29456 bearing: complete specifications & equivalents
The 29456 is a ISO 104 radial bearing sized 280 x 520 x 145 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 280 mm |
| Outer diameter D | 520 mm |
| Width B | 145 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 3700 kN |
| Basic static load rating C0 | 12400 kN |
| Fatigue load limit Pu | 710 kN |
| Limiting speed (mechanical) | 610 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 140000 g |
| Manufacturer designation | NTN 29456 |
| 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 | 11.024 in |
|---|---|
| Outer diameter D | 20.472 in |
| Width B | 5.709 in |
| ISO bore code | 56 |
| Radial section height (D−d)/2 | 120 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) | 22 of 46 |
| Bore above smallest 29400-series size | 220 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 29456-E | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 280×520×145 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 29456 model number is decoded
From the heavy-section 29400 spherical-thrust family, 29456 measures 280 mm through the shaft washer, 520 mm over the outside and 145 mm in assembled height. NTN builds the number from 294 is the dimension series (heavy-section 29400 spherical-thrust family); 56 encodes the 280 mm bore (bore code x 5). Catalogue mass is about 140 kg for the full washer-and-roller stack. Within the spherical-thrust plan, 292 is the light section and 294 the heavy one; stepping up from a 292 to a 294 at the same bore roughly doubles the C0a class. 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
- rotary kiln and furnace thrust positions
- large vertical mill and crusher main shafts
- heavy stacker/reclaimer and shiploading pivots
- vertical hydro and pump-turbine main thrust blocks
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
- fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact
Selection pitfalls — read before you substitute
- At 280 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 520 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.
- Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29456 was chosen for.
- Shock thrust above C0a 12400 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.
- The 145 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.
- The Ca 3700/C0a 12400 kN ratings and 710 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29456; 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 29456?
29456 is a spherical roller thrust bearing to ISO 104: 280 mm shaft-washer bore, 520 mm outside diameter, 145 mm stack height (11.024 x 20.472 x 5.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 3700 kN, C0a 12400 kN and a 710 kN fatigue load limit Pu; limiting speed 610 r/min with oil lubrication; mass about 140000 g.
How is the 29456 designation structured?
294 is the dimension series (heavy-section 29400 spherical-thrust family); 56 encodes the 280 mm bore (bore code x 5). The 520 mm OD and 145 mm height follow the ISO 104 boundary plan for that series.
Can 29456 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, 610 r/min, for 29456?
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 29456?
The 280/520/145 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 3700 kN / C0a 12400 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.