29426 bearing: complete specifications & equivalents
The 29426 is a ISO 104 radial bearing sized 130 x 270 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 | 130 mm |
| Outer diameter D | 270 mm |
| Width B | 85 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 1200 kN |
| Basic static load rating C0 | 3550 kN |
| Fatigue load limit Pu | 232 kN |
| Limiting speed (mechanical) | 1200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 23700 g |
| Manufacturer designation | NTN 29426 |
| 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 | 5.118 in |
|---|---|
| Outer diameter D | 10.63 in |
| Width B | 3.346 in |
| ISO bore code | 26 |
| Radial section height (D−d)/2 | 70 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) | 11 of 46 |
| Bore above smallest 29400-series size | 70 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 29426-E | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 130×270×85 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 29426 model number is decoded
At 130 x 270 x 85 mm, NTN 29426 sits in the heavy-section 29400 spherical-thrust family of the spherical-thrust programme. Decoding 29426: 294 is the dimension series (heavy-section 29400 spherical-thrust family), with 26 encodes the 130 mm bore (bore code x 5). The static/dynamic ratio of 2.96 tells the story of a roller raceway: enormous reserve for slow, shocked or oscillating thrust. Choose the heavy-section 29400 spherical-thrust family when heavy thrust meets misalignment: vertical turbines, mills and slew pivots are the classic homes. On vertical shafts, confirm the minimum axial load from the rotor weight plus any spring preload before the first run at speed.
Typical equipment & failure modes
Common applications
- heavy rolling-mill and forging-press thrust seats
- large marine propulsion thrust supports
- crane and excavator main slew bearings duty
- rotary kiln and furnace thrust positions
Known failure patterns
- cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue
- roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing
- roller skid smearing when axial load fell below the minimum while the shaft was still turning fast
- thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation
- cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces
Selection pitfalls — read before you substitute
- At 130 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 270 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.
- Shock thrust above C0a 3550 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.
- Oil is not optional at this rating: the 1,200 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.
- 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 1200/C0a 3550 kN ratings and 232 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29426; 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 29426?
29426 is a spherical roller thrust bearing to ISO 104: 130 mm shaft-washer bore, 270 mm outside diameter, 85 mm stack height (5.118 x 10.63 x 3.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1200 kN, C0a 3550 kN and a 232 kN fatigue load limit Pu; limiting speed 1,200 r/min with oil lubrication; mass about 23700 g.
How is the 29426 designation structured?
294 is the dimension series (heavy-section 29400 spherical-thrust family); 26 encodes the 130 mm bore (bore code x 5). The 270 mm OD and 85 mm height follow the ISO 104 boundary plan for that series.
Can 29426 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, 1,200 r/min, for 29426?
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 29426?
The 130/270/85 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1200 kN / C0a 3550 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.