51212-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 51212-SKF model number is decoded

51212 is SKF's 60 mm-bore single-direction thrust ball bearing in the 51200 series to the ISO 104 dimension plan, with a flat housing seating surface, measuring 60×95×26 mm. The separable set comprises a shaft washer (ground bore, tight fit on the shaft), a loose-bore housing washer and one ball-cage assembly, reacting axial force in one direction and carrying no radial load. in the 51xxx designation the first 1 marks a single-direction bearing with a flat housing seating surface; the third digit 1–4 grades the dimension series from the light 511 section through the heavy 514 section. the final two digits 12 encode the bore as 60 mm (code 12 × 5), the standard SKF bore-code rule shared with radial bearings. with no cage suffix this is the standard execution with a stamped sheet-steel ball-cage assembly (pressed cage) — the light, quiet and economical cage for small and medium thrust-ball sizes. Envelope 60×95×26 mm (2.362×3.74×1.024 in), 17.5 mm radial section, C 59.2 kN, C0 140 kN, Pu 5.1 kN. reference speed 2,800 r/min (thermal) and limiting speed 3,800 r/min (mechanical), catalogue mass 650 g. Load balance: C0 140 kN against C 59.2 kN gives a 2.36 ratio — thrust ball bearings are chosen on static rating and F_a/C0 far more often than on L10 life, while Pu 5.1 kN enters the adjusted-life check. Selection figures for 51212: the C0/C ratio is 2.36, Pu 5.1 kN is about 9 % of C, and the catalogue mass works out to roughly 11 g per millimetre of bore; the printed minimum-load factor is A 0.12. Light-load floor: Pu = 5.1 kN is the equivalent-load threshold below which the SKF adjusted-life equation credits very long life for 51212; the number is 9 % of the 59.2 kN dynamic rating. Mass and section check: 650 g inside the 60×95×26 mm outline leaves a 17.5 mm radial section, and the 140 kN static rating is 2.36× the dynamic rating — plan static safety and minimum preload against those figures. Envelope economics: the 26 mm axial height over a 17.5 mm radial section yields 2.3 kN of dynamic capacity per height millimetre, and the bearing weighs 650 g for 59.2 kN C — about 11 g per rated kN. 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 26 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 59.2 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 51212 against two-way load lifts the loose washer off its raceway.
• When the housing seat cannot be machined square to the 60 mm shaft, the sphered 53-series execution of this size with its U seat washer is the self-aligning counterpart of this flat 51200 bearing.
• 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.
• Identify the washers before fitting: the shaft washer has the ground, smaller bore and takes an interference fit on the 60 mm shaft, while the housing washer bore is larger and runs loose; swapping them locks the ball set and burns the tracks.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 51212 as the single flat pressed steel execution; other order numbers of the 51212 size are different products and may carry different ratings or seating geometry — always quote the full designation when purchasing.