smallest first) | 11 of 36 |
| Bore above smallest 7200-series size | 40 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 7210B model number is decoded
7210B is the 50 mm bore member of NTN's medium-duty 7200 single-row family, with a 90 mm outside diameter and 20 mm section width. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 10 encodes the 50 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). With C 41.5 kN and C0 28.6 kN, each mm of bore carries about 0.83 kN of dynamic rating. Size selection is usually finished by checking that the C0 of 28.6 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Heat-mounting to 80-90 deg C is the clean route onto a 50 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it.
Typical equipment & failure modes
Common applications
- industrial pump and blower impeller shafts
- gearbox input shafts under helical-gear thrust
- electric motor shafts with axial locating duty
- conveyor drive and tension-drum 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
- 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
- contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue
- 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 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.
- The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.
- Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.
- A 7210B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.
- 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 41.5/28.6 kN ratings and 2.16 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7210B; 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 7210B?
7210B is a single-row angular 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 41.5 kN, C0 28.6 kN and a 2.16 kN fatigue load limit Pu; the grease limiting speed is 6,700 r/min and the oil rating 9,000 r/min; mass about 466 g.
How is the 7210B designation structured?
72 is the single-row dimension series (medium-duty 7200 single-row family); 10 encodes the 50 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 90 mm OD and 20 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 7210B support?
One 7210B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact.
What lubrication speeds does NTN print for 7210B?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,700 r/min and the oil rating 9,000 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 7210B?
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 41.5 kN / C0 28.6 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.