NOVELTY – The assembly has a screw matched with a variable screw (8), where the screw is provided with external diameter. Root diameters of other two screws are remained constant. External diameter of a thread is greater than diameter of an entrance region of a material and lower than diameter of region of material output. Internal diameter of a shirt (2) is larger than that of region of a material inlet and lower than that of the region of the material output, where space is formed between a top thread and a jacket. A constant internal diameter (6), a shaft (1), a screw body (3) and a material inlet (7) are provided. USE – Shirt thread assembly for use in a press machine, an injection machine and an extruder machine (all claimed). ADVANTAGE – The assembly adjusts distance between the thread and the shirt so as to set a parameter of a press machine, thus increasing service life of the thread and the shirt, and increasing versatility of the screw and the shirt. DESCRIPTION OF DRAWING(S) – The drawing shows a schematic view of a shirt thread assembly. Shaft (1) Shirt (2) Screw body (3) Constant internal diameter (6) Material inlet (7) Variable screw (8)