4010.35 - Endless synchronous belts of an outside circumference exceeding 60 cm but not exceeding 150 cm:

Category 4010.35 specifically classifies endless synchronous belts, also known as timing belts, that are constructed from vulcanized rubber and possess an outside circumference greater than 60 cm but not exceeding 150 cm. These belts are engineered with precisely shaped teeth or profiles on their inner surface, designed to mesh with corresponding grooves on pulleys, ensuring a positive, non-slip drive. Their primary function is the synchronized transmission of rotational motion, crucial in applications requiring precise speed and position control.

This classification distinguishes itself from its siblings primarily based on two factors: the belt's specific type (synchronous) and its defined circumference range. For example, sibling categories 4010.31 through 4010.34 cover endless transmission belts of trapezoidal cross-section (V-belts), which rely on friction for power transmission and have different circumference specifications. Category 4010.36, another synchronous belt, covers those with a larger circumference range, exceeding 150 cm.

Within category 4010.35, further subdivisions are made to account for the belt's construction. The subcategory "Combined with textile materials" accounts for synchronous belts where reinforcement layers of textile fabrics are incorporated into the rubber structure to enhance tensile strength and dimensional stability. The residual category, "Other," captures synchronous belts within the specified circumference that do not incorporate textile materials in their construction.