39581-39528 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB) · extracted 2026-09-28

Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB); 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 39581-39528 model number is decoded

Reading the designation: 39581 follows the Timken-style inch convention — the cone (inner ring with rollers) and cup (outer ring) are quoted as a pair separated by a slash, and the 39500-series code identifies the dimensional series. The 53.975 mm bore, 119.985 mm OD and 32.751 mm width are the metric equivalents of the inch boundary dimensions. SKF lists the plain number as the basic execution; letter suffixes such as B denote a steeper contact angle and are different order numbers. At 4,500 r/min reference speed the 33.0 mm-section 39581 is governed thermally by preload and lubricant flow; grease or oil selection should be made against that value, with 5,600 r/min as the mechanical ceiling. Because the contact line is tapered, one 39581 reacts thrust in a single direction; bidirectional shafts need an O or X pair, and a rotating cone on a 53.975 mm shaft typically takes a k5 seat with an H7 housing bore. Speed envelope and thermal behaviour: at 4,500 r/min thermal reference, the 53.975 mm bore shaft runs at a dn of 243k, and the 33.0 mm section dissipates heat through the cup-to-housing contact path; the 5,600 r/min mechanical ceiling reflects cage strength, and the 1750 g spinning cone contributes gyroscopic moment under rapid speed reversal. From a specification standpoint the 39528 cup is the controlling half of 39581 for housing design — it sets the 119.985 mm OD and the outer abutment diameter — while the 39581 cone controls shaft fit at the 53.975 mm bore; the 32.751 mm width is the result of the two together.39581 is a single-row tapered roller bearing in the 39500-series inch series: a separable cone-and-cup design for combined radial and one-direction axial load, listed by SKF in SKF catalogue PUB BU/P1 17000.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On this 53.975 mm bore, interference and temperature rise consume clearance inside a preloaded pair; calculate the residual clearance after mounting and at operating temperature — an over-tight 39581 pair heats, loses setting control and smears the roller-rib contact.
• The 320 series at 53.975 mm bore (119.985×32.751 mm) is the low-friction, higher-speed section; it carries less thrust than a 302 of the same bore, so verify the axial load share before swapping.
• When the outer ring rotates, reverse the fit logic and provide cup location; the tapered contact of 39581 pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
• O (back-to-back) pairs are stiffer against moments, X (face-to-face) pairs tolerate misalignment and thermal growth better; choosing the arrangement from the 2D drawing rather than the actual shaft thermal expansion is a common 39581 mounting error.
• The pressed-steel cage is rated for standard industrial service; sustained running above the limiting speed or with degraded lubricant wears the cage pockets — inspect the cage at every relubrication interval.
• The 175/204 kN ratings are SKF catalogue 17000 values for the basic execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
• SKF lists several executions of 39581 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 39581/39528 designation when purchasing and match the execution to the mounting arrangement.