Abstract: A tool assembly for friction extrusion can comprise a friction extrusion die. The friction extrusion die can include a distal face and a proximal end. The distal face can define at least one topographical ridge or groove feature to induce plasticization of a material in response to an axial force and a rotational force applied by the distal face to the material. The friction extrusion die can define a central passage to carry an extrudate of the material in a proximal direction in response to the applied axial and rotational forces. The proximal end can define a faceted cross-sectional profile to mate a with a corresponding receiving end of a tool holder. The faceted cross-sectional profile can be sized and shaped to receive the rotational force through engagement by the tool holder of respective faces defined by the faceted cross-sectional profile.