29488-EM bearing: complete specifications & equivalents
The 29488-EM is a ISO 104 radial bearing sized 440 x 780 x 206 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 440 mm |
| Outer diameter D | 780 mm |
| Width B | 206 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 9000 kN |
| Basic static load rating C0 | 32000 kN |
| Fatigue load limit Pu | 2320 kN |
| Reference speed (thermal) | 430 rpm |
| Limiting speed (mechanical) | 750 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 410000 g |
| Manufacturer designation | 29488 EM |
| 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 & 29400-series range
| Bore d | 17.323 in |
|---|---|
| Outer diameter D | 30.709 in |
| Width B | 8.11 in |
| ISO bore code | 88 |
| Radial section height (D−d)/2 | 170 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) | 30 of 46 |
| Bore above smallest 29400-series size | 380 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 29488-EM model number is decoded
The heavy 294 series bearing 29488 EM carries 9000 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 440 mm shafts. The designation 29488 EM separates into 294 (series), 88 (440 mm bore) and EM; washers are separable for individual mounting. The heavy 294 series is typically oil-bath or forced-oil lubricated in the large sizes: the pumping action of the barrel rollers drives oil through the contact, and interrupted oil supply damages the bearing fastest. The 410000 g mass and 206 mm axial height sit between 440 and 780 mm washer diameters; check the seat shoulder spans the full ring face — a narrow shoulder causes washer fretting long before fatigue does. Large 294 bearings go on with induction heating (max 120 °C) and oil injection features on tapered seats; never strike the machined brass EM cage, and fill the oil bath to the catalogue level before first start.
Typical equipment & failure modes
Common applications
- coal mill, cement mill and sugar mill thrust bearings under shock load
- 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
Known failure patterns
- roller skidding and raceway glazing once the thrust falls below the catalogue minimum axial load (factor A)
- shaft-washer creep and fretting corrosion on a soft or undersized shaft shoulder
- abrasive paste forming as dust bypasses the housing seals into the open washer set
- brinelling of washer raceways from impact or mounting force applied through the rolling elements
- smearing at roller-raceway contacts during unloaded startup before the oil film or preload is established
Selection pitfalls — read before you substitute
- Above 300 mm bore the minimum load is large (A 91 here): design the preload or lift sequence explicitly — an unloaded slow rotation glazes the 780 mm washer track.
- Minimum load factor A 91 dominates commissioning: start the oil flow and preload before rotation, especially on 294 bearings where an unloaded cold start smears the rollers.
- The spherical seat tolerates static misalignment, not a continuously rocking housing — a loose sphered seat frets under oscillation and needs the catalogue seat tolerances plus clean, greased contact.
- the 430 r/min reference speed is the thermal criterion under load, the 750 r/min limiting speed is the mechanical ceiling; large 294 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 29488 EM.
- The 9000/32000 kN ratings and 410000 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
What are the dimensions and ratings of the 29488 EM?
A 29488 EM measures 440 mm bore × 780 mm outside diameter × 206 mm width (17.323 × 30.709 × 8.11 in). From SKF catalogue PUB BU/P1 17000: dynamic C 9000 kN, static C0 32000 kN, fatigue limit Pu 2320 kN, reference speed 430 r/min, limiting speed 750 r/min, mass about 410000 g. Minimum axial load factor A 91 must be maintained in service.
How is the 29488 EM designation read?
294 is the dimension series (heavy 294 series) and 88 the 440 mm bore (code 88 × 5); EM is the cage execution (machined brass EM cage). The sphered housing washer provides self-alignment.
Why is the minimum axial load (A 91) so important?
Spherical roller thrust bearings skid and smear immediately when run unloaded — on large sizes factor A 91 corresponds to a substantial force. Springs, oil lift or the rotor/load weight must be applied before rotation, including cold test runs.
Can the 29488 EM 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.
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.