3982-3920 bearing: complete specifications & equivalents
The 3982-3920 is a ISO 355 radial bearing sized 63.5 x 112.712 x 30.163 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 63.5 mm |
| Outer diameter D | 112.712 mm |
| Width B | 30.163 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 152 kN |
| Basic static load rating C0 | 183 kN |
| Fatigue load limit Pu | 21.2 kN |
| Reference speed (thermal) | 4800 rpm |
| Limiting speed (mechanical) | 5600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1250 g |
| Manufacturer designation | SKF 3982/3920 |
| 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 & 3980-series range
| Bore d | 2.5 in |
|---|---|
| Outer diameter D | 4.437 in |
| Width B | 1.188 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 24.6 mm |
| Smallest bore in 3980-series | 63.5 mm |
| Largest outer diameter in 3980-series | 112.712 mm |
| Width range across 3980-series | 30.163–30.163 mm |
| Bore position in 3980-series (smallest first) | 1 of 1 |
| Bore above smallest 3980-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 3982-3920-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 63.5×112.712×30.163 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 3982-3920 | 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 3982-3920 model number is decoded
SKF 3982 (SKF 3982/3920) is the 3980-series tapered roller choice for a 63.5 mm shaft — one row of tapered rollers on an asymmetric raceway inside the 112.712×30.163 mm envelope.Digit by digit, 3982 reads as cone reference / cup reference in the 3980-series inch series; the 63.5 mm bore, 112.712 mm OD and 30.163 mm width are the metric equivalents of the original inch boundary values. 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 4,800 r/min reference speed the 24.6 mm-section 3982 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 3982 reacts thrust in a single direction; bidirectional shafts need an O or X pair, and a rotating cone on a 63.5 mm shaft typically takes a k5 seat with an H7 housing bore. Dimensional interchange map: within the 39800 series at 63.5 mm bore, the 112.712 mm OD and 30.163 mm width are fixed by the ISO 355 plan, so any same-code bearing from another brand shares the mounting envelope; the 24.6 mm section height distinguishes this family from a 302 or 322 of the same bore, and the 1250 g mass is the minimum—sealed or snap-ring executions add rotating weight above that catalogue baseline. 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 3982 the 3982 cone contributes the 63.5 mm bore and roller set, the 3920 cup contributes the 112.712 mm OD raceway, and the assembled 30.163 mm width is the catalogue value.
Typical equipment & failure modes
Common applications
- marine deck machinery shafts
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
- marine deck machinery 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
- roller large-end smearing against the cone rib after EP lubricant film failure
- axial overload spalling at the roller-rib contact beyond the single-row thrust rating
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- electrical pitting on VFD-driven shafts without grounding protection
Selection pitfalls — read before you substitute
- Mount the 63.5 mm bore 3982 by induction heating of the cone (max 120 °C — the pressed-steel cage sets the ceiling, not the steel); driving it home through the cup or rollers brinells the tapered raceway.
- The 320 series at 63.5 mm bore (112.712×30.163 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 3982 pair raises operating temperature and can trigger thermal runaway, while too little lets the rollers skid and smear the raceway under light load.
- Do not mix brands or executions inside one 3982 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.
- Open 3982 units need application-supplied sealing and a defined EP lubricant supply; the roller-rib contact is the first to fail when the additive film breaks down.
- The 152/183 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 3982 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 3982/3920 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 3982?
The SKF 3982/3920 is a single-row tapered roller bearing with 63.5 mm bore, 112.712 mm outer diameter and 30.163 mm width (2.5 × 4.437 × 1.188 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 152 kN, C0 183 kN, fatigue load limit Pu 21.2 kN, reference speed 4,800 r/min, limiting speed 5,600 r/min, mass about 1250 g. It is an open, separable bearing with a pressed-steel cage.
How does the 3982 inch-series designation work?
Inch-series tapered roller bearings use a Timken-style cone/cup convention: the number before the slash identifies the cone (inner ring with roller and cage assembly), the number after the slash identifies the cup (outer ring), and the 3980-series code marks the dimensional series. The metric dimensions 63.5×112.712×30.163 mm are the converted equivalents of the original inch boundary dimensions.
What do the cone and cup numbers in 3982 mean?
The cone number (before the slash) identifies the inner ring, rollers and cage; the cup number (after the slash) identifies the outer ring. Both are quoted together because a single-row tapered roller bearing is a matched separable pair — the cone and cup are ground to work together and are not interchangeable with arbitrary other parts. The series prefix (3980-series) groups sizes that share the same boundary-dimension plan.
Can a single 3982 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 3982 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 3982 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
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.