51322-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 51322-M model number is decoded

51322 M is SKF's 110 mm-bore single-direction thrust ball bearing in the 51300 series to the ISO 104 dimension plan, with a flat housing seating surface, measuring 110×190×63 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 22 encode the bore as 110 mm (code 22 × 5), the standard SKF bore-code rule shared with radial bearings. suffix M identifies a one-piece machined brass cage, ball-centred: the large-size and heavy-section option for higher speeds, shock loads and thin-film lubrication where a pressed cage would distort. Envelope 110×190×63 mm (4.331×7.48×2.48 in), 40.0 mm radial section, C 281 kN, C0 815 kN, Pu 24.5 kN. reference speed 1,200 r/min (thermal) and limiting speed 1,700 r/min (mechanical), catalogue mass 7850 g. Pitch-diameter arithmetic: dm = (110+190)/2 = 150.0 mm; at the 1,700 r/min limiting speed that corresponds to roughly 255k mm·r/min, the figure used when comparing cage speed demand across the thrust-ball series. Washer-annulus check: the π/4·(D²−d²) contact annulus of 51322 M covers about 18,850 mm², distributing C0 815 kN over a mean track circle of π·dm ≈ 471 mm. Sizing arithmetic on the 110 mm bore: 281 kN C over the 40.0 mm radial section gives 7.0 kN per section millimetre, and the 63 mm stack height is 1.57× that section — proportions typical of a 51300 thrust section. Preload at the mechanical ceiling: repeating Fam ≈ A·(n·dm/1000)² with factor A 3.2 at the 1,700 r/min limiting speed raises the required axial preload to about 208.1 kN; the reference-speed value 103.7 kN is the thermal design point. Section proportions: the 40.0 mm radial section compares with 110 mm of bore (section/bore ≈ 0.36) and the 63 mm height is 1.57× that section — the proportions that identify the 51300 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. At 7850 g the machined brass cage represents a meaningful fraction of total mass; balancing checks on high-speed 110 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

• The 51322 M is a pure axial bearing: it must never be subjected to radial load — any radial force on the 110 mm shaft has to be carried by a radial bearing mounted alongside it.
• When the housing seat cannot be machined square to the 110 mm shaft, the sphered 53-series execution of this size with its U seat washer is the self-aligning counterpart of this flat 51300 bearing.
• Identify the washers before fitting: the shaft washer has the ground, smaller bore and takes an interference fit on the 110 mm shaft, while the housing washer bore is larger and runs loose; swapping them locks the ball set and burns the tracks.
• 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 281 kN track before first rotation.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 51322 M as the single flat brass execution; other order numbers of the 51322 size are different products and may carry different ratings or seating geometry — always quote the full designation when purchasing.