51117-SKF bearing: complete specifications & equivalents

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-28

Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); 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.

Cross references & equivalents

Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.

How the 51117-SKF model number is decoded

The 51100 series order number 51117 is a SKF single-direction thrust ball bearing for a 85 mm seat, built to ISO 104, with a flat housing seating surface, 85×110×19 mm boundary dimensions. Three separable parts make the set: the tight-bore shaft washer that locates on the shaft, the loose-bore housing washer in its register, and the ball-cage assembly; load is purely axial and acts in one direction. reading 51xxx as a code: the 1 after 5 identifies one load direction and a flat seat, and the next digit ranks the section 1 (light) to 4 (heavy) before the two-digit bore code. bore code 17 decodes to 85 mm (code 17 × 5) under the same 00/01/02/03-exception, ×5 rule SKF uses across its coded bearing ranges. the suffix-free listing carries the catalogue default: a pressed (stamped sheet-steel) ball-cage assembly, light and quiet, used across the small and medium sizes. Envelope 85×110×19 mm (3.346×4.331×0.748 in), 12.5 mm radial section, C 44.9 kN, C0 146 kN, Pu 5.4 kN. reference speed 3,000 r/min (thermal) and limiting speed 4,300 r/min (mechanical), catalogue mass 440 g. Load balance: C0 146 kN against C 44.9 kN gives a 3.25 ratio — thrust ball bearings are chosen on static rating and F_a/C0 far more often than on L10 life, while Pu 5.4 kN enters the adjusted-life check. Envelope economics: the 19 mm axial height over a 12.5 mm radial section yields 2.4 kN of dynamic capacity per height millimetre, and the bearing weighs 440 g for 44.9 kN C — about 10 g per rated kN. Sizing arithmetic on the 85 mm bore: 44.9 kN C over the 12.5 mm radial section gives 3.6 kN per section millimetre, and the 19 mm stack height is 1.52× that section — proportions typical of a 51100 thrust section. Speed band width for this size is 1,300 r/min between reference and limiting (1.43× ratio); lubrication, preload and heat removal decide where inside that band 51117 can actually run. Washer-annulus check: the π/4·(D²−d²) contact annulus of 51117 covers about 3,829 mm², distributing C0 146 kN over a mean track circle of π·dm ≈ 306 mm. Execution note for this order number: the flat housing seating surface must be machined square to the shaft axis and supported across the full washer face — unlike the sphered 53-series execution this pressed-cage 51-series bearing has no self-aligning capability at all, so seat squareness is checked at mounting, not compensated in service. Inspection after removal of a 19 mm-high stack means checking both washer faces: the loose housing washer often shows the first false-brinell marks under machine vibration even though the tight shaft washer carries the rotating load of 44.9 kN C.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• The three components are separable and interchangeable within the ISO 104 size, but keep this bearing's parts together in service and never combine washers from different manufacturers or a worn washer with a new ball set.
• A 51-series bearing reacts thrust in one direction only — reversing positions need a mirrored single-direction pair or a 52-series double-direction unit; fitting a single 51117 against two-way load lifts the loose washer off its raceway.
• When the housing seat cannot be machined square to the 85 mm shaft, the sphered 53-series execution of this size with its U seat washer is the self-aligning counterpart of this flat 51100 bearing.
• On vertical shafts retain the loose housing washer positively with a cover or ring and verify the grease fill does not drain out of the 19 mm stack; thrust-ball bearings on horizontal shafts should have the shaft washer (the tight one) against the rotating element.
• The 44.9/146 kN figures belong to 51117 specifically (the single flat pressed steel execution of 51117); suffixed, sphered and counterpart-series order numbers are separate articles, so write the complete designation on the order and the maintenance record.