81109-TN bearing: complete specifications & equivalents
The 81109-TN is a ISO 104 radial bearing sized 45 x 65 x 14 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 45 mm |
| Outer diameter D | 65 mm |
| Width B | 14 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 45 kN |
| Basic static load rating C0 | 153 kN |
| Fatigue load limit Pu | 15.3 kN |
| Reference speed (thermal) | 2200 rpm |
| Limiting speed (mechanical) | 4500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 130 g |
| Manufacturer designation | 81109 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 & 81100-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 2.559 in |
| Width B | 0.551 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 10 mm |
| Smallest bore in 81100-series | 15 mm |
| Largest outer diameter in 81100-series | 400 mm |
| Width range across 81100-series | 9–63 mm |
| Bore position in 81100-series (smallest first) | 8 of 34 |
| Bore above smallest 81100-series size | 30 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 81109-TN model number is decoded
In SKF catalogue PUB BU/P1 17000, 81109 TN denotes a cylindrical roller thrust bearing whose rollers run flat on hardened, ground washers — no radial capacity, one axial direction only, and a minimum axial load of factor A 0.0019. In 81109 TN, 811 fixes the 65 mm OD and 14 mm height; 09 selects the 45 mm seat, and the glass fibre reinforced PA66 TN cage is the only execution suffix on these rigid-washer bearings. The bearing takes thrust in one direction only — reverse loads lift the roller set off its track; arrange a mirrored second bearing for reversing duty, and keep the applied load above factor A 0.0019. The 130 g mass and 14 mm axial height sit between 45 and 65 mm washer diameters; check the seat shoulder spans the full ring face — a narrow shoulder causes washer fretting long before fatigue does. Press only on washer backs, never through the roller set; seat both washers against full-area square shoulders, and shim the housing cover so the minimum load (A 0.0019) is present without clamping the rollers.
Typical equipment & failure modes
Common applications
- extruder and injection press screw thrust blocks at low speed
- rolling-mill screwdown mechanisms and press adjusters
- slewing and turntable pivots with predominantly axial force
- crane hook crossheads carrying pure hook thrust while the hook swivels
Known failure patterns
- cage wear from rollers being dragged through unloaded zones under fluctuating thrust
- housing-washer rotation scored into an unmachined or loose seating face
- grease churning and overheating when a high-speed thrust position is over-packed
- brinelling of washer raceways from impact or mounting force applied through the rolling elements
- roller skidding and raceway glazing once the thrust falls below the catalogue minimum axial load (factor A)
Selection pitfalls — read before you substitute
- At 45 mm bore the minimum load (A 0.0019) is still small, but a vertical shaft at rest loses it entirely — specify springs or check the rotor weight exceeds F_am at zero speed.
- the 2,200 r/min reference speed is the thermal criterion under load, the 4,500 r/min limiting speed is mechanical and oil lubrication typically raises the usable figure.
- The 45/153 kN ratings assume flat, full-support washer seats; a housing face narrower than the 65 mm washer OD invalidates the rating through edge stress.
- Factor A 0.0019 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 45/153 kN ratings and 130 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
How should a 81109 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 0.0019 minimum load is present.
What are the dimensions and ratings of the 81109 TN?
A 81109 TN measures 45 mm bore × 65 mm outside diameter × 14 mm width (1.772 × 2.559 × 0.551 in). From SKF catalogue PUB BU/P1 17000: dynamic C 45 kN, static C0 153 kN, fatigue limit Pu 15.3 kN, reference speed 2,200 r/min, limiting speed 4,500 r/min, mass about 130 g. Raceway diameters Ea 47 mm / Eb 63 mm and minimum load factor A 0.0019 guide the seat design.
How is the 81109 TN designation read?
The first three digits 811 give the dimension series (light 811 series); 09 encodes the 45 mm bore (code 09 × 5); the suffix denotes the glass fibre reinforced PA66 TN cage. WS and GS washers of the same size can be ordered separately.
Why does 81109 TN need a minimum axial load?
Below factor A 0.0019 the cylindrical rollers skid instead of rolling, glazing and smearing the washer tracks. Springs, preload shims or rotor weight must keep the thrust above the catalogue minimum, especially during unloaded starts.
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.