87750-87111 bearing: complete specifications & equivalents
The 87750-87111 is a ISO 355 radial bearing sized 190.5 x 282.575 x 50.8 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 190.5 mm |
| Outer diameter D | 282.575 mm |
| Width B | 50.8 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 427 kN |
| Basic static load rating C0 | 695 kN |
| Fatigue load limit Pu | 67 kN |
| Reference speed (thermal) | 1700 rpm |
| Limiting speed (mechanical) | 2000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 9550 g |
| Manufacturer designation | SKF 87750/87111 |
| 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 & 87000-series range
| Bore d | 7.5 in |
|---|---|
| Outer diameter D | 11.125 in |
| Width B | 2 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 46 mm |
| Smallest bore in 87000-series | 187.325 mm |
| Largest outer diameter in 87000-series | 282.575 mm |
| Width range across 87000-series | 50.8–50.8 mm |
| Bore position in 87000-series (smallest first) | 2 of 2 |
| Bore above smallest 87000-series size | 3.1750000000000114 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 87750-87111 | 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 87750-87111 model number is decoded
Housing and abutment design flows from the cup: in 87750 the 87111 cup fixes the 282.575 mm OD, the outer-ring face position and the rib shoulder that the rollers contact under thrust, while the 87750 cone determines the 190.5 mm shaft interface; the 50.8 mm width is the assembled pair value.For a 190.5 mm shaft carrying combined load, SKF lists 87750 under catalogue execution SKF 87750/87111: one open single-row tapered roller bearing in the inch 87000-series.The 87000-series series assigns 190.5 mm bore, 282.575 mm OD and 50.8 mm width to 87750; 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. In SKF suffix language a bare 87750 is the standard execution; B marks a larger contact angle and Q or J2 mark clearance/cage variants, all quoted separately. At 1,700 r/min reference speed the 46.0 mm-section 87750 is governed thermally by preload and lubricant flow; grease or oil selection should be made against that value, with 2,000 r/min as the mechanical ceiling. Mounting practice for 87750: the rotating cone takes the interference fit (m6 on a 190.5 mm shaft), the cup slides for axial location, and reversing-thrust duty demands a paired O/X set rather than one bearing. Cross-section geometry: the 46.0 mm half-section ((282.575−190.5)/2) of this 87700-series unit places the roller large-end pitch diameter at roughly 236 mm, and the 50.8 mm axial width is split between cone (28 mm) and cup rib (23 mm) — a geometry that sets the contact angle and, with the 9550 g rotating cone mass, the critical speed at which cage-roller imbalance begins.
Typical equipment & failure modes
Common applications
- heavy-duty rolling-mill gearboxes
- large crusher and mineral-processing drives
- wind-turbine main shafts
- offshore winch and drawworks drums
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
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- At 190.5 mm bore the cone mass is high enough that cocking during mounting damages the cage and rib; guide the ring square, confirm seat contact around the full circumference, and re-check setting after the first thermal cycle of the paired set.
- The 87000-series inch series at 190.5 mm bore (282.575×50.8 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 87750 mounting error.
- A single 87750 cannot locate the shaft axially in both directions; mounting it singly on a reversing-thrust shaft leaves one direction uncontrolled — always use an O or X matched pair for bidirectional location.
- The 9550 g mass and 50.8 mm width mean spacer and abutment faces must be square to the axis within the bearing's own P0 tolerance; a tilted spacer tilts the contact angle and concentrates load on one rib of 87750.
- The 427/695 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 87750 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 87750/87111 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
Is 87750 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 87750?
The SKF 87750/87111 is a single-row tapered roller bearing with 190.5 mm bore, 282.575 mm outer diameter and 50.8 mm width (7.5 × 11.125 × 2 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 427 kN, C0 695 kN, fatigue load limit Pu 67 kN, reference speed 1,700 r/min, limiting speed 2,000 r/min, mass about 9550 g. It is an open, separable bearing with a pressed-steel cage.
How does the 87750 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 87000-series code marks the dimensional series. The metric dimensions 190.5×282.575×50.8 mm are the converted equivalents of the original inch boundary dimensions.
What do the cone and cup numbers in 87750 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 (87000-series) groups sizes that share the same boundary-dimension plan.
Can a single 87750 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.
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.