7305-NTN bearing: complete specifications & equivalents
The 7305-NTN is a ISO 15 radial bearing sized 25 x 62 x 17 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 25 mm |
| Outer diameter D | 62 mm |
| Width B | 17 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 29.3 kN |
| Basic static load rating C0 | 15.8 kN |
| Fatigue load limit Pu | 1.24 kN |
| Limiting speed (mechanical) | 13000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 230 g |
| Manufacturer designation | NTN 7305 |
| 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 & 7300-series range
| Bore d | 0.984 in |
|---|---|
| Outer diameter D | 2.441 in |
| Width B | 0.669 in |
| ISO bore code | 05 |
| Radial section height (D−d)/2 | 18.5 mm |
| Smallest bore in 7300-series | 10 mm |
| Largest outer diameter in 7300-series | 420 mm |
| Width range across 7300-series | 11–80 mm |
| Bore position in 7300-series (smallest first) | 6 of 32 |
| Bore above smallest 7300-series size | 15 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 7305 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 7305-ACCBM | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 7305-BE-2RZP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×62×17 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting. |
| 7305-BECBM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 7305-BECBP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 7305-BECBPH | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 7305-BECBY | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 7305-BEP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 7305-BEY | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 7305-NTN model number is decoded
7305 is the 25 mm bore member of NTN's heavy-duty 7300 single-row family, with a 62 mm outside diameter and 17 mm section width. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 05 encodes the 25 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 230 g, which at this 18.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Against a deep-groove bearing of the same 25 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away.
Typical equipment & failure modes
Common applications
- servo and stepper motor shafts with axial preload
- bicycle and motorcycle wheel and steering positions
- small gearbox pinion shafts with helical gears
- precision instrument and encoder support 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
- pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed
- 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
- At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.
- The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.
- On a 25 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.
- On a 25 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.
- 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.
- The 29.3/15.8 kN ratings and 1.24 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7305; 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 7305?
7305 is a single-row angular contact ball bearing to ISO 15: 25 mm bore, 62 mm outside diameter, 17 mm width (0.984 x 2.441 x 0.669 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 29.3 kN, C0 15.8 kN and a 1.24 kN fatigue load limit Pu; the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min; mass about 230 g.
How is the 7305 designation structured?
73 is the single-row dimension series (heavy-duty 7300 single-row family); 05 encodes the 25 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 62 mm OD and 17 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 7305 support?
One 7305 alone takes thrust in one direction only, along its 30 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 7305?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 13,000 r/min and the oil rating 17,000 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 7305?
The 25/62/17 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 29.3 kN / C0 15.8 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.