51188-F 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 51188-F model number is decoded

The 51100 series order number 51188 F is a SKF single-direction thrust ball bearing for a 440 mm seat, built to ISO 104, with a flat housing seating surface, 440×540×80 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 88 decodes to 440 mm (code 88 × 5) under the same 00/01/02/03-exception, ×5 rule SKF uses across its coded bearing ranges. the F suffix denotes a steel cage machined from solid and centred on the balls, reserved for the largest OD sizes whose ball mass is beyond pressed-cage guidance. Envelope 440×540×80 mm (17.323×21.26×3.15 in), 50.0 mm radial section, C 527 kN, C0 3250 kN, Pu 55 kN. reference speed 600 r/min (thermal) and limiting speed 850 r/min (mechanical), catalogue mass 42000 g. Washer-annulus check: the π/4·(D²−d²) contact annulus of 51188 F covers about 76,969 mm², distributing C0 3250 kN over a mean track circle of π·dm ≈ 1,539 mm. Speed band width for this size is 250 r/min between reference and limiting (1.42× ratio); lubrication, preload and heat removal decide where inside that band 51188 F can actually run. Mass and section check: 42000 g inside the 440×540×80 mm outline leaves a 50.0 mm radial section, and the 3250 kN static rating is 6.17× the dynamic rating — plan static safety and minimum preload against those figures. Rating split for documentation: dynamic 527 kN (L10 life), static 3250 kN (safety factor s0), fatigue limit 55 kN (adjusted life) — three different uses of three different numbers for 51188 F, none interchangeable with another. Selection figures for 51188 F: the C0/C ratio is 6.17, Pu 55 kN is about 10 % of C, and the catalogue mass works out to roughly 95 g per millimetre of bore; the printed minimum-load factor is A 55. Large-size execution note: the F machined steel cage exists because the ball complement and pitch diameter of the biggest 512-series sizes are beyond pressed-cage guidance; the steel cage is machined from solid, ball-centred, and its heavier mass must be supported by genuine oil or grease flow at start-up — never mount an F bearing dry for a trial rotation. Mounting note for the 80 mm F stack: induction-heat the shaft washer only — the machined steel cage rides the balls and must never be tapped, and first rotation should be a slow unloaded bedding run before the working thrust goes on.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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 80 mm stack; thrust-ball bearings on horizontal shafts should have the shaft washer (the tight one) against the rotating element.
• When the housing seat cannot be machined square to the 440 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.
• The third digit grades the section: 511 light, then 512, 513 and 514 progressively taller and heavier at the same bore — select from 527/3250 kN and the available 540 mm OD, never substitute a lighter series for a heavier one without rechecking C and C0.
• 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.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 51188 F as the single flat machined steel execution; other order numbers of the 51188 size are different products and may carry different ratings or seating geometry — always quote the full designation when purchasing.