Abstract: A continuous extrusion machine has a rotatable wheel with a continuous groove in a wall. A fixed shoe structure associated with the wheel provides a passageway and an abutment on the shoe structure closes off one end of the passageway. An extrusion die leads from the passageway at or adjacent the abutment. The entire wheel is located within a hood which is sealed except for apertures for the feedstock, the extruded product and the flash which is removed from the groove. A gaseous, non-oxidizing atmosphere is provided in the hood at a pressure greater than the atmosphere outside the hood. This prevents oxide and other contaminants from entering into the extruded product.