UCPX11 bearing: complete specifications & equivalents
The UCPX11 is a JIS B 1559 radial bearing sized 55 x 120 x 65.1 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 55 mm |
| Outer diameter D | 120 mm |
| Width B | 65.1 mm |
| Seal / shield | 2RS |
| Basic dynamic load rating C | 58 kN |
| Basic static load rating C0 | 36 kN |
| Fatigue load limit Pu | 2.83 kN |
| Mass | 5400 g |
| Housing height H | 69.8 mm |
| Housing overall length L | 260 mm |
| Mounting bolt center distance J | 184 mm |
| Mounting hole diameter N | 25 mm |
| Manufacturer designation | UCPX11 |
| Standard | JIS B 1559 |
| Catalog version | CAT. No. 2203-3/E 2024 |
| Last verified | 2026-09-25 |
Source: catalog reference (CAT. No. 2203-3/E 2024) · extracted 2026-09-25
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (CAT. No. 2203-3/E 2024); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & UCP-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 4.724 in |
| Width B | 2.563 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 32.5 mm |
| Smallest bore in UCP-series | 12 mm |
| Largest outer diameter in UCP-series | 300 mm |
| Width range across UCP-series | 31–145 mm |
| Bore position in UCP-series (smallest first) | 11 of 25 |
| Bore above smallest UCP-series size | 43 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| UCPX11 | ISO 15 | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range. Brand-specific OEM equivalents pending multi-source data. |
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 UCPX11 model number is decoded
The NTN UCPX11 unit pairs a UCX11D1 sealed ball bearing insert with a one-piece PX11 cast-iron pillow block housing, delivered aligned, greased and ready to bolt down. On the nameplate, UCPX11 decodes as a UC wide-inner-ring insert in a P plummer block, X-series duty, 55 mm bore; the UCX11D1 designation shows the D1 greasable execution. Boundary data for the 55 mm bore: housing centre height 69.8 mm, base 260 mm, mounting centres 184 mm for M20 fasteners through 25 mm holes; the UCX11D1 insert itself is 120 mm OD. The X section is NTN’s intermediate-duty build: a wider UCX insert with a higher rating sits in a longer, sturdier housing than the 2-series unit at the same bore. The upright base carries the shaft parallel to and above the mounting surface, which is the arrangement fan, conveyor and transmission drives use whenever a plinth or rail is available. At 55–90 mm bore the units carry serious conveyor, fan and crusher-feed drives; housing stiffness, foundation condition and bolt torque matter as much as the insert rating. HVAC air-handling units carry fan shafts on this size, usually in warm roof-space air where the grease must be rated for continuous ambient temperature rather than load. On V-belt drives, align the pulleys before finally tightening the feet; the spherical seat lets you rotate the unit, but sliding the whole base on the foundation is what removes the belt-edge wear. Basic ratings of the UCX11D1 insert are 58 kN dynamic and 36 kN static; the assembled UCPX11 weighs about 5.4 kg.
Typical equipment & failure modes
Common applications
- process fans and induced-draft drives
- quarry feeder and transfer drives
- sawmill arbors and feed rolls
- cold-store and winter-outdoor service needing low-temperature grease
Known failure patterns
- water-emulsified grease after washdown with the fitting facing upward
- setscrew loosening and inner-ring fretting on a shaft that was never re-torqued after run-in
- insert brinelling from hammer mounting or from belt tension applied to a stationary unit
Selection pitfalls — read before you substitute
- Do not confuse UCPX11 with a bare UCX11D1 bearing: replacing only the insert is possible, but the housing PX11 must be unworn and the spherical seat cleaned and coated with anti-seize.
- When ordering covers for UCPX11, note the steel and cast-iron cover executions change the unit mass and envelope but not the 184 mm mounting centres.
- At 55 mm bore the 260 mm base of UCPX11 is a structural member: grout or machine the foundation, because a bedded-on-edges housing concentrates the full belt pull on two cast feet.
- The X insert of UCPX11 is wider and rated above the 2-series part at 55 mm, but it is not interchangeable with a 3-series unit in a damaged application — check the housing length and bolt centres before swapping.
- As a pillow block, UCPX11 needs a prepared horizontal surface at the 69.8 mm centre height: shim both feet with full-width packs so the 260 mm base seats over its full area.
Frequently asked questions
How is UCPX11 locked to the shaft, and how tight should the setscrews be?
The UCX11D1 insert uses two collar setscrews on the 55 mm shaft. Tighten them to NTN's torque table for this bore size in sequence — half torque on the first, full on the second, then back to the first — and re-torque after the first 24–48 running hours once the collar has seated.
When should I choose a pillow block like UCPX11 instead of a flanged unit?
Choose the UCPX11 pillow block when the shaft runs parallel to a horizontal base plate, rail or plinth — the upright housing holds the shaft centre 69.8 mm above the 260 mm bolt-down base. Choose a UCFL flange when the shaft meets a vertical frame face and the housing bolts flat against it.
Can I replace just the insert inside an UCPX11 unit?
Yes — UCPX11 is an assembly of the PX11 housing and UCX11D1 insert, and the insert can be ordered separately if the spherical seat and feet are undamaged. Clean the seat, coat it with anti-seize, and confirm the setscrew indentations on the 55 mm shaft are not the reason the old insert failed.
What are the dimensions of an UCPX11 mounted bearing?
UCPX11 takes a 55 mm shaft (insert UCX11D1, 120 mm OD) and has a unit mass of about 5.4 kg. Housing figures: centre height H 69.8 mm, length L 260 mm, bolt centres J 184 mm, foot holes 25 mm for M20 bolts.
What does the UCPX11 designation mean?
UC identifies the wide-inner-ring, setscrew-locking ball bearing insert; P the upright pillow block housing; X is the duty series; the last digits encode the 55 mm bore. UCPX11 is built from housing PX11 plus insert UCX11D1 (D1 = greasable).
Reviewed & verified by the MPN Base engineering desk against source catalog CAT. No. 2203-3/E 2024 on 2026-09-25. Read our editorial & correction policy.