7230B bearing: complete specifications & equivalents
The 7230B is a ISO 15 radial bearing sized 150 x 270 x 45 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 150 mm |
| Outer diameter D | 270 mm |
| Width B | 45 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 232 kN |
| Basic static load rating C0 | 235 kN |
| Fatigue load limit Pu | 11.9 kN |
| Limiting speed (mechanical) | 2200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 11000 g |
| Manufacturer designation | NTN 7230B |
| 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 | 5.906 in |
|---|---|
| Outer diameter D | 10.63 in |
| Width B | 1.772 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 60 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) | 27 of 36 |
| Bore above smallest 7200-series size | 140 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 7230B model number is decoded
NTN 7230B belongs to the medium-duty 7200 single-row family: the catalogue boundary dimensions read 150 / 270 / 45 mm (bore / OD / width). Decoding 7230B: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 30 encodes the 150 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). On speed, the grease limiting speed is 2,200 r/min and the oil rating 2,900 r/min. 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. A 150 mm shaft typically takes a m6/n6 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted.
Typical equipment & failure modes
Common applications
- steel-plant conveyor and table roll drives
- wind-turbine and heavy-machinery auxiliaries
- heavy industrial gearbox main shafts
- large fan, blower and turbo-compressor rotors
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
- flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
Selection pitfalls — read before you substitute
- At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 150 mm bore bearing forgives nothing in a poorly machined housing.
- 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.
- The C0 of 235 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.
- On a 150 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 235 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.
- The 232/235 kN ratings and 11.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7230B; 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 7230B?
7230B is a single-row angular contact ball bearing to ISO 15: 150 mm bore, 270 mm outside diameter, 45 mm width (5.906 x 10.63 x 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 232 kN, C0 235 kN and a 11.9 kN fatigue load limit Pu; the grease limiting speed is 2,200 r/min and the oil rating 2,900 r/min; mass about 11000 g.
How is the 7230B designation structured?
72 is the single-row dimension series (medium-duty 7200 single-row family); 30 encodes the 150 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 270 mm OD and 45 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 7230B support?
One 7230B 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 7230B?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,200 r/min and the oil rating 2,900 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 7230B?
The 150/270/45 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 232 kN / C0 235 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.