... 2) Material: Inconel 718, inconel 625, monel, hastelloy etc Valve stem 1) Process; Hot forging 2) Material: Inconel 718 ... Main material of our forgings include various superalloys and duplex stainless steels. eg. Inconel, Monel, Incoloy, Hastelloy, and Duplex ... and stainless steels. The main materials include Nickel-base alloys, Iron-base alloys, and Cobalt-base alloys ,etc. stainless steel valve stem