Abstract: An insulating cap and connector for attaching an electric utility cross arm assembly to a supporting metal utility pole having an open top. A cylindrical tube of insulated composition has an end cap closed at the top and has a reduced diameter nipple extending downwardly. The reduced diameter nipple is insertable within the open top end of the supporting utility pole when the tube is slid over the top of the utility pole. Fasteners attach the cross arm to the tube and the supporting utility pole. There is no conductive contact between the metal support pole and the cross arm when insulated fasteners are used.