7315B bearing: complete specifications & equivalents
The 7315B is a ISO 15 radial bearing sized 75 x 160 x 37 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 75 mm |
| Outer diameter D | 160 mm |
| Width B | 37 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 138 kN |
| Basic static load rating C0 | 97.5 kN |
| Fatigue load limit Pu | 7 kN |
| Limiting speed (mechanical) | 4100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3130 g |
| Manufacturer designation | NTN 7315B |
| 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 | 2.953 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.457 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 42.5 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) | 16 of 32 |
| Bore above smallest 7300-series size | 65 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 7315B | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 7315B model number is decoded
At 75 x 160 x 37 mm, NTN 7315B sits in the heavy-duty 7300 single-row family of the angular-contact programme. Decoding 7315B: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 15 encodes the 75 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 static margin, C0 97.5 kN versus C 138 kN, is what supports slow oscillating duty and shock without immediate brinelling. 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. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 75 mm bore give the working limits.
Typical equipment & failure modes
Common applications
- mining conveyor head-shaft positions
- marine auxiliary and winch gearbox shafts
- rolling-mill and metalworking drive shafts
- large pump, fan and compressor rotor 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
- thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear
- 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
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
Selection pitfalls — read before you substitute
- Bearings of 75 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.
- 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.
- Grease rated for deep-groove motor duty is not automatically right at 4,100 r/min with preload; check the grease speed factor against the catalogue figure.
- A single-row angular contact left loose on the shaft to "help assembly" will fret the seat: the contact angle keeps driving the ring axially under load.
- Do not pair two random 7315B 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 138/97.5 kN ratings and 7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7315B; 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 7315B?
7315B is a single-row angular contact ball bearing to ISO 15: 75 mm bore, 160 mm outside diameter, 37 mm width (2.953 x 6.299 x 1.457 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 138 kN, C0 97.5 kN and a 7 kN fatigue load limit Pu; the grease limiting speed is 4,100 r/min and the oil rating 5,400 r/min; mass about 3130 g.
How is the 7315B designation structured?
73 is the single-row dimension series (heavy-duty 7300 single-row family); 15 encodes the 75 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 160 mm OD and 37 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 7315B support?
One 7315B 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 7315B?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,100 r/min and the oil rating 5,400 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 7315B?
The 75/160/37 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 138 kN / C0 97.5 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.