Cast-in ring heaters are used in various punching, forming, sealing, and warming applications. They are also a direct replacement for mica style ring heaters. The cast-in heating element delivers a robust construction in a low profile design that is well suited for continuous production applications. The ring design can include mounting features such as cast mounting tabs, threaded inserts, and drilled holes. Ring heaters can also be designed as die sets for heated stamping applications.