51136-M 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 51136-M model number is decoded

Listed in SKF 17000 chapter 5, 51136 M is an ISO 104 single-direction thrust ball bearing, 180 mm bore and 225 mm OD on a flat housing seat, standing 34 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 36: bore 180 mm (code 36 × 5) for this single-direction size, via the standard exceptions 00/01/02/03 and ×5 above them. M-cage execution: brass machined from solid and ball-centred, giving heavier guidance than the standard pressed retainer at the top end of the thrust-ball range. Envelope 180×225×34 mm (7.087×8.858×1.339 in), 22.5 mm radial section, C 135 kN, C0 570 kN, Pu 15 kN. reference speed 1,500 r/min (thermal) and limiting speed 2,200 r/min (mechanical), catalogue mass 3500 g. Speed-ratio note for this exact unit: the reference speed is 1,500 r/min against a 2,200 r/min limiting speed, a reference-to-limit ratio of 0.68. Load balance: C0 570 kN against C 135 kN gives a 4.22 ratio — thrust ball bearings are chosen on static rating and F_a/C0 far more often than on L10 life, while Pu 15 kN enters the adjusted-life check. Minimum-load arithmetic: with dm ≈ 202.5 mm and factor A 1.7, Fam ≈ A·(n·dm/1000)² at the 1,500 r/min reference speed is about 156.8 kN for 51136 M; below that preload the balls skid and smear the tracks. Speed band width for this size is 700 r/min between reference and limiting (1.47× ratio); lubrication, preload and heat removal decide where inside that band 51136 M can actually run. Stack/annulus proportions: the 34 mm axial stack over the 14,314 mm² washer annulus gives 2.38 mm of height per annular square millimetre ×10⁻³, and at 3500 g the bearing holds about 162.9 kN of C0 per kilogram. Machined-cage order-number note: the M brass cage is a one-piece ball-centred window cage, chosen at the heavy end of the section for speed and shock duty; it is heavier and stiffer than the pressed-steel execution of the smaller sizes and tolerates interrupted lubrication far better, which is why the catalogue restricts the M suffix to the large bores. At 3500 g the machined brass cage represents a meaningful fraction of total mass; balancing checks on high-speed 180 mm vertical shafts should use the actual M-execution weight, not the lighter pressed-cage catalogue value.

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 51136 against two-way load lifts the loose washer off its raceway.
• The third digit grades the section: 511 light, then 512, 513 and 514 progressively taller and heavier at the same bore — select from 135/570 kN and the available 225 mm OD, never substitute a lighter series for a heavier one without rechecking C and C0.
• 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 34 mm stack; thrust-ball bearings on horizontal shafts should have the shaft washer (the tight one) against the rotating element.
• 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 135 kN track before first rotation.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 51136 M as the single flat brass execution; other order numbers of the 51136 size are different products and may carry different ratings or seating geometry — always quote the full designation when purchasing.