29340 bearing: complete specifications & equivalents
The 29340 is a ISO 104 radial bearing sized 200 x 340 x 85 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 200 mm |
| Outer diameter D | 340 mm |
| Width B | 85 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 1420 kN |
| Basic static load rating C0 | 4600 kN |
| Fatigue load limit Pu | 330 kN |
| Limiting speed (mechanical) | 980 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 31900 g |
| Manufacturer designation | NTN 29340 |
| Standard | ISO 104 |
| 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 & 29300-series range
| Bore d | 7.874 in |
|---|---|
| Outer diameter D | 13.386 in |
| Width B | 3.346 in |
| ISO bore code | 40 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in 29300-series | 85 mm |
| Largest outer diameter in 29300-series | 1180 mm |
| Width range across 29300-series | 39–230 mm |
| Bore position in 29300-series (smallest first) | 13 of 31 |
| Bore above smallest 29300-series size | 115 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 29340-E | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 200×340×85 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 29340 model number is decoded
NTN 29340 belongs to the medium-section 29300 spherical-thrust family of spherical roller thrust bearings: 200 / 340 / 85 mm (bore / OD / height). Two fields make up the code — 293 is the dimension series (medium-section 29300 spherical-thrust family) and 40 encodes the 200 mm bore (bore code x 5). At 85 mm of height the bearing packs the medium-section capacity into a stack far shorter than a comparable multi-row ball arrangement. Selection starts from the load case: axial must dominate, and any radial share must stay within the catalogue combined-load rule while the bearing self-aligns. The 200 mm shaft washer normally mounts with a tight shaft fit; support the housing washer so it stays free to align on its spherical seat.
Typical equipment & failure modes
Common applications
- vertical hydro and pump-turbine main thrust blocks
- heavy rolling-mill and forging-press thrust seats
- large marine propulsion thrust supports
- crane and excavator main slew bearings duty
Known failure patterns
- edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite
- oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage
- roller skid smearing when axial load fell below the minimum while the shaft was still turning fast
- contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue
- thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation
Selection pitfalls — read before you substitute
- At 200 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.
- The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 200 mm bore.
- Below the minimum axial load the rollers skid; at 980 r/min the Ca of 1420 kN never comes into play before the raceway is smeared.
- Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.
- Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.
- The Ca 1420/C0a 4600 kN ratings and 330 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29340; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 29340?
29340 is a spherical roller thrust bearing to ISO 104: 200 mm shaft-washer bore, 340 mm outside diameter, 85 mm stack height (7.874 x 13.386 x 3.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1420 kN, C0a 4600 kN and a 330 kN fatigue load limit Pu; limiting speed 980 r/min with oil lubrication; mass about 31900 g.
How is the 29340 designation structured?
293 is the dimension series (medium-section 29300 spherical-thrust family); 40 encodes the 200 mm bore (bore code x 5). The 340 mm OD and 85 mm height follow the ISO 104 boundary plan for that series.
Can 29340 handle misalignment and radial load?
Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing.
Why does NTN print only an oil speed, 980 r/min, for 29340?
Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run.
What should be checked before substituting another make for 29340?
The 200/340/85 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1420 kN / C0a 4600 kN, the oil speed rating and the minimum-load requirement 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.