29280 bearing: complete specifications & equivalents
The 29280 is a ISO 104 radial bearing sized 400 x 540 x 85 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 400 mm |
| Outer diameter D | 540 mm |
| Width B | 85 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1610 kN |
| Basic static load rating C0 | 8000 kN |
| Fatigue load limit Pu | 695 kN |
| Reference speed (thermal) | 700 rpm |
| Limiting speed (mechanical) | 1100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 55500 g |
| Manufacturer designation | 29280 |
| Standard | ISO 104 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 13.1 spherical roller thrust bearings |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 13.1 spherical roller thrust bearings) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 13.1 spherical roller thrust bearings); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & 29200-series range
| Bore d | 15.748 in |
|---|---|
| Outer diameter D | 21.26 in |
| Width B | 3.346 in |
| ISO bore code | 80 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in 29200-series | 150 mm |
| Largest outer diameter in 29200-series | 1060 mm |
| Width range across 29200-series | 39–155 mm |
| Bore position in 29200-series (smallest first) | 13 of 23 |
| Bore above smallest 29200-series size | 250 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 29280 model number is decoded
The high-speed 292 series bearing 29280 carries 1610 kN of thrust on barrel rollers whose contact angle also tolerates radial force up to a fraction of the applied thrust — the standard heavy-duty thrust bearing for 400 mm shafts. The designation 29280 separates into 292 (series), 80 (400 mm bore) and no suffix (earlier standard design); washers are separable for individual mounting. The contact geometry also accepts simultaneous radial load up to roughly 55 % of the simultaneous axial force; beyond that mix, add a separate radial bearing to the arrangement. Static safety matters for shock duty: compare peak axial force against C0 8000 kN with the application's static factor, since crane hooks and screw positions see their worst load at zero or low speed. Mounting: fit the shaft washer tight on the 400 mm seat, seat the sphered housing washer on its matching (often separately supplied) seating washer, and check the assembly swivels freely before applying the 1610 kN working load.
Typical equipment & failure modes
Common applications
- marine shaft and rudder-style thrust positions with seat deflection
- paper machine calender and refiner discs with combined axial and radial force
- crane hook assemblies where the hook block turns under full load
- injection moulding machine and extruder screw thrust positions
Known failure patterns
- cage wear from rollers being dragged through unloaded zones under fluctuating thrust
- washer back-face fretting where the seat is too narrow to support the full ring face
- grease churning and overheating when a high-speed thrust position is over-packed
- rolling-contact fatigue spalling after the catalogue L10 life is exhausted
- roller skidding and raceway glazing once the thrust falls below the catalogue minimum axial load (factor A)
Selection pitfalls — read before you substitute
- Above 300 mm bore the minimum load is large (A 6.1 here): design the preload or lift sequence explicitly — an unloaded slow rotation glazes the 540 mm washer track.
- the 700 r/min reference speed is the thermal criterion under load, the 1,100 r/min limiting speed is the mechanical ceiling; large 292 bearings are normally run well below it with oil cooling.
- Radial force beyond the permitted fraction of simultaneous thrust (about 0.55·F_a) overloads one side of the barrel-roller set — add a radial bearing instead of leaning on 29280.
- The 1610/8000 kN figures assume the matching sphered seating washer is fitted where the catalogue calls for it; a flat housing seat removes the self-aligning function.
- Minimum load factor A 6.1 dominates commissioning: start the oil flow and preload before rotation, especially on 292 bearings where an unloaded cold start smears the rollers.
- The 1610/8000 kN ratings and 55500 g mass are SKF catalogue values transcribed from ch. 13.1 of PUB BU/P1 17000 (PDF table page 928); mounting data — the minimum axial load factor A — appears in the running text because the structured record carries the boundary envelope only.
Frequently asked questions
How is the 29280 designation read?
292 is the dimension series (high-speed 292 series) and 80 the 400 mm bore (code 80 × 5); no suffix is the cage execution (steel cage of the earlier standard design). The sphered housing washer provides self-alignment.
Why is the minimum axial load (A 6.1) so important?
Spherical roller thrust bearings skid and smear immediately when run unloaded — on large sizes factor A 6.1 corresponds to a substantial force. Springs, oil lift or the rotor/load weight must be applied before rotation, including cold test runs.
Can the 29280 also carry radial load?
Yes, up to roughly 55 % of the simultaneous axial force, thanks to the steep contact angle of the barrel rollers. Beyond that mix, specify a separate radial bearing; the primary duty remains one-direction thrust.
How is a 29280 mounted?
Tight shaft washer on the 400 mm seat, sphered housing washer on its matching seating washer, induction heating for large sizes, oil at the catalogue level before start, and the factor-A 6.1 preload verified at commissioning.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 13.1 spherical roller thrust bearings on 2026-09-27. Read our editorial & correction policy.