UCFL313 bearing: complete specifications & equivalents
The UCFL313 is a JIS B 1559 radial bearing sized 65 x 140 x 75 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 | 65 mm |
| Outer diameter D | 140 mm |
| Width B | 75 mm |
| Seal / shield | 2RS |
| Basic dynamic load rating C | 103 kN |
| Basic static load rating C0 | 60 kN |
| Fatigue load limit Pu | 4.6 kN |
| Mass | 7500 g |
| Housing height H | 295 mm |
| Housing overall length L | 175 mm |
| Mounting bolt center distance J | 240 mm |
| Mounting hole diameter N | 31 mm |
| Manufacturer designation | UCFL313 |
| 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 | 2.559 in |
|---|---|
| Outer diameter D | 5.512 in |
| Width B | 2.953 in |
| ISO bore code | 13 |
| Radial section height (D−d)/2 | 37.5 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) | 13 of 25 |
| Bore above smallest UCFL-series size | 53 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| UCFL313 | 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 UCFL313 model number is decoded
UCFL313 belongs to NTN's UCFL line of two-bolt rhombus flanged units, built on a JIS B 1558 UC313D1 insert in a JIS B 1559 FL313 housing. On the nameplate, UCFL313 decodes as a UC wide-inner-ring insert in a FL diamond flange, 3-series duty, 65 mm bore; the UC313D1 designation shows the D1 greasable execution. Boundary data for the 65 mm bore: 295 mm high flange, 175 mm long over the rhombus, 240 mm hole centres for M27 fasteners through 31 mm holes; insert OD is 140 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. Large-bore mounted units like this are selected on calculated bearing life plus foundation quality — the cast base is now a structural part of the drive, not just a convenient clamp. On machine-tool ancillary drives — chip conveyors, coolant pumps, rotary feeders — this unit is chosen because the spherical fit tolerates a frame welded without precision fixtures. The spherical outer diameter of the insert must be free to pivot in the housing bore during alignment; never pin the insert or weld the housing before the shaft has been turned through several revolutions and the alignment set. Basic ratings of the UC313D1 insert are 103 kN dynamic and 60 kN static; the assembled UCFL313 weighs about 7.5 kg.
Typical equipment & failure modes
Common applications
- cement and clinker handling
- sugar-mill and fertiliser plant drives
- heavy bulk-handling conveyors
- vibrating feeder and screen-adjacent positions where setscrew retorque is routine
Known failure patterns
- housing-foot cracking beside an over-torqued or under-supported foundation bolt
- 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
Selection pitfalls — read before you substitute
- The 3-series insert makes UCFL313 the highest-rated unit at 65 mm; its advantage disappears on a soft foundation, so spend the saved margin on base stiffness rather than skipping shims.
- As a rhombus flange, UCFL313 pulls against the frame through only two M27 bolts on 240 mm centres; the mounting plate must be stiff enough not to bend between them under belt load.
- Self-aligning is not the same as free to move: the UC313D1 insert of UCFL313 pivots to correct static misalignment, but a continuously bending shaft still frets the spherical seat.
- UCFL313 at 65 mm uses M27 bolts that need a torque wrench and a cross pattern; pulling one bolt first tips the 295 mm centre height and binds the insert.
Frequently asked questions
What are the dimensions of an UCFL313 mounted bearing?
UCFL313 takes a 65 mm shaft (insert UC313D1, 140 mm OD) and has a unit mass of about 7.5 kg. Flange figures: height H 295 mm, length L 175 mm, bolt centres J 240 mm, holes 31 mm for M27 bolts.
What does the UCFL313 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 65 mm bore. UCFL313 is built from housing FL313 plus insert UC313D1 (D1 = greasable).
How is UCFL313 locked to the shaft, and how tight should the setscrews be?
The UC313D1 insert uses two collar setscrews on the 65 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 UCFL313 instead of a pillow block?
Choose the UCFL313 two-bolt flange when the 65 mm shaft meets a vertical frame or side plate: the diamond housing bolts flush with two M27 bolts on 240 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.