UCP328 bearing: complete specifications & equivalents
The UCP328 is a JIS B 1559 radial bearing sized 140 x 300 x 145 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 | 140 mm |
| Outer diameter D | 300 mm |
| Width B | 145 mm |
| Seal / shield | 2RS |
| Basic dynamic load rating C | 280 kN |
| Basic static load rating C0 | 246 kN |
| Fatigue load limit Pu | 13 kN |
| Mass | 84000 g |
| Housing height H | 200 mm |
| Housing overall length L | 620 mm |
| Mounting bolt center distance J | 500 mm |
| Mounting hole diameter N | 40 mm |
| Manufacturer designation | UCP328 |
| 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 | 5.512 in |
|---|---|
| Outer diameter D | 11.811 in |
| Width B | 5.709 in |
| ISO bore code | 28 |
| Radial section height (D−d)/2 | 80 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) | 25 of 25 |
| Bore above smallest UCP-series size | 128 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| UCP328 | 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 UCP328 model number is decoded
A 140 mm bore upright mounted bearing, NTN UCP328 combines the UC328D1 self-aligning insert with the grey-iron P328 pillow block base. On the nameplate, UCP328 decodes as a UC wide-inner-ring insert in a P plummer block, 3-series duty, 140 mm bore; the UC328D1 designation shows the D1 greasable execution. Boundary data for the 140 mm bore: housing centre height 200 mm, base 620 mm, mounting centres 500 mm for M33 fasteners through 40 mm holes; the UC328D1 insert itself is 300 mm OD. The 3-series section is the heavy-duty end of the range: a UC3 high-capacity insert in the longest, strongest housing, specified for shock loads and long conveyor centres. 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 the top of the range the units weigh tens of kilograms and use foundation bolts of M30 and larger; installation is a lifting, alignment and grouting exercise, not hand fitting. Belt-conveyor builders fit this unit at the drive and tail pulleys: the spherical seat absorbs the small angular errors of a welded truss, and the setscrew lock keeps the inner ring stationary on a shaft that reverses every time the belt is run back. Torque the two setscrews in sequence: run the first to half value, the second to full value, then come back to the first; NTN’s recommended setscrew torque rises sharply with shaft size, so use the table for this bore rather than a wrench feel inherited from smaller units. Basic ratings of the UC328D1 insert are 280 kN dynamic and 246 kN static; the assembled UCP328 weighs about 84.0 kg.
Typical equipment & failure modes
Common applications
- ship-loader and stacker drives
- mining and port conveyor pulleys
- primary crusher feeders
- continuous one-direction running where creep risk concentrates on the setscrew points
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 UCP328 with a bare UC328D1 bearing: replacing only the insert is possible, but the housing P328 must be unworn and the spherical seat cleaned and coated with anti-seize.
- When ordering covers for UCP328, note the steel and cast-iron cover executions change the unit mass and envelope but not the 500 mm mounting centres.
- Foundation design for UCP328 must resist the belt-pull reaction at 200 mm centre height — a moment arm this large walks an inadequately anchored base under load.
- The 3-series insert makes UCP328 the highest-rated unit at 140 mm; its advantage disappears on a soft foundation, so spend the saved margin on base stiffness rather than skipping shims.
- As a pillow block, UCP328 needs a prepared horizontal surface at the 200 mm centre height: shim both feet with full-width packs so the 620 mm base seats over its full area.
Frequently asked questions
How is UCP328 locked to the shaft, and how tight should the setscrews be?
The UC328D1 insert uses two collar setscrews on the 140 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 UCP328 instead of a flanged unit?
Choose the UCP328 pillow block when the shaft runs parallel to a horizontal base plate, rail or plinth — the upright housing holds the shaft centre 200 mm above the 620 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 UCP328 unit?
Yes — UCP328 is an assembly of the P328 housing and UC328D1 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 140 mm shaft are not the reason the old insert failed.
What are the dimensions of an UCP328 mounted bearing?
UCP328 takes a 140 mm shaft (insert UC328D1, 300 mm OD) and has a unit mass of about 84.0 kg. Housing figures: centre height H 200 mm, length L 620 mm, bolt centres J 500 mm, foot holes 40 mm for M33 bolts.
What does the UCP328 designation mean?
UC identifies the wide-inner-ring, setscrew-locking ball bearing insert; P the upright pillow block housing; 3 is the duty series; the last digits encode the 140 mm bore. UCP328 is built from housing P328 plus insert UC328D1 (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.