Shasan Piping Solution is a well-known stockist and manufacturer of ASTM A860 carbon steel butt weld pipe fittings and has no problem machining and welding to this specification. The material for ASTM A860 carbon steel long radius angle butt weld pipe fittings is described as a super stainless steel with a 50/50 austenite and ferrite microstructure. https://www.shasanpiping.com/carbon-steel-astm-a860-buttweld-fittings-manufacturers-exporters-suppliers-stockists.html