387A-382S 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 387A-382S model number is decoded

Cone-and-cup identity in 387A: the leading 387 A reference identifies the inner ring, rollers and cage; the trailing 382 S reference identifies the outer ring. The 385-series series lists alternative cups for the same cone, each producing a different 96.838 mm OD or 25.4 mm width — hence a different SKU even though the bore stays at 53.975 mm.387A is a single-row tapered roller bearing in the 385-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.Digit by digit, 387A reads as cone reference / cup reference in the 385-series inch series; the 53.975 mm bore, 96.838 mm OD and 25.4 mm width are the metric equivalents of the original inch boundary values. The SKF catalogue adds the ISO 355 dimension-series code after the bare number (e.g. ); it is the dimensional series, not a separate part number. Selection arithmetic: the C0/C ratio is about 1.02 (static 102 kN against dynamic 99.9 kN), typical of a tapered roller sized for axial capacity, and the 11.6 kN fatigue load limit Pu is the equivalent-load floor used in the life calculation. Fit selection follows the rotating ring — interference on a rotating cone — and two 387A units are required to take reversing thrust; keep the induced axial load inside the rated capacity when calculating the pair. Cross-section geometry: the 21.4 mm half-section ((96.838−53.975)/2) of this 38700-series unit places the roller large-end pitch diameter at roughly 75 mm, and the 25.4 mm axial width is split between cone (14 mm) and cup rib (11 mm) — a geometry that sets the contact angle and, with the 650 g rotating cone mass, the critical speed at which cage-roller imbalance begins.

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 387A pair heats, loses setting control and smears the roller-rib contact.
• The 320 series at 53.975 mm bore (96.838×25.4 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 387A pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
• When the outer ring rotates, reverse the fit logic and provide cup location; the tapered contact of 387A pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
• The 387A shares its ISO 355 envelope with other tapered bearings of the same code but is not a drop-in replacement for a ball bearing: it cannot run effectively under pure radial load without a minimum axial load, and a deep-groove bearing cannot replace its combined-load duty.
• The 99.9/102 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 387A (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 387 A/382 S designation when purchasing and match the execution to the mounting arrangement.