53408 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 53408 model number is decoded

53408 is SKF's 40 mm-bore single-direction thrust ball bearing in the 53400 series to the ISO 104 dimension plan, with a sphered housing washer paired to a U seat washer, measuring 40×90×38.2 mm U 408 seat washer companion included in the mounted H1 dimension. 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 53xxx designation the 3 marks a single-direction bearing whose housing washer has a sphered (convex) seating surface, intended to run against the matching U seat washer; the third digit 2–4 grades the section. the final two digits 08 encode the bore as 40 mm (code 08 × 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 40×90×38.2 mm (1.575×3.543×1.504 in), 25.0 mm radial section, C 95.6 kN, C0 183 kN, Pu 6.8 kN. Mounted height H1 42 mm includes the U 408 seat washer; the bearing alone is 38.2 mm high. reference speed 2,400 r/min (thermal) and limiting speed 3,200 r/min (mechanical), catalogue mass 1350 g. Imperial cross-check for procurement drawings: 1.575 in bore, 3.543 in OD, 1.504 in height, and the 1350 g catalogue mass converts to 1.350 kg (47.6 oz). Envelope economics: the 38.2 mm axial height over a 25.0 mm radial section yields 2.5 kN of dynamic capacity per height millimetre, and the bearing weighs 1350 g for 95.6 kN C — about 14 g per rated kN. Sizing arithmetic on the 40 mm bore: 95.6 kN C over the 25.0 mm radial section gives 3.8 kN per section millimetre, and the 38.2 mm stack height is 1.53× that section — proportions typical of a 53400 thrust section. Selection figures for 53408: the C0/C ratio is 1.91, Pu 6.8 kN is about 7 % of C, and the catalogue mass works out to roughly 34 g per millimetre of bore; the printed minimum-load factor is A 0.26. Mass and section check: 1350 g inside the 40×90×38.2 mm outline leaves a 25.0 mm radial section, and the 183 kN static rating is 1.91× the dynamic rating — plan static safety and minimum preload against those figures. Sphered-seating order-number note: the convex back face of the housing washer is finish-ground spherical and is delivered to mate with the separately ordered U seat washer, which presents a flat face to the housing and a concave face to the washer; together they accommodate initial static misalignment, but the pair must be kept clean, greased at the spherical interface and never replaced by a washer-on-flat-steel makeshift. Procurement reminder for this specific page: 53408 and U 408 are two order numbers shipping as two articles; the installed 42 mm H1 rather than 38.2 mm H is the dimension the housing drawing must carry.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• The sphered housing washer of 53408 MUST run against the U 408 seat washer, a separate order number; mounted bare on a flat register, the convex back makes point contact that gouges the housing under load.
• Keep the sphered interface clean and lightly greased: scale, paint or grit between the washer back and U 408 locks the aligning function and frets under load; re-grease the contact at every overhaul.
• Dimension the housing to the 42 mm mounted height H1 (bearing plus U 408), not the 38.2 mm bearing height H — confusing the two is a recurring drawing error for the 53-series.
• The spherical seat accommodates INITIAL static misalignment between shaft and housing; it is not a swivel for continuous oscillation, and the bearing still carries pure axial load with no radial capacity.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 53408 as the single sphered pressed steel execution; other order numbers of the 53408 size are different products and may carry different ratings or seating geometry — always quote the full designation including the U 408 seat washer when purchasing.