81103-TN bearing: complete specifications & equivalents
The 81103-TN is a ISO 104 radial bearing sized 17 x 30 x 9 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 17 mm |
| Outer diameter D | 30 mm |
| Width B | 9 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 12.2 kN |
| Basic static load rating C0 | 31.5 kN |
| Fatigue load limit Pu | 2.85 kN |
| Reference speed (thermal) | 4300 rpm |
| Limiting speed (mechanical) | 8500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 27 g |
| Manufacturer designation | 81103 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 | 0.669 in |
|---|---|
| Outer diameter D | 1.181 in |
| Width B | 0.354 in |
| ISO bore code | 03 |
| Radial section height (D−d)/2 | 6.5 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) | 2 of 34 |
| Bore above smallest 81100-series size | 2 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 81103-TN model number is decoded
SKF supplies 81103 TN as a separable thrust bearing: the 17 mm shaft washer (WS), the glass fibre reinforced PA66 TN cage holding short cylindrical rollers, and the 30 mm housing washer (GS) can be ordered and mounted individually. In 81103 TN, 811 fixes the 30 mm OD and 9 mm height; 03 selects the 17 mm seat, and the glass fibre reinforced PA66 TN cage is the only execution suffix on these rigid-washer bearings. Small sizes ship with glass-fibre PA66 TN cages for quiet, low-friction running; the 12.2 kN rating assumes oil or grease reaching the full washer face. Minimum axial load is explicit at factor A 7.90e-5: 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. 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 7.90e-5) is present without clamping the rollers.
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
- roller skidding and raceway glazing once the thrust falls below the catalogue minimum axial load (factor A)
- washer back-face fretting where the seat is too narrow to support the full ring face
- oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips
- electrical erosion of raceways on VFD-driven shafts without grounding or insulation
- smearing at roller-raceway contacts during unloaded startup before the oil film or preload is established
Selection pitfalls — read before you substitute
- At a 17 mm seat the 9 mm stack is easy to over-clamp — a cover torqued solid removes all roller clearance; shim to the catalogue endplay and keep factor A 7.90e-5 as the floor.
- Do not substitute a thrust ball bearing of the same ISO envelope by rating alone: the cylindrical rollers of 81103 TN need different minimum load and lubrication despite the shared 17×30 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 81103 TN size.
- 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 4,300 r/min reference speed is the thermal criterion under load, the 8,500 r/min limiting speed is mechanical and oil lubrication typically raises the usable figure.
- The 12.2/31.5 kN ratings and 27 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
What are the dimensions and ratings of the 81103 TN?
A 81103 TN measures 17 mm bore × 30 mm outside diameter × 9 mm width (0.669 × 1.181 × 0.354 in). From SKF catalogue PUB BU/P1 17000: dynamic C 12.2 kN, static C0 31.5 kN, fatigue limit Pu 2.85 kN, reference speed 4,300 r/min, limiting speed 8,500 r/min, mass about 27 g. Raceway diameters Ea 18 mm / Eb 29 mm and minimum load factor A 7.90e-5 guide the seat design.
How is the 81103 TN designation read?
The first three digits 811 give the dimension series (light 811 series); 03 encodes the 17 mm bore (code 03 = 17 mm); the suffix denotes the glass fibre reinforced PA66 TN cage. WS and GS washers of the same size can be ordered separately.
Why does 81103 TN need a minimum axial load?
Below factor A 7.90e-5 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 81103 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.