53208 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 53208 model number is decoded

53208 is SKF's 40 mm-bore single-direction thrust ball bearing in the 53200 series to the ISO 104 dimension plan, with a sphered housing washer paired to a U seat washer, measuring 40×68×20.3 mm U 208 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 40×68×20.3 mm (1.575×2.677×0.799 in), 14.0 mm radial section, C 44.2 kN, C0 96.5 kN, Pu 3.6 kN. Mounted height H1 23 mm includes the U 208 seat washer; the bearing alone is 20.3 mm high. reference speed 3,600 r/min (thermal) and limiting speed 5,300 r/min (mechanical), catalogue mass 350 g. Capacity density: 44.2 kN C from 0.350 kg of bearing steel gives about 126.3 kN per kilogram; static density is correspondingly 275.7 kN/kg at C0 96.5 kN. At the printed limiting speed of 5,300 r/min the mean pitch diameter dm ≈ 54.0 mm implies a dn value around 286k mm·r/min; the 3,600 r/min reference speed is the thermal-planning value under catalogue load. Load balance: C0 96.5 kN against C 44.2 kN gives a 2.18 ratio — thrust ball bearings are chosen on static rating and F_a/C0 far more often than on L10 life, while Pu 3.6 kN enters the adjusted-life check. Preload at the mechanical ceiling: repeating Fam ≈ A·(n·dm/1000)² with factor A 0.058 at the 5,300 r/min limiting speed raises the required axial preload to about 4.8 kN; the reference-speed value 2.2 kN is the thermal design point. Static-first selection data: 96.5 kN C0 spread across the 20.3 mm stack gives 4.8 kN of static rating per height millimetre, and the 350 g mass/C0 ratio is about 4 g per static kN — crane-hook and screw positions are normally sized on these two 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. The aligning angle is set by how far the sphered back of the 68 mm washer can tilt inside the U 208 seat; check the actual tilt allowance in the mounting drawing, since the 2.7 mm washer thickness step does not by itself quantify it.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• The self-aligning feature is checked at commissioning by hand: with the shaft under no load the assembly must swivel and settle; a stiff spherical seat means dirt, a mismatched U washer, or a register bored off-axis.
• Replacement orders must list both 53208 and U 208: the seat washer is a separate article, and a U washer of the wrong size narrows the contact band of the 96.5 kN static-rated set.
• Minimum axial load still applies with factor A 0.058: a self-aligning seat does not prevent ball skidding, so provide spring preload or sufficient rotor weight at light load and speed.
• The shaft washer remains the tight, ground-bore component on the 40 mm shaft; the sphered part is the HOUSING washer, and the U seat washer is the loose flat-backed part — the fitting order is shaft washer and cage set first, then housing washer and U 208 into the register.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 53208 as the single sphered pressed steel execution; other order numbers of the 53208 size are different products and may carry different ratings or seating geometry — always quote the full designation including the U 208 seat washer when purchasing.