Skidders are self-propelled wheeled or tracked vehicles that drag logs from the felling site and are classified under heading 8436 (agricultural and forestry machinery) or 8704 (motor vehicles), not under 8428. Log handling equipment at 8428900310 covers stationary or semi-mobile machinery — such as log stackers, debarking infeed systems, or log turners — that handles timber within a processing facility rather than in the field. The distinction turns on whether the machine is primarily a transport vehicle or a materials-handling device.

Multi-function machines are classified by their principal function under GRI 3(c) or by the heading that most specifically describes them. If the machine's primary commercial purpose is lifting or handling (e.g., a robotic palletizer), 842890 or a more specific subheading of 8428 may apply. If processing (cutting, forming, mixing) is the dominant function, a heading in 8479 or another chapter is likely more appropriate. A binding ruling from CBP is advisable for complex multi-function equipment with significant duty implications.