UCFL305 bearing: complete specifications & equivalents

Specification table

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.

Cross references & equivalents

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 UCFL305 model number is decoded

For a 25 mm shaft ending at or passing through a vertical frame face, NTN UCFL305 is the diamond-flange answer: UC305D1 insert inside the FL305 cast-iron housing. The UCFL305 number follows NTN's mounted-unit convention: housing letter FL, 3-series section, bore code for 25 mm; FL305 and UC305D1 are the separate housing and insert part numbers inside. Shaft size is 25 mm; the 150 mm overall-height flange is 80 mm long across the rhombus (L), with its two mounting holes on 113 mm centres (J) clearing 19 mm M16 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. Most general industrial shafting in the 25–50 mm range ends up on exactly this class of unit: designers trade the 2, X and 3 sections against conveyor centres and belt tension rather than against absolute capacity. Textile and fibre-processing machines use these units on long line-shafting; several bearings share one shaft, and the self-aligning feature prevents one poor bracket from loading its neighbours. A film of anti-seize on the spherical surfaces at assembly prevents fretting corrosion welding insert to housing — the failure mode that turns a five-minute insert swap into a housing replacement. Basic ratings of the UC305D1 insert are 23.5 kN dynamic and 10.9 kN static; the assembled UCFL305 weighs about 0.9 kg.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Never weld a bracket to the FL305 housing of UCFL305: local heat cracks cast iron and distorts the spherical bore that the insert depends on.
• With a 25 mm shaft the M16 foundation bolts of UCFL305 must be re-checked after run-in — paint crush under the feet is enough to loosen both the feet and the setscrews.
• The 3-series insert makes UCFL305 the highest-rated unit at 25 mm; its advantage disappears on a soft foundation, so spend the saved margin on base stiffness rather than skipping shims.
• As a rhombus flange, UCFL305 pulls against the frame through only two M16 bolts on 113 mm centres; the mounting plate must be stiff enough not to bend between them under belt load.
• The lip seals and slingers on UCFL305 suit ordinary industrial dust; submerged or heavy slurry service needs a different sealed arrangement regardless of the load rating.