51226 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 51226 model number is decoded

Listed in SKF 17000 chapter 5, 51226 is an ISO 104 single-direction thrust ball bearing, 130 mm bore and 190 mm OD on a flat housing seat, standing 45 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 26: bore 130 mm (code 26 × 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 130×190×45 mm (5.118×7.48×1.772 in), 30.0 mm radial section, C 186 kN, C0 585 kN, Pu 17 kN. reference speed 1,400 r/min (thermal) and limiting speed 2,000 r/min (mechanical), catalogue mass 4000 g. At the printed limiting speed of 2,000 r/min the mean pitch diameter dm ≈ 160.0 mm implies a dn value around 320k mm·r/min; the 1,400 r/min reference speed is the thermal-planning value under catalogue load. Selection figures for 51226: the C0/C ratio is 3.15, Pu 17 kN is about 9 % of C, and the catalogue mass works out to roughly 31 g per millimetre of bore; the printed minimum-load factor is A 1.8. Mass and section check: 4000 g inside the 130×190×45 mm outline leaves a 30.0 mm radial section, and the 585 kN static rating is 3.15× the dynamic rating — plan static safety and minimum preload against those figures. Imperial cross-check for procurement drawings: 5.118 in bore, 7.48 in OD, 1.772 in height, and the 4000 g catalogue mass converts to 4.000 kg (141.1 oz). Rating split for documentation: dynamic 186 kN (L10 life), static 585 kN (safety factor s0), fatigue limit 17 kN (adjusted life) — three different uses of three different numbers for 51226, none interchangeable with another. 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 130 mm size the pressed cage and separable washers make the bearing interchangeable across brands on the ISO 104 plan, but the SKF ratings 186/585 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

• 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 186 kN track before first rotation.
• The third digit grades the section: 511 light, then 512, 513 and 514 progressively taller and heavier at the same bore — select from 186/585 kN and the available 190 mm OD, never substitute a lighter series for a heavier one without rechecking C and C0.
• The 51226 is a pure axial bearing: it must never be subjected to radial load — any radial force on the 130 mm shaft has to be carried by a radial bearing mounted alongside it.
• Keep the applied thrust above Fam ≈ A·(n·dm/1000)² with the printed factor A 1.8; for 51226 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 186/585 kN figures belong to 51226 specifically (the single flat pressed steel execution of 51226); suffixed, sphered and counterpart-series order numbers are separate articles, so write the complete designation on the order and the maintenance record.