51106-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 51106-SKF model number is decoded

51106 is SKF's 30 mm-bore single-direction thrust ball bearing in the 51100 series to the ISO 104 dimension plan, with a flat housing seating surface, measuring 30×47×11 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 06 encode the bore as 30 mm (code 06 × 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 30×47×11 mm (1.181×1.85×0.433 in), 8.5 mm radial section, C 19 kN, C0 43 kN, Pu 1.6 kN. reference speed 6,000 r/min (thermal) and limiting speed 8,500 r/min (mechanical), catalogue mass 63 g. Washer-annulus check: the π/4·(D²−d²) contact annulus of 51106 covers about 1,028 mm², distributing C0 43 kN over a mean track circle of π·dm ≈ 121 mm. Imperial cross-check for procurement drawings: 1.181 in bore, 1.85 in OD, 0.433 in height, and the 63 g catalogue mass converts to 0.063 kg (2.2 oz). Stack/annulus proportions: the 11 mm axial stack over the 1,028 mm² washer annulus gives 10.70 mm of height per annular square millimetre ×10⁻³, and at 63 g the bearing holds about 682.5 kN of C0 per kilogram. Speed-ratio note for this exact unit: the reference speed is 6,000 r/min against a 8,500 r/min limiting speed, a reference-to-limit ratio of 0.71. Preload at the mechanical ceiling: repeating Fam ≈ A·(n·dm/1000)² with factor A 0.0096 at the 8,500 r/min limiting speed raises the required axial preload to about 1.0 kN; the reference-speed value 512 N is the thermal design point. 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 30 mm size the pressed cage and separable washers make the bearing interchangeable across brands on the ISO 104 plan, but the SKF ratings 19/43 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

• 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 11 mm stack; thrust-ball bearings on horizontal shafts should have the shaft washer (the tight one) against the rotating element.
• When the housing seat cannot be machined square to the 30 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.
• 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 19 kN track before first rotation.
• 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 51106 as the single flat pressed steel execution; other order numbers of the 51106 size are different products and may carry different ratings or seating geometry — always quote the full designation when purchasing.