API Ring Joint Gaskets are machined from variety types forged solid metal such as Soft Rron,ANSI304,ANSI316,Low carbon and alloy metals(including alloy825,alloy625,Duplex,Monel etc). they are designed for high pressure and temperature applications by selecting the suitable shape and material. Ring joint gaskets assemblies seal by an initial line contact or an edging action as the compressive forces are applied. The hardness of the ring should always be 20-30HB less than the flanges hardness to prevent flange deformation. Dimensions for standard ring joint gaskets and grooves are covered in ASME B16.20 and API 6A, API 17D and ASME B16.5/B16.20.