UCFL318 bearing: complete specifications & equivalents
The UCFL318 is a JIS B 1559 radial bearing sized 90 x 190 x 96 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 | 90 mm |
| Outer diameter D | 190 mm |
| Width B | 96 mm |
| Seal / shield | 2RS |
| Basic dynamic load rating C | 158 kN |
| Basic static load rating C0 | 107 kN |
| Fatigue load limit Pu | 7.1 kN |
| Mass | 17000 g |
| Housing height H | 385 mm |
| Housing overall length L | 235 mm |
| Mounting bolt center distance J | 315 mm |
| Mounting hole diameter N | 38 mm |
| Manufacturer designation | UCFL318 |
| 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 | 3.543 in |
|---|---|
| Outer diameter D | 7.48 in |
| Width B | 3.78 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 50 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) | 18 of 25 |
| Bore above smallest UCFL-series size | 78 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| UCFL318 | 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 UCFL318 model number is decoded
NTN delivers UCFL318 as a matched unit — the UC318D1 insert is locked into the FL318 rhombus cast-iron flange at the factory and arrives greased and sealed. On the nameplate, UCFL318 decodes as a UC wide-inner-ring insert in a FL diamond flange, 3-series duty, 90 mm bore; the UC318D1 designation shows the D1 greasable execution. Boundary data for the 90 mm bore: 385 mm high flange, 235 mm long over the rhombus, 315 mm hole centres for M33 fasteners through 38 mm holes; insert OD is 190 mm. 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 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. Sawmill and woodworking machinery mounts this unit on saw arbors and feed rolls, where vibration is continuous and the setscrews must be re-checked after the first hours of running. After the first 24–48 running hours, re-torque both setscrews and the foundation bolts — seating of the inner ring on the shaft and crush of any paint under the feet otherwise leaves the bearing loose at the worst possible time. Basic ratings of the UC318D1 insert are 158 kN dynamic and 107 kN static; the assembled UCFL318 weighs about 17.0 kg.
Typical equipment & failure modes
Common applications
- sawmill arbors and feed rolls
- cement and clinker handling
- sugar-mill and fertiliser plant drives
- low-speed heavily loaded pulleys where the static rating governs the selection
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
- The D1 suffix on UC318D1 means the greasable execution; a unit without it has no fitting path, so do not assume every UCFL318 on site accepts relubrication.
- Self-aligning is not the same as free to move: the UC318D1 insert of UCFL318 pivots to correct static misalignment, but a continuously bending shaft still frets the spherical seat.
- At 90 mm bore the 235 mm base of UCFL318 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 3-series insert makes UCFL318 the highest-rated unit at 90 mm; its advantage disappears on a soft foundation, so spend the saved margin on base stiffness rather than skipping shims.
- As a rhombus flange, UCFL318 pulls against the frame through only two M33 bolts on 315 mm centres; the mounting plate must be stiff enough not to bend between them under belt load.
Frequently asked questions
How is UCFL318 locked to the shaft, and how tight should the setscrews be?
The UC318D1 insert uses two collar setscrews on the 90 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 UCFL318 instead of a pillow block?
Choose the UCFL318 two-bolt flange when the 90 mm shaft meets a vertical frame or side plate: the diamond housing bolts flush with two M33 bolts on 315 mm centres. A UCP pillow block is used when the shaft runs above a horizontal mounting surface.
Can I replace just the insert inside an UCFL318 unit?
Yes — UCFL318 is an assembly of the FL318 housing and UC318D1 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 90 mm shaft are not the reason the old insert failed.
What are the dimensions of an UCFL318 mounted bearing?
UCFL318 takes a 90 mm shaft (insert UC318D1, 190 mm OD) and has a unit mass of about 17.0 kg. Flange figures: height H 385 mm, length L 235 mm, bolt centres J 315 mm, holes 38 mm for M33 bolts.
What does the UCFL318 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 90 mm bore. UCFL318 is built from housing FL318 plus insert UC318D1 (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.