81117-TN bearing: complete specifications & equivalents
The 81117-TN is a ISO 104 radial bearing sized 85 x 110 x 19 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 85 mm |
| Outer diameter D | 110 mm |
| Width B | 19 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 88 kN |
| Basic static load rating C0 | 365 kN |
| Fatigue load limit Pu | 37.5 kN |
| Reference speed (thermal) | 1500 rpm |
| Limiting speed (mechanical) | 3000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 420 g |
| Manufacturer designation | 81117 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 | 3.346 in |
|---|---|
| Outer diameter D | 4.331 in |
| Width B | 0.748 in |
| ISO bore code | 17 |
| Radial section height (D−d)/2 | 12.5 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) | 16 of 34 |
| Bore above smallest 81100-series size | 70 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 81117-TN model number is decoded
The light 811 series bearing 81117 TN carries pure axial load at low to moderate speed: 88 kN dynamic and 365 kN static across a 85×110 mm washer pair, 19 mm overall height. The designation 81117 TN states 811 series, 85 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 three components are separable and interchangeable within the size: WS shaft washer, K-cage roller set, GS housing washer, all running on flat, square seats; the glass fibre reinforced PA66 TN cage is standard for this size. Minimum axial load is explicit at factor A 0.011: below F_am = A·n² (or the catalogue's slow-speed floor) the cylindrical rollers skid; springs or the rotor's own weight are part of the selection, not an accessory. 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
- 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
- slewing and turntable pivots with predominantly axial force
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
- false brinelling and rust-red witness marks on standby machines under external vibration
- cage wear from rollers being dragged through unloaded zones under fluctuating thrust
Selection pitfalls — read before you substitute
- At 85 mm bore the minimum load (A 0.011) 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.
- 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 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 81117 TN size.
- the 1,500 r/min reference speed is the thermal criterion under load, the 3,000 r/min limiting speed is mechanical and oil lubrication typically raises the usable figure.
- The 88/365 kN ratings and 420 g mass are SKF catalogue values transcribed from ch. 11.1 of PUB BU/P1 17000 (PDF table page 892); 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
What are the dimensions and ratings of the 81117 TN?
A 81117 TN measures 85 mm bore × 110 mm outside diameter × 19 mm width (3.346 × 4.331 × 0.748 in). From SKF catalogue PUB BU/P1 17000: dynamic C 88 kN, static C0 365 kN, fatigue limit Pu 37.5 kN, reference speed 1,500 r/min, limiting speed 3,000 r/min, mass about 420 g. Raceway diameters Ea 87 mm / Eb 108 mm and minimum load factor A 0.011 guide the seat design.
How is the 81117 TN designation read?
The first three digits 811 give the dimension series (light 811 series); 17 encodes the 85 mm bore (code 17 × 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 81117 TN need a minimum axial load?
Below factor A 0.011 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.
Can the 81117 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.
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.