UCFL328 bearing: complete specifications & equivalents
The UCFL328 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 | 81000 g |
| Housing height H | 600 mm |
| Housing overall length L | 400 mm |
| Mounting bolt center distance J | 500 mm |
| Mounting hole diameter N | 51 mm |
| Manufacturer designation | UCFL328 |
| 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 & UCFL-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 UCFL-series | 12 mm |
| Largest outer diameter in UCFL-series | 300 mm |
| Width range across UCFL-series | 31–145 mm |
| Bore position in UCFL-series (smallest first) | 25 of 25 |
| Bore above smallest UCFL-series size | 128 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| UCFL328 | 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 UCFL328 model number is decoded
UCFL328 belongs to NTN's UCFL line of two-bolt rhombus flanged units, built on a JIS B 1558 UC328D1 insert in a JIS B 1559 FL328 housing. The UCFL328 number follows NTN's mounted-unit convention: housing letter FL, 3-series section, bore code for 140 mm; FL328 and UC328D1 are the separate housing and insert part numbers inside. Shaft size is 140 mm; the 600 mm overall-height flange is 400 mm long across the rhombus (L), with its two mounting holes on 500 mm centres (J) clearing 51 mm M45 bolts. 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 diamond flange carries the shaft square to a vertical face — a welded frame, side plate or gearbox wall — so no base plinth and no shim pack under the bearing are required. Units in this bore class live in quarries, steel plants and port equipment: the ratings are high, but dust, water and foundation movement — not fatigue — usually decide the service life. Cement plant clinker conveyors fit this size under insulation and heat shields; radiant heat dictates both the grease grade and a relubrication interval far shorter than the load alone would suggest. If the unit is the locating bearing, clamp the inner ring with both setscrews and keep the housing feet tight; the opposite unit on the shaft must be the float design with slots, or thermal growth preloads both bearings. Basic ratings of the UC328D1 insert are 280 kN dynamic and 246 kN static; the assembled UCFL328 weighs about 81.0 kg.
Typical equipment & failure modes
Common applications
- quarry and aggregate screens
- ship-loader and stacker drives
- mining and port conveyor pulleys
- long line-shafting where several units must share a straight reference
Known failure patterns
- fretting corrosion of the shaft journal under the wide inner ring after years of micro-creep
- lip-seal failure from grit past the slinger, followed by grease loss and abrasive wear
- spherical-seat fretting that welds insert to housing and destroys the self-aligning action
Selection pitfalls — read before you substitute
- The 3-series insert makes UCFL328 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 rhombus flange, UCFL328 pulls against the frame through only two M45 bolts on 500 mm centres; the mounting plate must be stiff enough not to bend between them under belt load.
- When ordering covers for UCFL328, note the steel and cast-iron cover executions change the unit mass and envelope but not the 500 mm mounting centres.
- XL units like UCFL328 (140 mm bore, M45 bolts) are grouted, shimmed and aligned as civil works; bolting them straight to bare plate guarantees movement and foot cracking.
Frequently asked questions
What are the dimensions of an UCFL328 mounted bearing?
UCFL328 takes a 140 mm shaft (insert UC328D1, 300 mm OD) and has a unit mass of about 81.0 kg. Flange figures: height H 600 mm, length L 400 mm, bolt centres J 500 mm, holes 51 mm for M45 bolts.
What does the UCFL328 designation mean?
UC identifies the wide-inner-ring, setscrew-locking ball bearing insert; FL the two-bolt rhombus flange housing; 3 is the duty series; the last digits encode the 140 mm bore. UCFL328 is built from housing FL328 plus insert UC328D1 (D1 = greasable).
How is UCFL328 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 rhombus flange unit like UCFL328 instead of a pillow block?
Choose the UCFL328 two-bolt flange when the 140 mm shaft meets a vertical frame or side plate: the diamond housing bolts flush with two M45 bolts on 500 mm centres. A UCP pillow block is used when the shaft runs above a horizontal mounting surface.
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.