UCFL208 bearing: complete specifications & equivalents
The UCFL208 is a JIS B 1559 radial bearing sized 40 x 80 x 49.2 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 | 40 mm |
| Outer diameter D | 80 mm |
| Width B | 49.2 mm |
| Seal / shield | 2RS |
| Basic dynamic load rating C | 32.5 kN |
| Basic static load rating C0 | 17.8 kN |
| Fatigue load limit Pu | 1.24 kN |
| Mass | 1500 g |
| Housing height H | 175 mm |
| Housing overall length L | 100 mm |
| Mounting bolt center distance J | 144 mm |
| Mounting hole diameter N | 16 mm |
| Manufacturer designation | UCFL208 |
| 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 | 1.575 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 1.937 in |
| ISO bore code | 08 |
| Radial section height (D−d)/2 | 20 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) | 8 of 25 |
| Bore above smallest UCFL-series size | 28 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| UCFL208 | 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 UCFL208 model number is decoded
The NTN UCFL208 flanged unit combines a sealed UC208D1 insert with a diamond-shaped FL208 cast-iron housing that bolts flat against a machine frame. The code breaks down as insert family UC, housing form FL (flange), duty series 2, bore code ending in the 40 mm shaft size; the unit is built from insert UC208D1 and housing FL208. For the frame-face drawing of UCFL208: the two holes are 144 mm apart (J), the rhombus spans 100 mm (L) and 175 mm (H), and M14 (16 mm) bolts clamp it around the 40 mm shaft. The 2-series section is the standard-duty choice — the slimmest, lightest housing at this bore, selected when shaft speed and load are moderate and space is normal. 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. The 25–50 mm bore band is the workhorse of industry — belt conveyors, fans, agricultural drives and small process machines — which is why this range has the fullest choice of series and cover options. Renewable-energy biomass handling — chipper infeed, ash drag-out conveyors — uses this unit in pairs, with the locating bearing fixed and the opposite float unit free to slide on its base slots. Relubricate through the fitting while the shaft is turning if at all possible: fresh grease pushes the old charge around the ball set and out past the seals, whereas purging a stationary bearing can rupture the seal lip. Basic ratings of the UC208D1 insert are 32.5 kN dynamic and 17.8 kN static; the assembled UCFL208 weighs about 1.5 kg.
Typical equipment & failure modes
Common applications
- industrial fans and blowers
- agricultural augers and bucket elevators
- small crushers and screening feeds
- cold-store and winter-outdoor service needing low-temperature grease
Known failure patterns
- grease starvation on long intervals in hot positions, with the ball set running on dried thickener
- 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
Selection pitfalls — read before you substitute
- The standard 2-series insert in UCFL208 is the lightest section at 40 mm — do not substitute it into a position that previously ran an X or 3 unit: the 144 mm mounting may match while the load rating does not.
- As a rhombus flange, UCFL208 pulls against the frame through only two M14 bolts on 144 mm centres; the mounting plate must be stiff enough not to bend between them under belt load.
- The D1 suffix on UC208D1 means the greasable execution; a unit without it has no fitting path, so do not assume every UCFL208 on site accepts relubrication.
- Self-aligning is not the same as free to move: the UC208D1 insert of UCFL208 pivots to correct static misalignment, but a continuously bending shaft still frets the spherical seat.
- In this bore band the temptation is to choose UCFL208 on shaft size alone; belt pull often dominates the radial load, so rate the unit against the overhung pulley force, not just transmitted power.
Frequently asked questions
What are the dimensions of an UCFL208 mounted bearing?
UCFL208 takes a 40 mm shaft (insert UC208D1, 80 mm OD) and has a unit mass of about 1.5 kg. Flange figures: height H 175 mm, length L 100 mm, bolt centres J 144 mm, holes 16 mm for M14 bolts.
What does the UCFL208 designation mean?
UC identifies the wide-inner-ring, setscrew-locking ball bearing insert; FL the two-bolt rhombus flange housing; 2 is the duty series; the last digits encode the 40 mm bore. UCFL208 is built from housing FL208 plus insert UC208D1 (D1 = greasable).
How is UCFL208 locked to the shaft, and how tight should the setscrews be?
The UC208D1 insert uses two collar setscrews on the 40 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 UCFL208 instead of a pillow block?
Choose the UCFL208 two-bolt flange when the 40 mm shaft meets a vertical frame or side plate: the diamond housing bolts flush with two M14 bolts on 144 mm centres. A UCP pillow block is used when the shaft runs above a horizontal mounting surface.
How often should I relubricate an UCFL208 unit?
There is no single interval for UCFL208: the UC208D1 insert is regreased through the D1 fitting while the shaft turns, using an NLGI 2 lithium or lithium-complex grease. Quarterly is typical for normal ambient conveyor duty; shorten to weekly or monthly where temperatures exceed about 70 °C, water is present, or dust is heavy.
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.