Flange Mount Pillow Block Bearing Units UCFC200 Series UCFC300 Series Flange Mount Bearing Units 1). Solid Cast Iron Housing 2). Large Load Capacity and Long Service Life 3). Competitive Price Flange Mount Bearing Units Type: UCFC 200 Series, and UCFC300 Series 1). Structure of Pillow Blocks The outer ring of the self-contained ball bearing in ground to a sphere and the bore of housing in machined to a matching radius. This permits self-aligning between the two members.