7334 bearing: complete specifications & equivalents
The 7334 is a ISO 15 radial bearing sized 170 x 360 x 72 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 170 mm |
| Outer diameter D | 360 mm |
| Width B | 72 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 430 kN |
| Basic static load rating C0 | 485 kN |
| Fatigue load limit Pu | 23.3 kN |
| Limiting speed (mechanical) | 2000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 35300 g |
| Manufacturer designation | NTN 7334 |
| 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 | 6.693 in |
|---|---|
| Outer diameter D | 14.173 in |
| Width B | 2.835 in |
| ISO bore code | 34 |
| Radial section height (D−d)/2 | 95 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) | 29 of 32 |
| Bore above smallest 7300-series size | 160 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 7334-BCBM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 170×360×72 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 7334 model number is decoded
7334 is the 170 mm bore member of NTN's heavy-duty 7300 single-row family, with a 360 mm outside diameter and 72 mm section width. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 34 encodes the 170 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 35300 g, which at this 95.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Grease quantity matters as much as grade at 2,000 r/min: fill about a third of the free space and let the bearing purge on first run.
Typical equipment & failure modes
Common applications
- heavy industrial gearbox main shafts
- large fan, blower and turbo-compressor rotors
- rolling-mill backup and drive spindles
- crusher and mill pinion 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
- 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
- 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
- At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 170 mm bore bearing forgives nothing in a poorly machined housing.
- 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.
- 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.
- A 7334 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.
- 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 430/485 kN ratings and 23.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7334; 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 7334?
7334 is a single-row angular contact ball bearing to ISO 15: 170 mm bore, 360 mm outside diameter, 72 mm width (6.693 x 14.173 x 2.835 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 430 kN, C0 485 kN and a 23.3 kN fatigue load limit Pu; the grease limiting speed is 2,000 r/min and the oil rating 2,700 r/min; mass about 35300 g.
How is the 7334 designation structured?
73 is the single-row dimension series (heavy-duty 7300 single-row family); 34 encodes the 170 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 360 mm OD and 72 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 7334 support?
One 7334 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 7334?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,000 r/min and the oil rating 2,700 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 7334?
The 170/360/72 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 430 kN / C0 485 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.