51110-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 51110-SKF model number is decoded

The 51100 series order number 51110 is a SKF single-direction thrust ball bearing for a 50 mm seat, built to ISO 104, with a flat housing seating surface, 50×70×14 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 10 decodes to 50 mm (code 10 × 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 50×70×14 mm (1.969×2.756×0.551 in), 10.0 mm radial section, C 27 kN, C0 75 kN, Pu 2.8 kN. reference speed 4,300 r/min (thermal) and limiting speed 6,300 r/min (mechanical), catalogue mass 160 g. Speed-ratio note for this exact unit: the reference speed is 4,300 r/min against a 6,300 r/min limiting speed, a reference-to-limit ratio of 0.68. Sizing arithmetic on the 50 mm bore: 27 kN C over the 10.0 mm radial section gives 2.7 kN per section millimetre, and the 14 mm stack height is 1.40× that section — proportions typical of a 51100 thrust section. Minimum-load arithmetic: with dm ≈ 60.0 mm and factor A 0.029, Fam ≈ A·(n·dm/1000)² at the 4,300 r/min reference speed is about 1.9 kN for 51110; below that preload the balls skid and smear the tracks. Preload at the mechanical ceiling: repeating Fam ≈ A·(n·dm/1000)² with factor A 0.029 at the 6,300 r/min limiting speed raises the required axial preload to about 4.1 kN; the reference-speed value 1.9 kN is the thermal design point. Speed band width for this size is 2,000 r/min between reference and limiting (1.47× ratio); lubrication, preload and heat removal decide where inside that band 51110 can actually run. 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 14 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 27 kN C.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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 51110 against two-way load lifts the loose washer off its raceway.
• 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.
• The third digit grades the section: 511 light, then 512, 513 and 514 progressively taller and heavier at the same bore — select from 27/75 kN and the available 70 mm OD, never substitute a lighter series for a heavier one without rechecking C and C0.
• 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 14 mm stack; thrust-ball bearings on horizontal shafts should have the shaft washer (the tight one) against the rotating element.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 51110 as the single flat pressed steel execution; other order numbers of the 51110 size are different products and may carry different ratings or seating geometry — always quote the full designation when purchasing.