Simpson HUC66TF HUCTF Top Flange Concealed Flange Joist Hanger for 6x6 12 Ga G90 Galvanized OCB Ornamental Column Bases Less surface disruption on most Less surface disruption on most jobs because no drilling is required for most applications when ports are pasted directly to the concrete Face down and face vertical milling technique the bit's profile allows the drawer front to be milled with the inside face down on the table simplifying installation on the job site Purpose built for concealed flange applications the two concealed flanges are specifically engineered for end of wall and corner framing scenarios where a conventional hanger with visible flanges would be structurally or aesthetically problematic