15578-15520 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 15578-15520 model number is decoded

Cross-section geometry: the 15.9 mm half-section ((57.15−25.4)/2) of this 15500-series unit places the roller large-end pitch diameter at roughly 41 mm, and the 17.462 mm axial width is split between cone (10 mm) and cup rib (8 mm) — a geometry that sets the contact angle and, with the 220 g rotating cone mass, the critical speed at which cage-roller imbalance begins. Inch tapered bearings are matched sets, not mix-and-match components: 15578 pairs the 15578 cone with the 15520 cup under the 15500-series boundary plan, and although the same cone shows up against other cups in the catalogue, each pairing yields a distinct assembled width and a distinct rating row.In SKF catalogue PUB BU/P1 17000, 15578 appears as SKF 15578/15520: an open, single-row tapered roller bearing in the 15500-series, supplied with a pressed-steel cage as standard.In SKF inch-series tables 15578 sits at 25.4 mm bore (1 in) with a 57.15 mm cup OD and 17.462 mm total width — dimensions that trace back to the original Timken boundary plan for the 15500-series family. SKF lists the plain number as the basic execution; letter suffixes such as B denote a steeper contact angle and are different order numbers. Catalogue mass 220 g for the 25.4×57.15×17.462 mm open execution covers the pressed-steel cage and standard roller complement; sealed or special-clearance variants differ slightly in mass and carry their own order numbers. Specify pairs rather than single units wherever thrust reverses: the tapered contact of 15578 generates an induced axial load under radial force, and an unpaired bearing on a reversing shaft will run slack and fret its seat.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On this 25.4 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 15578 pair heats, loses setting control and smears the roller-rib contact.
• The 15500-series inch series at 25.4 mm bore (57.15×17.462 mm) follows the Timken cone/cup convention; substitutions must match both the cone and cup reference exactly — interchanging with another series or a metric 3xxxx bearing of the same bore changes OD, width and contact angle, so re-run the pair setting and shoulder-diameter checks before swapping.
• When the outer ring rotates, reverse the fit logic and provide cup location; the tapered contact of 15578 pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
• At the 49.1 kN rating of 15578, preload class changes stiffness by tens of percent but also heat generation; select light preload for the 12,000 r/min speed end and heavier preload only where moment stiffness dominates.
• The 220 g mass and 17.462 mm width mean spacer and abutment faces must be square to the axis within the bearing's own P0 tolerance; a tilted spacer tilts the contact angle and concentrates load on one rib of 15578.
• The 49.1/45.5 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 15578 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 15578/15520 designation when purchasing and match the execution to the mounting arrangement.