53320 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 53320 model number is decoded

53320 is SKF's 100 mm-bore single-direction thrust ball bearing in the 53300 series to the ISO 104 dimension plan, with a sphered housing washer paired to a U seat washer, measuring 100×170×59.2 mm U 320 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 20 encode the bore as 100 mm (code 20 × 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 100×170×59.2 mm (3.937×6.693×2.331 in), 35.0 mm radial section, C 225 kN, C0 570 kN, Pu 18.3 kN. Mounted height H1 64 mm includes the U 320 seat washer; the bearing alone is 59.2 mm high. reference speed 1,300 r/min (thermal) and limiting speed 1,800 r/min (mechanical), catalogue mass 5950 g. Speed planning separates the two ceilings mechanically: the pressed cage and balls tolerate 1,800 r/min while thermal balance under catalogue load sets the 1,300 r/min reference; at dm ≈ 135.0 mm the corresponding dn is approximately 243k mm·r/min. Mass and section check: 5950 g inside the 100×170×59.2 mm outline leaves a 35.0 mm radial section, and the 570 kN static rating is 2.53× the dynamic rating — plan static safety and minimum preload against those figures. Rating split for documentation: dynamic 225 kN (L10 life), static 570 kN (safety factor s0), fatigue limit 18.3 kN (adjusted life) — three different uses of three different numbers for 53320, none interchangeable with another. Preload at the mechanical ceiling: repeating Fam ≈ A·(n·dm/1000)² with factor A 1.9 at the 1,800 r/min limiting speed raises the required axial preload to about 112.2 kN; the reference-speed value 58.5 kN is the thermal design point. Capacity density: 225 kN C from 5.950 kg of bearing steel gives about 37.8 kN per kilogram; static density is correspondingly 95.8 kN/kg at C0 570 kN. 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 170 mm washer can tilt inside the U 320 seat; check the actual tilt allowance in the mounting drawing, since the 4.8 mm washer thickness step does not by itself quantify it.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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.
• The shaft washer remains the tight, ground-bore component on the 100 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 320 into the register.
• The sphered housing washer of 53320 MUST run against the U 320 seat washer, a separate order number; mounted bare on a flat register, the convex back makes point contact that gouges the housing under load.
• Replacement orders must list both 53320 and U 320: the seat washer is a separate article, and a U washer of the wrong size narrows the contact band of the 570 kN static-rated set.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 53320 as the single sphered pressed steel execution; other order numbers of the 53320 size are different products and may carry different ratings or seating geometry — always quote the full designation including the U 320 seat washer when purchasing.