387-382A bearing: complete specifications & equivalents
The 387-382A is a ISO 355 radial bearing sized 53.975 x 96.838 x 21 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 53.975 mm |
| Outer diameter D | 96.838 mm |
| Width B | 21 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 99.9 kN |
| Basic static load rating C0 | 102 kN |
| Fatigue load limit Pu | 11.6 kN |
| Reference speed (thermal) | 5600 rpm |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 590 g |
| Manufacturer designation | SKF 387/382 A |
| Standard | ISO 355 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB |
| Last verified | 2026-09-28 |
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.
Dimensions in inches & 385-series range
| Bore d | 2.125 in |
|---|---|
| Outer diameter D | 3.813 in |
| Width B | 0.827 in |
| ISO bore code | 87 |
| Radial section height (D−d)/2 | 21.4 mm |
| Smallest bore in 385-series | 53.975 mm |
| Largest outer diameter in 385-series | 98.425 mm |
| Width range across 385-series | 21–25.4 mm |
| Bore position in 385-series (smallest first) | 1 of 1 |
| Bore above smallest 385-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 387-382A-NTN | NTN | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue. |
| 387-382A | Timken | full Dimensions and internal design equivalent — standard interchange. | Same inch-series cone/cup boundary envelope (d/D/T); load ratings and speed limits are brand-specific and may differ. |
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 387-382A model number is decoded
The 21.4 mm radial section height ((96.838−53.975)/2) and 590 g catalogue mass frame a 53.975 mm bore bearing rated at 99.9 kN C — roughly 1.85 kN of dynamic capacity per millimetre of bore before application factors. Specify pairs rather than single units wherever thrust reverses: the tapered contact of 387 generates an induced axial load under radial force, and an unpaired bearing on a reversing shaft will run slack and fret its seat. Speed envelope and thermal behaviour: at 5,600 r/min thermal reference, the 53.975 mm bore shaft runs at a dn of 302k, and the 21.4 mm section dissipates heat through the cup-to-housing contact path; the 6,700 r/min mechanical ceiling reflects cage strength, and the 590 g spinning cone contributes gyroscopic moment under rapid speed reversal. A single-row inch tapered bearing is quoted as a cone/cup pair because the boundary dimensions belong to the combination, not to either half alone: in 387 the 387 cone contributes the 53.975 mm bore and roller set, the 382 A cup contributes the 96.838 mm OD raceway, and the assembled 21 mm width is the catalogue value.The SKF 387/382 A is a 53.975×96.838×21 mm single-row tapered roller bearing — an inch-series entry with an asymmetric raceway cut for thrust capacity and separable mounting.The 385-series series assigns 53.975 mm bore, 96.838 mm OD and 21 mm width to 387; the cone and cup references are not interchangeable with other inch-series pairs even when the bore matches, because the cup profile and rib geometry are series-specific. SKF lists the plain number as the basic execution; letter suffixes such as B denote a steeper contact angle and are different order numbers.
Typical equipment & failure modes
Common applications
- axle-boxes in material-handling equipment
- automotive and light-truck wheel hubs
- industrial gearbox shafts and reducers
- belt-driven fan and blower shafts
Known failure patterns
- cup or cone misalignment when the separable rings are not seated square during mounting
- loose cup rotation in the housing when the specified press fit is not achieved
- axial overload spalling at the roller-rib contact beyond the single-row thrust rating
- preload loss as the mounted pair relaxes, letting rollers skid and smear the raceways
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- rolling-contact fatigue spalling after the rated L10 life is exceeded
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 387 pair heats, loses setting control and smears the roller-rib contact.
- The 320 series at 53.975 mm bore (96.838×21 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.
- Setting is a design value, not an assembly feel: excessive preload in the 387 pair raises operating temperature and can trigger thermal runaway, while too little lets the rollers skid and smear the raceway under light load.
- 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 387 mounting error.
- Never press both rings through the wrong element during fitting: force for an interference shaft seat goes through the cone only, or brinell marks on the 96.838 mm cup race release as noise within the first running hours.
- 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 387 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 387/382 A designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
Can a single 387 take axial load in both directions?
No — one single-row tapered roller bearing reacts thrust in one direction only, and under radial load its contact angle induces an axial force. Use two bearings as a matched pair: O (back-to-back) for a rigid, moment-resisting arrangement, X (face-to-face) where thermal expansion must be tolerated, or tandem where one-direction thrust is shared.
How does 387 compare with a ball bearing of the same bore?
A tapered roller bearing has line contact and a steep contact angle: much higher combined axial-plus-radial capacity and shock resistance than a ball bearing of the same bore, at the cost of speed, one-direction thrust, mandatory pairing for reversing loads and a minimum axial load requirement. A ball bearing cannot be dropped into a combined-load 387 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
What shaft and housing fits suit 387?
For a rotating shaft under normal load, seat the cone on a k5 shaft fit; the cup is usually a loose-to-transition fit in the housing so it can creep slightly and distribute wear. Chamfer and shoulder diameters must clear the bearing rings so the 21 mm-wide cup seats square; the mounting setting (end play or preload) is set by the axial position of the cup relative to the cone.
Is 387 interchangeable with other brands?
Inch-series tapered roller bearings follow a long-standing industry boundary plan, so cones and cups of the same basic number are generally dimensionally interchangeable across manufacturers. However, internal geometry, cage design and load ratings differ by brand, so for paired or precision applications keep both halves of the set from one manufacturer — or re-verify ratings and setting when mixing.
What are the dimensions and catalogue data of 387?
The SKF 387/382 A is a single-row tapered roller bearing with 53.975 mm bore, 96.838 mm outer diameter and 21 mm width (2.125 × 3.813 × 0.827 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 99.9 kN, C0 102 kN, fatigue load limit Pu 11.6 kN, reference speed 5,600 r/min, limiting speed 6,700 r/min, mass about 590 g. It is an open, separable bearing with a pressed-steel cage.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB on 2026-09-28. Read our editorial & correction policy.