89308-TN bearing: complete specifications & equivalents
The 89308-TN is a ISO 104 radial bearing sized 40 x 78 x 22 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 40 mm |
| Outer diameter D | 78 mm |
| Width B | 22 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 95 kN |
| Basic static load rating C0 | 365 kN |
| Fatigue load limit Pu | 36.5 kN |
| Reference speed (thermal) | 2000 rpm |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 480 g |
| Manufacturer designation | 89308 TN |
| Standard | ISO 104 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 11.1 cylindrical roller thrust bearings |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 11.1 cylindrical 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. 11.1 cylindrical 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 & 89300-series range
| Bore d | 1.575 in |
|---|---|
| Outer diameter D | 3.071 in |
| Width B | 0.866 in |
| ISO bore code | 08 |
| Radial section height (D−d)/2 | 19 mm |
| Smallest bore in 89300-series | 40 mm |
| Largest outer diameter in 89300-series | 210 mm |
| Width range across 89300-series | 22–54 mm |
| Bore position in 89300-series (smallest first) | 1 of 8 |
| Bore above smallest 89300-series size | 0 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 89308-TN model number is decoded
89308 TN is the rigid-washer thrust solution for a 40 mm shaft: unlike ball thrust types, the line contact of cylindrical rollers gives 95 kN C within just 22 mm of axial space, per the ISO 104 plan. In 89308 TN, 893 fixes the 78 mm OD and 22 mm height; 08 selects the 40 mm seat, and the glass fibre reinforced PA66 TN cage is the only execution suffix on these rigid-washer bearings. Rigid washers mean no self-alignment: the shaft and housing shoulders must be square and parallel to within the catalogue seat tolerances, or the rollers edge-load across the 22 mm height. Speed planning separates the 2,000 r/min thermal reference from the 4,000 r/min mechanical limiting speed. Thrust bearings govern the thermal speed of many vertical arrangements, and oil circulation raises the usable speed substantially above grease values. Mounting: locate the shaft washer on the 40 mm seat (it rotates and takes an interference fit), leave the housing washer a sliding fit in the 78 mm bore, and check the stack can tilt freely before clamping.
Typical equipment & failure modes
Common applications
- screw jack and lifting screw thrust positions under slow, steady load
- vertical electric motor and pump shafts whose rotor weight loads one bearing
- extruder and injection press screw thrust blocks at low speed
- rolling-mill screwdown mechanisms and press adjusters
Known failure patterns
- roller skidding and raceway glazing once the thrust falls below the catalogue minimum axial load (factor A)
- housing-washer rotation scored into an unmachined or loose seating face
- abrasive paste forming as dust bypasses the housing seals into the open washer set
- hard-particle indentation where oil or grease filtration is inadequate
- smearing at roller-raceway contacts during unloaded startup before the oil film or preload is established
Selection pitfalls — read before you substitute
- At a 40 mm seat the 22 mm stack is easy to over-clamp — a cover torqued solid removes all roller clearance; shim to the catalogue endplay and keep factor A 0.011 as the floor.
- Do not substitute a thrust ball bearing of the same ISO envelope by rating alone: the cylindrical rollers of 89308 TN need different minimum load and lubrication despite the shared 40×78 mm outline.
- The separable washers are not interchangeable across series: an 811 and an 812 washer for the same bore differ in OD and height — order WS/GS parts by the full 89308 TN size.
- Factor A 0.011 is a mounting requirement, not advice: below the minimum axial load the rollers skid at speed — most "mysterious" early thrust failures are unloaded running.
- Keep the glass fibre reinforced PA66 TN cage out of chemical contact with aggressive EP additives beyond its compatibility list; cage damage here redistributes rollers and destroys the washer in hours.
- The 95/365 kN ratings and 480 g mass are SKF catalogue values transcribed from ch. 11.1 of PUB BU/P1 17000 (PDF table page 890); mounting data — Ea/Eb raceway diameters and the minimum load factor A — appears in the running text because the structured record carries the boundary envelope only.
Frequently asked questions
Can the 89308 TN take reversing thrust?
No. It carries axial load in one direction only; reversing force unloads and impacts the roller set. Use a mirrored pair of bearings for reversing shafts, with a separate arrangement for radial load.
How should a 89308 TN be mounted?
Interference fit for the shaft washer, sliding fit for the housing washer, full-area square shoulders both sides, press on washer backs only, and shim the cover so the rollers turn freely while the factor-A 0.011 minimum load is present.
What are the dimensions and ratings of the 89308 TN?
A 89308 TN measures 40 mm bore × 78 mm outside diameter × 22 mm width (1.575 × 3.071 × 0.866 in). From SKF catalogue PUB BU/P1 17000: dynamic C 95 kN, static C0 365 kN, fatigue limit Pu 36.5 kN, reference speed 2,000 r/min, limiting speed 4,000 r/min, mass about 480 g. Raceway diameters Ea 44 mm / Eb 77 mm and minimum load factor A 0.011 guide the seat design.
How is the 89308 TN designation read?
The first three digits 893 give the dimension series (heavy 893 series); 08 encodes the 40 mm bore (code 08 × 5); the suffix denotes the glass fibre reinforced PA66 TN cage. WS and GS washers of the same size can be ordered separately.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 11.1 cylindrical roller thrust bearings on 2026-09-27. Read our editorial & correction policy.