29434 bearing: complete specifications & equivalents
The 29434 is a ISO 104 radial bearing sized 170 x 340 x 103 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 | 340 mm |
| Width B | 103 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 1840 kN |
| Basic static load rating C0 | 5750 kN |
| Fatigue load limit Pu | 345 kN |
| Limiting speed (mechanical) | 940 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 45000 g |
| Manufacturer designation | NTN 29434 |
| 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 & 29400-series range
| Bore d | 6.693 in |
|---|---|
| Outer diameter D | 13.386 in |
| Width B | 4.055 in |
| ISO bore code | 34 |
| Radial section height (D−d)/2 | 85 mm |
| Smallest bore in 29400-series | 60 mm |
| Largest outer diameter in 29400-series | 1770 mm |
| Width range across 29400-series | 42–426 mm |
| Bore position in 29400-series (smallest first) | 15 of 46 |
| Bore above smallest 29400-series size | 110 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 29434-E | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 170×340×103 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 29434 model number is decoded
29434 is the 170 mm member of NTN's heavy-section 29400 spherical-thrust family: 340 mm over the housing washer, 103 mm tall. Decoding 29434: 294 is the dimension series (heavy-section 29400 spherical-thrust family), with 34 encodes the 170 mm bore (bore code x 5). The static/dynamic ratio of 3.13 tells the story of a roller raceway: enormous reserve for slow, shocked or oscillating thrust. The 170/340/103 envelope follows ISO 104, so dimensional interchange holds between makers; osculation, roller profile and ratings do not automatically follow. Check face runout of the support surfaces before assembly: the self-aligning feature absorbs steady misalignment, not a rocking seat.
Typical equipment & failure modes
Common applications
- large vertical mill and crusher main shafts
- heavy stacker/reclaimer and shiploading pivots
- vertical hydro and pump-turbine main thrust blocks
- heavy rolling-mill and forging-press thrust seats
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
- flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates
- cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces
- cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces
Selection pitfalls — read before you substitute
- At 170 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 294 heavy section tops the plan at this bore with the largest 340 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.
- Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.
- Shock thrust above C0a 5750 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.
- A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.
- The Ca 1840/C0a 5750 kN ratings and 345 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29434; 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 29434?
29434 is a spherical roller thrust bearing to ISO 104: 170 mm shaft-washer bore, 340 mm outside diameter, 103 mm stack height (6.693 x 13.386 x 4.055 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1840 kN, C0a 5750 kN and a 345 kN fatigue load limit Pu; limiting speed 940 r/min with oil lubrication; mass about 45000 g.
How is the 29434 designation structured?
294 is the dimension series (heavy-section 29400 spherical-thrust family); 34 encodes the 170 mm bore (bore code x 5). The 340 mm OD and 103 mm height follow the ISO 104 boundary plan for that series.
Can 29434 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, 940 r/min, for 29434?
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 29434?
The 170/340/103 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1840 kN / C0a 5750 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.