81106-TN bearing: complete specifications & equivalents
The 81106-TN is a ISO 104 radial bearing sized 30 x 47 x 11 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 30 mm |
| Outer diameter D | 47 mm |
| Width B | 11 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 27 kN |
| Basic static load rating C0 | 78 kN |
| Fatigue load limit Pu | 7.65 kN |
| Reference speed (thermal) | 3000 rpm |
| Limiting speed (mechanical) | 6000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 57 g |
| Manufacturer designation | 81106 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 | 1.181 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.433 in |
| ISO bore code | 06 |
| Radial section height (D−d)/2 | 8.5 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) | 5 of 34 |
| Bore above smallest 81100-series size | 15 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 81106-TN model number is decoded
Where a thrust ball bearing of the same envelope is exhausted, 81106 TN replaces the ball complement with cylindrical rollers: 30 mm bore, 47 mm OD, rated 78 kN static for steady hook and screw loads. The designation 81106 TN states 811 series, 30 mm bore, glass fibre reinforced PA66 TN cage; shaft and housing washers are also orderable separately as WS and GS parts of the same size. 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 4.90e-4. One direction only: 81106 TN cannot be reversed to take opposite thrust — mirror a second bearing for reversing shafts, and keep housing and shaft seats square within the ISO 104 tolerances. In vertical shafts let the rotor weight provide the minimum load where possible; otherwise fit a spring pack above the housing washer, and verify the washer face is flooded with oil at first start.
Typical equipment & failure modes
Common applications
- slewing and turntable pivots with predominantly axial force
- crane hook crossheads carrying pure hook thrust while the hook swivels
- screw jack and lifting screw thrust positions under slow, steady load
- vertical electric motor and pump shafts whose rotor weight loads one bearing
Known failure patterns
- smearing at roller-raceway contacts during unloaded startup before the oil film or preload is established
- housing-washer rotation scored into an unmachined or loose seating face
- oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips
- condensation pitting in machines that run intermittently in humid environments
- cage wear from rollers being dragged through unloaded zones under fluctuating thrust
Selection pitfalls — read before you substitute
- At a 30 mm seat the 11 mm stack is easy to over-clamp — a cover torqued solid removes all roller clearance; shim to the catalogue endplay and keep factor A 4.90e-4 as the floor.
- Factor A 4.90e-4 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.
- Do not substitute a thrust ball bearing of the same ISO envelope by rating alone: the cylindrical rollers of 81106 TN need different minimum load and lubrication despite the shared 30×47 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 81106 TN size.
- The 27/78 kN ratings and 57 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 81106 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 4.90e-4 minimum load is present.
What are the dimensions and ratings of the 81106 TN?
A 81106 TN measures 30 mm bore × 47 mm outside diameter × 11 mm width (1.181 × 1.85 × 0.433 in). From SKF catalogue PUB BU/P1 17000: dynamic C 27 kN, static C0 78 kN, fatigue limit Pu 7.65 kN, reference speed 3,000 r/min, limiting speed 6,000 r/min, mass about 57 g. Raceway diameters Ea 31 mm / Eb 46 mm and minimum load factor A 4.90e-4 guide the seat design.
How is the 81106 TN designation read?
The first three digits 811 give the dimension series (light 811 series); 06 encodes the 30 mm bore (code 06 × 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 81106 TN need a minimum axial load?
Below factor A 4.90e-4 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.