51207-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 51207-SKF model number is decoded

Listed in SKF 17000 chapter 5, 51207 is an ISO 104 single-direction thrust ball bearing, 35 mm bore and 62 mm OD on a flat housing seat, standing 18 mm high before installation. The bearing is delivered as separate, interchangeable parts: a ground-bore shaft washer, a loose-bore housing washer and the ball-cage assembly between them, designed for one axial load direction only. 51xxx breaks down as 5 for thrust ball, 1 for one load direction on a flat seat, a section digit 1–4 light-to-heavy, then the two-digit bore code. reading the ending 07: bore 35 mm (code 07 × 5) for this single-direction size, via the standard exceptions 00/01/02/03 and ×5 above them. no cage suffix means the standard stamped steel retainer — a pressed sheet-metal ball-cage assembly that covers the bulk of the thrust-ball assortment. Envelope 35×62×18 mm (1.378×2.441×0.709 in), 13.5 mm radial section, C 35.1 kN, C0 73.5 kN, Pu 2.7 kN. reference speed 4,000 r/min (thermal) and limiting speed 5,600 r/min (mechanical), catalogue mass 220 g. Preload at the mechanical ceiling: repeating Fam ≈ A·(n·dm/1000)² with factor A 0.028 at the 5,600 r/min limiting speed raises the required axial preload to about 2.1 kN; the reference-speed value 1.1 kN is the thermal design point. Bore-to-OD planning: OD 62 over bore 35 is a 1.77× step for this size, and the 18 mm height gives a bore/height ratio of 1.94; use these ratios when the housing recess around the 35 mm shaft is the first constraint. Stack/annulus proportions: the 18 mm axial stack over the 2,057 mm² washer annulus gives 8.75 mm of height per annular square millimetre ×10⁻³, and at 220 g the bearing holds about 334.1 kN of C0 per kilogram. At the printed limiting speed of 5,600 r/min the mean pitch diameter dm ≈ 48.5 mm implies a dn value around 272k mm·r/min; the 4,000 r/min reference speed is the thermal-planning value under catalogue load. Pitch-diameter arithmetic: dm = (35+62)/2 = 48.5 mm; at the 5,600 r/min limiting speed that corresponds to roughly 272k mm·r/min, the figure used when comparing cage speed demand across the thrust-ball series. 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 18 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 35.1 kN C.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• The third digit grades the section: 511 light, then 512, 513 and 514 progressively taller and heavier at the same bore — select from 35.1/73.5 kN and the available 62 mm OD, never substitute a lighter series for a heavier one without rechecking C and C0.
• Identify the washers before fitting: the shaft washer has the ground, smaller bore and takes an interference fit on the 35 mm shaft, while the housing washer bore is larger and runs loose; swapping them locks the ball set and burns the tracks.
• 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 18 mm stack; thrust-ball bearings on horizontal shafts should have the shaft washer (the tight one) against the rotating element.
• 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 51207 against two-way load lifts the loose washer off its raceway.
• Ordering discipline for 51207: the catalogue page quotes 51207 and its 35.1/73.5 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.