33281-33462 bearing: complete specifications & equivalents
The 33281-33462 is a ISO 355 radial bearing sized 71.438 x 117.475 x 30.162 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 71.438 mm |
| Outer diameter D | 117.475 mm |
| Width B | 30.162 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 | 190 kN |
| Fatigue load limit Pu | 21.6 kN |
| Reference speed (thermal) | 4500 rpm |
| Limiting speed (mechanical) | 5300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1250 g |
| Manufacturer designation | SKF 33281/33462 |
| 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 & 33000-series range
| Bore d | 2.813 in |
|---|---|
| Outer diameter D | 4.625 in |
| Width B | 1.187 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 23 mm |
| Smallest bore in 33000-series | 25 mm |
| Largest outer diameter in 33000-series | 225 mm |
| Width range across 33000-series | 17–59 mm |
| Bore position in 33000-series (smallest first) | 11 of 24 |
| Bore above smallest 33000-series size | 46.438 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33281-33462-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 71.438×117.475×30.162 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 33281-33462 | 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 33281-33462 model number is decoded
On the SKF nameplate, 33281 denotes a matched cone-and-cup pair: the designation is not a single number but a cone reference and cup reference joined by a slash, with the 33000-series marking the dimensional series. In SKF suffix language a bare 33281 is the standard execution; B marks a larger contact angle and Q or J2 mark clearance/cage variants, all quoted separately. The 23.0 mm radial section height ((117.475−71.438)/2) and 1250 g catalogue mass frame a 71.438 mm bore bearing rated at 152 kN C — roughly 2.13 kN of dynamic capacity per millimetre of bore before application factors. For a 71.438 mm shaft the usual cone seat is k5 with an H7 housing when the inner ring rotates; arrange two 33281 bearings as a set for two-direction location and set clearance from the load diagram, never from assembly feel. Cross-section geometry: the 23.0 mm half-section ((117.475−71.438)/2) of this 33200-series unit places the roller large-end pitch diameter at roughly 94 mm, and the 30.162 mm axial width is split between cone (17 mm) and cup rib (14 mm) — a geometry that sets the contact angle and, with the 1250 g rotating cone mass, the critical speed at which cage-roller imbalance begins. Why the cup reference matters here: in the 33000-series tables the 33281 cone appears against several cup options. 33281 is the pairing with 33462, and that choice — not the cone — fixes the 117.475 mm OD, the raceway track position and the 30.162 mm assembled width.Ordering number SKF 33281/33462 in SKF catalogue PUB BU/P1 17000 denotes a single-row tapered roller bearing for a 71.438 mm shaft, inch series, with an open pressed-steel-cage execution and one-direction axial capacity.
Typical equipment & failure modes
Common applications
- large process pump and compressor shafts
- rolling-mill auxiliary drives
- crane sheave and hoist gearboxes
- crane sheave and hoist gearboxes
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
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- Mount the 71.438 mm bore 33281 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 332 series at 71.438 mm bore (117.475×30.162 mm) is the wide medium-section choice — more capacity than 302 in the same OD class but a wider footprint; re-check housing width and pair setting before substituting.
- Setting is a design value, not an assembly feel: excessive preload in the 33281 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 33281 mounting error.
- The 33281 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 152/190 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 33281 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 33281/33462 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
How does the 33281 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 33000-series code marks the dimensional series. The metric dimensions 71.438×117.475×30.162 mm are the converted equivalents of the original inch boundary dimensions.
What do the cone and cup numbers in 33281 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 (33000-series) groups sizes that share the same boundary-dimension plan.
Can a single 33281 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 33281 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 33281 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
What shaft and housing fits suit 33281?
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 30.162 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.
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.