51172-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 51172-F model number is decoded

The 51100 series order number 51172 F is a SKF single-direction thrust ball bearing for a 360 mm seat, built to ISO 104, with a flat housing seating surface, 360×440×65 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 360×440×65 mm (14.173×17.323×2.559 in), 40.0 mm radial section, C 390 kN, C0 2080 kN, Pu 38 kN. reference speed 750 r/min (thermal) and limiting speed 1,100 r/min (mechanical), catalogue mass 22000 g. Track-circle loading: per millimetre of mean track circumference the 390 kN dynamic rating corresponds to roughly 0.31 kN/mm of π·dm track, a useful comparison against the other dimension series of the 360 mm bore. Section proportions: the 40.0 mm radial section compares with 360 mm of bore (section/bore ≈ 0.11) and the 65 mm height is 1.63× that section — the proportions that identify the 51100 envelope at a glance. Static-first selection data: 2080 kN C0 spread across the 65 mm stack gives 32.0 kN of static rating per height millimetre, and the 22000 g mass/C0 ratio is about 11 g per static kN — crane-hook and screw positions are normally sized on these two figures. Preload at the mechanical ceiling: repeating Fam ≈ A·(n·dm/1000)² with factor A 22 at the 1,100 r/min limiting speed raises the required axial preload to about 4259.2 kN; the reference-speed value 1980.0 kN is the thermal design point. Speed band width for this size is 350 r/min between reference and limiting (1.47× ratio); lubrication, preload and heat removal decide where inside that band 51172 F can actually run. 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 440 mm OD ball complement is large enough that cage centrifugal forces dictate a machined guide, which is also why the 2080 kN C0 figure dominates selection of this order number.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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 390 kN track before first rotation.
• When the housing seat cannot be machined square to the 360 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.
• Keep the applied thrust above Fam ≈ A·(n·dm/1000)² with the printed factor A 22; for 51172 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.
• The third digit grades the section: 511 light, then 512, 513 and 514 progressively taller and heavier at the same bore — select from 390/2080 kN and the available 440 mm OD, never substitute a lighter series for a heavier one without rechecking C and C0.
• The 390/2080 kN figures belong to 51172 F specifically (the single flat machined steel execution of 51172); suffixed, sphered and counterpart-series order numbers are separate articles, so write the complete designation on the order and the maintenance record.