UCFL320 bearing: complete specifications & equivalents
The UCFL320 is a JIS B 1559 radial bearing sized 100 x 215 x 108 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 | 100 mm |
| Outer diameter D | 215 mm |
| Width B | 108 mm |
| Seal / shield | 2RS |
| Basic dynamic load rating C | 192 kN |
| Basic static load rating C0 | 141 kN |
| Fatigue load limit Pu | 8.75 kN |
| Mass | 26000 g |
| Housing height H | 440 mm |
| Housing overall length L | 270 mm |
| Mounting bolt center distance J | 360 mm |
| Mounting hole diameter N | 44 mm |
| Manufacturer designation | UCFL320 |
| 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 | 3.937 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 4.252 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 57.5 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) | 20 of 25 |
| Bore above smallest UCFL-series size | 88 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| UCFL320 | 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 UCFL320 model number is decoded
In NTN's mounted-bearing range, UCFL320 is the two-bolt rhombus flange option for a 100 mm shaft: insert UC320D1, housing FL320, through-bolt mounting. The code breaks down as insert family UC, housing form FL (flange), duty series 3, bore code ending in the 100 mm shaft size; the unit is built from insert UC320D1 and housing FL320. For the frame-face drawing of UCFL320: the two holes are 360 mm apart (J), the rhombus spans 270 mm (L) and 440 mm (H), and M39 (44 mm) bolts clamp it around the 100 mm shaft. 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. 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. Quarry and aggregate conveyors specify this unit because maintenance crews can unbolt the whole assembly and swap it in minutes; interchangeability across brands at the JIS dimensions is part of the selection logic. Cold-climate users should order the low-temperature grease option or repack before commissioning: the factory fill is a general-purpose NLGI 2 that channels poorly below about −20 °C and starves the ball set on start-up. Basic ratings of the UC320D1 insert are 192 kN dynamic and 141 kN static; the assembled UCFL320 weighs about 26.0 kg.
Typical equipment & failure modes
Common applications
- steel-plant roller tables
- large induced-draft fans
- quarry and aggregate screens
- frequent stop-start and reversing duty such as shuttle and tripper conveyors
Known failure patterns
- 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
- over-greasing that churns the charge, overheats the bearing and blows the seal lip
Selection pitfalls — read before you substitute
- The 3-series insert makes UCFL320 the highest-rated unit at 100 mm; its advantage disappears on a soft foundation, so spend the saved margin on base stiffness rather than skipping shims.
- As a rhombus flange, UCFL320 pulls against the frame through only two M39 bolts on 360 mm centres; the mounting plate must be stiff enough not to bend between them under belt load.
- When ordering covers for UCFL320, note the steel and cast-iron cover executions change the unit mass and envelope but not the 360 mm mounting centres.
- Foundation design for UCFL320 must resist the belt-pull reaction at 440 mm centre height — a moment arm this large walks an inadequately anchored base under load.
Frequently asked questions
What are the dimensions of an UCFL320 mounted bearing?
UCFL320 takes a 100 mm shaft (insert UC320D1, 215 mm OD) and has a unit mass of about 26.0 kg. Flange figures: height H 440 mm, length L 270 mm, bolt centres J 360 mm, holes 44 mm for M39 bolts.
What does the UCFL320 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 100 mm bore. UCFL320 is built from housing FL320 plus insert UC320D1 (D1 = greasable).
How is UCFL320 locked to the shaft, and how tight should the setscrews be?
The UC320D1 insert uses two collar setscrews on the 100 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 UCFL320 instead of a pillow block?
Choose the UCFL320 two-bolt flange when the 100 mm shaft meets a vertical frame or side plate: the diamond housing bolts flush with two M39 bolts on 360 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.