29440 bearing: complete specifications & equivalents
The 29440 is a ISO 104 radial bearing sized 200 x 400 x 122 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 | 400 mm |
| Width B | 122 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 2490 kN |
| Basic static load rating C0 | 7650 kN |
| Fatigue load limit Pu | 465 kN |
| Limiting speed (mechanical) | 790 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 73300 g |
| Manufacturer designation | NTN 29440 |
| 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 | 7.874 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 4.803 in |
| ISO bore code | 40 |
| Radial section height (D−d)/2 | 100 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) | 18 of 46 |
| Bore above smallest 29400-series size | 140 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 29440-E | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 200×400×122 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 29440 model number is decoded
At 200 x 400 x 122 mm, NTN 29440 sits in the heavy-section 29400 spherical-thrust family of the spherical-thrust programme. Reading the code: 294 is the dimension series (heavy-section 29400 spherical-thrust family), and 40 encodes the 200 mm bore (bore code x 5). The single printed speed, 790 r/min, is an oil-lubrication figure: the catalogue greases these bearings only for the smallest duties, and this size is rated for oil. The 200/400/122 envelope follows ISO 104, so dimensional interchange holds between makers; osculation, roller profile and ratings do not automatically follow. After filling with oil, rotate slowly and watch torque and temperature; a misrouted oil feed shows up in the first minutes of running.
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
- 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
- cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces
- fretting on the shaft seat after the washer crept under reversing axial shock
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 294 heavy section tops the plan at this bore with the largest 400 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.
- The C0a of 7650 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.
- Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 790 r/min end of the range.
- The Ca 2490/C0a 7650 kN ratings and 465 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29440; 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 29440?
29440 is a spherical roller thrust bearing to ISO 104: 200 mm shaft-washer bore, 400 mm outside diameter, 122 mm stack height (7.874 x 15.748 x 4.803 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 2490 kN, C0a 7650 kN and a 465 kN fatigue load limit Pu; limiting speed 790 r/min with oil lubrication; mass about 73300 g.
How is the 29440 designation structured?
294 is the dimension series (heavy-section 29400 spherical-thrust family); 40 encodes the 200 mm bore (bore code x 5). The 400 mm OD and 122 mm height follow the ISO 104 boundary plan for that series.
Can 29440 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, 790 r/min, for 29440?
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 29440?
The 200/400/122 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 2490 kN / C0a 7650 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.