... Seamless rolled ring, fine machining. Forging features:1) Drop forgings, Seamless rolled ring, rough machining and fine machining. The diameter of ... the rings can be 6,300mm max.2) Standards: ASTM, ASME, AISI, API, UNI, DIN, SIS and ... , etc.5) Provide heat treatment , rough machining , finish machining .6) Customers' designs welcomed large flange