NTNUCFU-3/4MFG1Four-Bolt Square Flange Mount Bearing Unit, 3/4 in Bore, Setscrew Locking, Sealed for Life

Product Description

What this part is

A complete housed ball bearing unit in the four-bolt square flange style, from NTN’s Ultra-Class line. The one-piece cast iron housing carries a black oxide finish and takes four mounting bolts at the corners of a square pattern. Bore is 3/4 in (19.050 mm). Locking is by two setscrews in the extended inner ring. The unit is sealed for life and non-relubricatable, so there is no grease fitting.

Decoding the designation

UC — wide inner ring insert bearing, setscrew locking, spherical outer surface for self-alignment
FU — four-bolt square flange housing in the Ultra-Class sealed-for-life construction
3/4 — inch bore, 0.750 in
Insert bearing number A-UC204-012D1/LP09M; housing number FU204V65. The 204 size code carries a 3/4 in bore in the inch range, coded 012 as twelve-sixteenths.

Housing style and bolt pattern

Four bolts, centre-to-centre 2.5000 in (63.5 mm) on each side of the square. Bolt hole diameter 0.4219 in (10.7 mm). Flange square across the flats 3.3750 in (85.7 mm).

What these specs mean in practice

A four-bolt square flange spreads the mounting load across four fasteners on a symmetrical pattern, which resists the overhung moment from a belt or chain pull better than a two-bolt flange of the same bore. The Ultra-Class sealed-for-life construction runs on its factory grease charge for the life of the unit; it suits sealed or inaccessible positions and washdown duty, and it raises the speed ceiling to 6660 RPM against a relubricatable equivalent. The spherical outer race takes up initial mounting misalignment at installation.

Published ratings and mounting data

Bore (d): 0.750 in / 19.050 mm
Flange square (L): 3.3750 in / 85.7 mm
Bolt centre-to-centre (J): 2.5000 in / 63.5 mm
Bolt hole diameter (N): 0.4219 in / 10.7 mm
Total housing width (A): 1.1563 in / 29.4 mm
Housing overall depth (A0): 1.4688 in / 37.3 mm
Flange thickness (A2): 0.7500 in / 19.1 mm
Insert bearing width (B): 1.2205 in / 31.0 mm
Inner ring extension (S): 0.5000 in / 12.700 mm
Dynamic load rating: 14.20 kN / 3192 lbf
Static load rating: 6.65 kN / 1495 lbf
Maximum rotational speed: 6660 RPM
Weight: 0.820 kg / 1.799 lb
Operating temperature range: −40 to 120 °C / −40 to 250 °F

Quantity and configuration

1 Pc. Complete housed unit: cast iron four-bolt square flange housing with the insert bearing and setscrews fitted. Contact nitrile seals both faces, open end type, light duty performance class, sealed for life.

Fitting notes

The unit mounts against a flat rigid face, shimmed where uneven. The four flange bolts are drawn down first so the spherical insert settles into its aligned seat, then the setscrews are tightened against the shaft. Shaft seat is a commercial ground 0.750 in diameter.

Interchange guidance

Same-style four-bolt square flange units with setscrew locking in 3/4 in bore share the 204 housing envelope and the 2.5000 in bolt pattern: NTN UCF204-012D1, AMI UCF204-12, Asahi UCF204-012, FYH UCF204-12, Koyo UCF204-12. Those are relubricatable through a grease fitting rather than sealed for life, so the mounting geometry interchanges while the lubrication provision differs. The two-bolt NTN UCFL204-012 and the four-bolt round NTN UCFC204-012 use the same insert but a different housing and bolt pattern, so they are related sizes rather than interchanges.