51113-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 51113-SKF model number is decoded

The 51100 series order number 51113 is a SKF single-direction thrust ball bearing for a 65 mm seat, built to ISO 104, with a flat housing seating surface, 65×90×18 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 13 decodes to 65 mm (code 13 × 5) under the same 00/01/02/03-exception, ×5 rule SKF uses across its coded bearing ranges. the suffix-free listing carries the catalogue default: a pressed (stamped sheet-steel) ball-cage assembly, light and quiet, used across the small and medium sizes. Envelope 65×90×18 mm (2.559×3.543×0.709 in), 12.5 mm radial section, C 37.7 kN, C0 108 kN, Pu 4 kN. reference speed 3,400 r/min (thermal) and limiting speed 4,800 r/min (mechanical), catalogue mass 330 g. Washer-annulus check: the π/4·(D²−d²) contact annulus of 51113 covers about 3,043 mm², distributing C0 108 kN over a mean track circle of π·dm ≈ 243 mm. Envelope economics: the 18 mm axial height over a 12.5 mm radial section yields 2.1 kN of dynamic capacity per height millimetre, and the bearing weighs 330 g for 37.7 kN C — about 9 g per rated kN. Speed planning separates the two ceilings mechanically: the pressed cage and balls tolerate 4,800 r/min while thermal balance under catalogue load sets the 3,400 r/min reference; at dm ≈ 77.5 mm the corresponding dn is approximately 372k mm·r/min. Load balance: C0 108 kN against C 37.7 kN gives a 2.86 ratio — thrust ball bearings are chosen on static rating and F_a/C0 far more often than on L10 life, while Pu 4 kN enters the adjusted-life check. Bore-to-OD planning: OD 90 over bore 65 is a 1.38× step for this size, and the 18 mm height gives a bore/height ratio of 3.61; use these ratios when the housing recess around the 65 mm shaft is the first constraint. 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. On this 65 mm size the pressed cage and separable washers make the bearing interchangeable across brands on the ISO 104 plan, but the SKF ratings 37.7/108 kN are this catalogue's figures — confirm the replacement order's ratings rather than swapping on envelope alone.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• The 51113 is a pure axial bearing: it must never be subjected to radial load — any radial force on the 65 mm shaft has to be carried by a radial bearing mounted alongside it.
• The third digit grades the section: 511 light, then 512, 513 and 514 progressively taller and heavier at the same bore — select from 37.7/108 kN and the available 90 mm OD, never substitute a lighter series for a heavier one without rechecking C and C0.
• When the housing seat cannot be machined square to the 65 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 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 51113 as the single flat pressed steel execution; other order numbers of the 51113 size are different products and may carry different ratings or seating geometry — always quote the full designation when purchasing.