... .Our flanges are also used in industry where pipe lines require high pressure flanges and we use ... F5, F6, F9, F7, F11, F12, F21, F22 Stainless Steel : 304,304H,304L,310,310 S,321,321H, 316Ti, ... #,400 #,600#,900#, 1500# & 2500 #. Technical Specifications Nominal Pipe Size (NPS)Outside Dia of Flange 'O'Thickness of Flange ... 57636.57688.936.576143.764144.526128.27-- bright 904L stainless steel forge flange