51272-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 51272-F model number is decoded

The 51200 series order number 51272 F is a SKF single-direction thrust ball bearing for a 360 mm seat, built to ISO 104, with a flat housing seating surface, 360×500×110 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 72 decodes to 360 mm (code 72 × 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 360×500×110 mm (14.173×19.685×4.331 in), 70.0 mm radial section, C 741 kN, C0 4150 kN, Pu 73.5 kN. reference speed 500 r/min (thermal) and limiting speed 700 r/min (mechanical), catalogue mass 70000 g. Pitch-diameter arithmetic: dm = (360+500)/2 = 430.0 mm; at the 700 r/min limiting speed that corresponds to roughly 301k mm·r/min, the figure used when comparing cage speed demand across the thrust-ball series. Light-load floor: Pu = 73.5 kN is the equivalent-load threshold below which the SKF adjusted-life equation credits very long life for 51272 F; the number is 10 % of the 741 kN dynamic rating. Bore-to-OD planning: OD 500 over bore 360 is a 1.39× step for this size, and the 110 mm height gives a bore/height ratio of 3.27; use these ratios when the housing recess around the 360 mm shaft is the first constraint. Preload at the mechanical ceiling: repeating Fam ≈ A·(n·dm/1000)² with factor A 90 at the 700 r/min limiting speed raises the required axial preload to about 8154.1 kN; the reference-speed value 4160.3 kN is the thermal design point. Sizing arithmetic on the 360 mm bore: 741 kN C over the 70.0 mm radial section gives 10.6 kN per section millimetre, and the 110 mm stack height is 1.57× that section — proportions typical of a 51200 thrust section. 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. The F execution appears only at the 360 mm top end of the range: the 500 mm OD ball complement is large enough that cage centrifugal forces dictate a machined guide, which is also why the 4150 kN C0 figure dominates selection of this order number.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Keep the applied thrust above Fam ≈ A·(n·dm/1000)² with the printed factor A 90; for 51272 F a spring preload or the rotor weight is part of the selection at light load and high speed, because unloaded balls skid rather than roll.
• Identify the washers before fitting: the shaft washer has the ground, smaller bore and takes an interference fit on the 360 mm shaft, while the housing washer bore is larger and runs loose; swapping them locks the ball set and burns the tracks.
• The 51272 F is a pure axial bearing: it must never be subjected to radial load — any radial force on the 360 mm shaft has to be carried by a radial bearing mounted alongside it.
• Heat the shaft washer to at most 120 °C for mounting, or press it via a sleeve on its ground bore — force applied through the housing washer or the ball set brinells the 741 kN track before first rotation.
• Ordering discipline for 51272: the catalogue page quotes 51272 F and its 741/4150 kN ratings as one exact article; bare-number substitutions from another series or brand need a fresh dimension and rating check, not a like-for-like assumption.