294-670-EM bearing: complete specifications & equivalents
The 294-670-EM is a ISO 104 radial bearing sized 670 x 1150 x 290 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 670 mm |
| Outer diameter D | 1150 mm |
| Width B | 290 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 15400 kN |
| Basic static load rating C0 | 68000 kN |
| Fatigue load limit Pu | 4500 kN |
| Reference speed (thermal) | 240 rpm |
| Limiting speed (mechanical) | 450 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1210000 g |
| Manufacturer designation | 294/670 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 | 26.378 in |
|---|---|
| Outer diameter D | 45.276 in |
| Width B | 11.417 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 240 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) | 38 of 46 |
| Bore above smallest 29400-series size | 610 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 294-670-EM model number is decoded
294/670 EM is the classic hook-block and screw-end thrust bearing: 670 mm shaft washer bore, 1150 mm OD, minimum axial load factor A 440, and free rotation under load thanks to the spherical geometry. SKF suffixes on spherical roller thrust bearings describe cages: E the steel window cage for the larger sizes, EM the machined brass execution, EF the extra-large steel-cage design; 294/670 EM is the machined brass EM cage. A minimum axial load of factor A 440 must be maintained — in the large 294 sizes this is a real force (often supplied by springs, oil pressure or the rotor weight), below it the rollers skid and smear. Selection arithmetic: C 15400 kN against C0 68000 kN gives a C0/C ratio of 4.42 — thrust bearings are chosen on static rating and F_a/C0 more often than on L10 life. Verify the minimum axial load (factor A 440) immediately at commissioning — a cold start unloaded smears the rollers; spring preload or rotor weight must be present before the shaft rotates.
Typical equipment & failure modes
Common applications
- crane hook assemblies where the hook block turns under full load
- injection moulding machine and extruder screw thrust positions
- vertical hydro generators and large vertical pump motors
- coal mill, cement mill and sugar mill thrust bearings under shock 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
- grease churning and overheating when a high-speed thrust position is over-packed
- condensation pitting in machines that run intermittently in humid environments
- smearing at roller-raceway contacts during unloaded startup before the oil film or preload is established
Selection pitfalls — read before you substitute
- At 670 mm bore and 1210 kg, mounting is a rigging operation: sphered seats, oil injection and rotation checks under preload follow the large-bearing mounting manual, not general practice.
- 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 294/670 EM.
- E, EM and EF suffixes are cage designs for different size bands, not quality grades: substitute only within the same envelope and check the lubricant compatibility of the cage material.
- Minimum load factor A 440 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 15400/68000 kN ratings and 1210000 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 destroys a spherical roller thrust bearing?
Unloaded rotation below A 440 (roller smearing), interrupted oil supply on the large sizes, a missing sphered seating washer that removes alignment, and contamination. Limiting speed here is 450 r/min.
Which dimensions does the 294/670 EM have?
A 294/670 EM measures 670 mm bore × 1150 mm outside diameter × 290 mm width (26.378 × 45.276 × 11.417 in). From SKF catalogue PUB BU/P1 17000: dynamic C 15400 kN, static C0 68000 kN, fatigue limit Pu 4500 kN, reference speed 240 r/min, limiting speed 450 r/min, mass about 1210000 g. Minimum axial load factor A 440 must be maintained in service.
What is the difference between 292, 293 and 294 series?
292 is the light, fastest section; 293 the medium; 294 the heaviest with the largest OD per bore and the greatest thrust capacity. 294/670 EM is the heavy 294 series, 670×1150×290 mm.
What do E, EM and EF mean on 294/670 EM?
They are cage designs for different size bands: E is the stamped steel window cage of the current design, EM the machined brass cage for heavy/slow sizes, EF the steel cage for extra-large bearings — not quality grades. This bearing carries the machined brass EM cage.
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.