8477.20.00.55 - With a screw size less than 6.4 cm

This HTS classification, 8477.20.00.55, specifically covers extruders designed for processing thermoplastics that have a screw size measuring less than 6.4 centimeters in diameter. These machines are integral to the manufacturing of various plastic products through a continuous extrusion process, where heated thermoplastic material is forced through a die. Examples include extruders used for producing films, sheets, profiles, pipes, and filaments where the smaller screw diameter is suitable for specific production scales or material types.

This category is distinguished from its sibling, 8477.20.00.65, solely by the physical dimension of the extruder's screw. While both subcategories fall under "Other, including multiple screw" extruders for processing thermoplastics, the critical differentiator for classification under 8477.20.00.55 is the screw diameter being strictly less than 6.4 cm. This distinction is based on the engineering design and intended application, often relating to the volume of material processed per cycle and the fineness of the output.

As this is a leaf node in the HTS classification structure, there are no further subcategories. Therefore, the classification hinges entirely on the correct identification and measurement of the screw size in relation to the 6.4 cm threshold, along with confirmation that the extruder is indeed intended for processing thermoplastics and falls within the broader scope of extruders as defined in heading 8477.