18590-18520 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 18590-18520 model number is decoded

Operating context for the 41.275 mm bore: a shaft of this diameter in the medium-bore band typically runs between 33020 and 49530 r/min in real machinery, and the 73.025 mm outside diameter places the housing shoulder at 81 mm outer abutment; the 16.667 mm width and 280 g mass together set the shaft critical speed and the housing resonance check for this 18500-series envelope. Cone-and-cup identity in 18590: the leading 18590 reference identifies the inner ring, rollers and cage; the trailing 18520 reference identifies the outer ring. The 18500-series series lists alternative cups for the same cone, each producing a different 73.025 mm OD or 16.667 mm width — hence a different SKU even though the bore stays at 41.275 mm.The SKF 18590/18520 is a 41.275×73.025×16.667 mm single-row tapered roller bearing — an inch-series entry with an asymmetric raceway cut for thrust capacity and separable mounting.Numbering ties the bearing to its inch-series envelope: 18590 means a cone and cup matched pair in the 18500-series series — which is why the 41.275×73.025×16.667 mm outline swaps dimensionally with other inch-series bearings of the same code. In SKF suffix language a bare 18590 is the standard execution; B marks a larger contact angle and Q or J2 mark clearance/cage variants, all quoted separately. The 15.9 mm radial section height ((73.025−41.275)/2) and 280 g catalogue mass frame a 41.275 mm bore bearing rated at 57.7 kN C — roughly 1.40 kN of dynamic capacity per millimetre of bore before application factors. A single 18590 locates the shaft in one axial direction only; mount it against a second bearing in O (back-to-back) or X (face-to-face) arrangement, and set the running clearance by the mounting procedure — not by feel.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On this 41.275 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 18590 pair heats, loses setting control and smears the roller-rib contact.
• The 18500-series inch series at 41.275 mm bore (73.025×16.667 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.
• Do not mix brands or executions inside one 18590 pair — matched sets are ground for a specific setting, and pairing a SKF basic unit with a different suffix variant will not share the setting evenly.
• Do not mix brands or executions inside one 18590 pair — matched sets are ground for a specific setting, and pairing a SKF basic unit with a different suffix variant will not share the setting evenly.
• Catalogue reference speed and limiting speed are different limits: the 7,500 r/min reference is a thermal criterion under load, while the 9,000 r/min limiting value is the mechanical ceiling — observe both.
• The 57.7/56 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 18590 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 18590/18520 designation when purchasing and match the execution to the mounting arrangement.