ASTM A265, B366, B463 B464, B471, B472, B473 B474, B475UNS N08020High corrosion resistance BLASME B16.54 -300LB BL 6"-300LB BLMaterials can be F20, alloy 20, Hatelloy C, Monel , and Inconel 625Product picture: alloy 20 F20 UNS N08020ASME B 16.5 4- 300LB Blank flange