RexnordFX3U216N2-Bolt Alignable Flange Ball Bearing Unit 1″ Bore, Setscrew Locking, Type N Seals, Cast Iron

Product Description

What this part is

A Rexnord Link-Belt FX3-U216N mounted ball bearing unit — a two-bolt alignable flange block in cast iron for a 1 inch shaft, from the 3-200 standard-duty ball bearing series. The insert is a wide inner ring ball bearing with setscrew locking, and it seats spherically in the housing so the unit takes up shaft-to-housing angular error at installation.

Decoding the designation

FX3 = Link-Belt two-bolt alignable flanged unit, 3-200 series. U = wide inner ring ball insert with setscrew locking. 216 = shaft size in sixteenths of an inch, so 16/16 = 1 inch bore. N = type N seal, the standard grease-lubrication seal in this family. Written in the catalogue form it reads FX3-U216N.

Housing style, read this before ordering

Two bolts. Link-Belt’s four-bolt flange in the same series is F3-U200N, and the three-bolt unit is FB3 — different bolt patterns, none of which share a footprint. This is not a pillow block either; those carry P3, PL3, PH3 or PT3 prefixes. Bolt count and pattern are part of the housing style, so count the holes on the housing you are replacing rather than working from the bore.

Published specifications

Housing style: two-bolt alignable flanged unit, cast ironBore / shaft size: 1 in (25.4 mm)Series: Link-Belt 3-200, standard duty ball bearing unitsInsert: U-series wide inner ring ball bearing, spherical outer raceLocking method: set screws in the extended inner ringSeal: type NLubrication: greaseRolling elements: ball · number of rows: 1Design units: inch

What these specs mean in practice

Setscrew locking holds in either direction of rotation, which makes this the safer choice over an eccentric collar unit on a reversing drive. The trade-off is that the screws indent the shaft, so treat the position as fixed once set — moving the unit later means a fresh set of marks.

Alignable refers to installation, not running. The insert swivels in its spherical seat to absorb the angular error of a frame that is not perfectly square, but it will not follow a shaft that keeps moving in service.

A two-bolt flange has a compact face and a diagonal bolt pattern, which suits tight light-duty positions. It also resists moment loads less well than a four-bolt square housing, so keep overhung sprocket and pulley loads modest.

Quantity and configuration

Sold as 1 pc — one complete unit, cast iron housing with the insert and setscrews fitted. Mounting bolts are not included.

Fitting notes

Bolt to a flat, square face and shim rather than pulling the flange onto a high spot; a distorted mounting face consumes the alignment allowance before the shaft turns. Slide onto the shaft, set the position, torque both setscrews evenly, then rotate by hand and confirm the insert still swivels in its seat. Purge the grease path with fresh compatible grease before running.

Interchange guidance

Two-bolt flange units at 1 inch bore also come from Dodge (F2B), SealMaster (SFT, FT), SKF (FYT) and Hub City (FB). Flange face dimensions and bolt centres differ by maker, so measure before treating any as a drop-in. Related, not interchangeable: F3-U216N is the four-bolt version of this unit, FX3-UG216N substitutes an eccentric collar for the setscrews, and the U insert alone is available separately if your housing is sound.