Weld neck flanges are a flanges with a heavy welding neck which is hot formed from a circular section of steel plate having a small co-axial hole in the center. Weld Neck Flanges are available with following specifications : Stainless Steel : ASTM A 182, A 240 Grade : F 304, 304L, 304H, 316, 316L, 316Ti, 310, 310S, 321, 321H, 317, 347, 347H, 904L, Duplex stainless steel UNS S31803, 2205, Super Duplex stainless steel UNS S32750Carbon Steel : ASTM A 105, ASTM A