8430.31.00.40 - Rock breaking machines

This HTS category, 8430.31.00.40, specifically classifies self-propelled machinery designed for breaking rock. These machines are typically powered by their own onboard engine and are equipped with mechanisms like hydraulic hammers, rippers, or milling drums that are directly applied to fracture and break solid rock formations. Their primary application is in construction, mining, quarrying, and tunneling operations where the initial breakdown of rock is a crucial step.

This subcategory distinguishes itself from its sibling, 8430.31.00.80 (Other), by focusing exclusively on machines that are self-propelled. While the broader category of coal or rock cutters and tunneling machinery encompasses a wider range of equipment, this specific code narrows the scope to those units that possess independent locomotion capabilities, allowing them to move to and operate at various locations without external towing or propulsion.

As this is a leaf node, there are no further subcategories. Classification within 8430.31.00.40 is therefore determined by the defining characteristics of the machine: its function as a rock breaker and its self-propelled nature. Examples include self-propelled hydraulic breakers used for road construction or demolition, and self-propelled milling machines for rock excavation in tunnel boring projects.