1 6AN Male Flare To -6AN Male 90 Degree. 2 The thread size of 6AN is 9/16-18 UNF. -6AN Male Flare 90 Degree -6AN Fitting Male Union BLACK reusable fitting.other sizes available. One-piece, CNC-machined T6061 billet aluminum design ensures the most direct path for unrestricted and redirected flow.