51430-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 51430-M model number is decoded

The 51400 series order number 51430 M is a SKF single-direction thrust ball bearing for a 150 mm seat, built to ISO 104, with a flat housing seating surface, 150×300×120 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 30 decodes to 150 mm (code 30 × 5) under the same 00/01/02/03-exception, ×5 rule SKF uses across its coded bearing ranges. the trailing M names a solid machined brass window cage centred on the balls rather than on a washer, the catalogue choice when size, speed or interrupted lubrication rules out sheet steel. Envelope 150×300×120 mm (5.906×11.811×4.724 in), 75.0 mm radial section, C 559 kN, C0 1960 kN, Pu 48 kN. reference speed 670 r/min (thermal) and limiting speed 950 r/min (mechanical), catalogue mass 42500 g. Envelope economics: the 120 mm axial height over a 75.0 mm radial section yields 4.7 kN of dynamic capacity per height millimetre, and the bearing weighs 42500 g for 559 kN C — about 76 g per rated kN. Selection figures for 51430 M: the C0/C ratio is 3.51, Pu 48 kN is about 9 % of C, and the catalogue mass works out to roughly 283 g per millimetre of bore; the printed minimum-load factor is A 20. Washer-annulus check: the π/4·(D²−d²) contact annulus of 51430 M covers about 53,014 mm², distributing C0 1960 kN over a mean track circle of π·dm ≈ 707 mm. Speed band width for this size is 280 r/min between reference and limiting (1.42× ratio); lubrication, preload and heat removal decide where inside that band 51430 M can actually run. Section proportions: the 75.0 mm radial section compares with 150 mm of bore (section/bore ≈ 0.50) and the 120 mm height is 1.60× that section — the proportions that identify the 51400 envelope at a glance. 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. The M cage of 51430 M adds a small amount of mass and cage strength without changing the 150×300×120 mm ISO 104 envelope, so the pressed-cage execution drops into the same recess but should not be assumed equal under the 950 r/min ceiling.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Identify the washers before fitting: the shaft washer has the ground, smaller bore and takes an interference fit on the 150 mm shaft, while the housing washer bore is larger and runs loose; swapping them locks the ball set and burns the tracks.
• 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.
• Keep the applied thrust above Fam ≈ A·(n·dm/1000)² with the printed factor A 20; for 51430 M 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.
• When the housing seat cannot be machined square to the 150 mm shaft, the sphered 53-series execution of this size with its U seat washer is the self-aligning counterpart of this flat 51400 bearing.
• The 559/1960 kN figures belong to 51430 M specifically (the single flat brass execution of 51430); suffixed, sphered and counterpart-series order numbers are separate articles, so write the complete designation on the order and the maintenance record.