7209B bearing: complete specifications & equivalents
The 7209B 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 | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 40 kN |
| Basic static load rating C0 | 26.2 kN |
| Fatigue load limit Pu | 2.04 kN |
| Limiting speed (mechanical) | 7400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 410 g |
| Manufacturer designation | NTN 7209B |
| 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 | 1.772 in |
|---|---|
| Outer diameter D | 3.346 in |
| Width B | 0.748 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) | 10 of 36 |
| Bore above smallest 7200-series size | 35 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 7209B model number is decoded
NTN 7209B belongs to the medium-duty 7200 single-row family: the catalogue boundary dimensions read 45 / 85 / 19 mm (bore / OD / width). Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 09 encodes the 45 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). At roughly 20.0 mm of radial section, the catalogue still quotes 40 kN dynamic capacity for the 45 mm bore. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated.
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
- 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
- edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face
- 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
- 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 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.
- Do not pair two random 7209B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.
- The 7,400 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.
- 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.
- The 40/26.2 kN ratings and 2.04 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7209B; 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 7209B?
7209B is a single-row angular 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 40 kN, C0 26.2 kN and a 2.04 kN fatigue load limit Pu; the grease limiting speed is 7,400 r/min and the oil rating 9,900 r/min; mass about 410 g.
How is the 7209B designation structured?
72 is the single-row dimension series (medium-duty 7200 single-row family); 09 encodes the 45 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 85 mm OD and 19 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 7209B support?
One 7209B 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 7209B?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,400 r/min and the oil rating 9,900 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 7209B?
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 40 kN / C0 26.2 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.