pipe-die

from The Century Dictionary.

• noun In a press for molding earthenware pipes, the ring-shaped die which shapes the exterior surface of the pipe.
• noun A female screw or nut of hardened and tempered steel used for cutting male threads on the ends of metal pipes.
• noun Any one of the radially arranged and simultaneously adjustable screw cutting-tools which in some kinds of pipe die-stocks have their inner ends formed like chasers for cutting male screws. (See chaser.)