47678-47620 bearing: complete specifications & equivalents
The 47678-47620 is a ISO 355 radial bearing sized 76.2 x 133.35 x 33.338 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 76.2 mm |
| Outer diameter D | 133.35 mm |
| Width B | 33.338 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 202 kN |
| Basic static load rating C0 | 260 kN |
| Fatigue load limit Pu | 30 kN |
| Reference speed (thermal) | 3800 rpm |
| Limiting speed (mechanical) | 4800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1950 g |
| Manufacturer designation | SKF 47678/47620 |
| 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 & 47600-series range
| Bore d | 3 in |
|---|---|
| Outer diameter D | 5.25 in |
| Width B | 1.313 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 28.6 mm |
| Smallest bore in 47600-series | 76.2 mm |
| Largest outer diameter in 47600-series | 133.35 mm |
| Width range across 47600-series | 33.338–33.338 mm |
| Bore position in 47600-series (smallest first) | 1 of 1 |
| Bore above smallest 47600-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 47678-47620-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 76.2×133.35×33.338 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 47678-47620 | 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 47678-47620 model number is decoded
With C 202 kN and C0 260 kN, the 47678 pair-sizing check is dominated by the axial share: keep the equivalent load P below the rating at the required L10, remembering one bearing alone cannot cover reversing thrust at 4,800 r/min. Note the minimum-axial-load requirement: at light radial load and high speed the rollers of 47678 must still be held into the rib contact, which is another reason the catalogue recommends paired mounting with controlled setting. Speed envelope and thermal behaviour: at 3,800 r/min thermal reference, the 76.2 mm bore shaft runs at a dn of 290k, and the 28.6 mm section dissipates heat through the cup-to-housing contact path; the 4,800 r/min mechanical ceiling reflects cage strength, and the 1950 g spinning cone contributes gyroscopic moment under rapid speed reversal. Cone versus cup responsibility in 47678: the 47678 cone carries the 76.2 mm bore, rollers and pressed-steel cage; the 47620 cup carries the 133.35 mm OD raceway, the roller-seating rib and the outer press-fit surface. The two references are not interchangeable halves.Ordering number SKF 47678/47620 in SKF catalogue PUB BU/P1 17000 denotes a single-row tapered roller bearing for a 76.2 mm shaft, inch series, with an open pressed-steel-cage execution and one-direction axial capacity.Digit by digit, 47678 reads as cone reference / cup reference in the 47600-series inch series; the 76.2 mm bore, 133.35 mm OD and 33.338 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.
Typical equipment & failure modes
Common applications
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
- rolling-mill auxiliary drives
- 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
- rib-roller contact scoring from loss of the EP additive film
Selection pitfalls — read before you substitute
- Mount the 76.2 mm bore 47678 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 47600-series inch series at 76.2 mm bore (133.35×33.338 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.
- 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 47678 mounting error.
- Setting is a design value, not an assembly feel: excessive preload in the 47678 pair raises operating temperature and can trigger thermal runaway, while too little lets the rollers skid and smear the raceway under light load.
- The pressed-steel cage is rated for standard industrial service; sustained running above the limiting speed or with degraded lubricant wears the cage pockets — inspect the cage at every relubrication interval.
- The 202/260 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 47678 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 47678/47620 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
Can a single 47678 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 47678 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 47678 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
What shaft and housing fits suit 47678?
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 33.338 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 47678 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 47678?
The SKF 47678/47620 is a single-row tapered roller bearing with 76.2 mm bore, 133.35 mm outer diameter and 33.338 mm width (3 × 5.25 × 1.313 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 202 kN, C0 260 kN, fatigue load limit Pu 30 kN, reference speed 3,800 r/min, limiting speed 4,800 r/min, mass about 1950 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.