Milking machines (843410) are those that extract milk directly from the animal. Dairy machinery (843420) covers downstream processing equipment — separators, pasteurizers, homogenizers, and similar units — that handles milk after extraction. If a unit performs both functions, classification follows its principal function per the General Rules of Interpretation.

Yes. Parts of milking machines and dairy machinery fall under 843490 rather than with the complete machines. Importers should verify that a part is dedicated to equipment in this heading and not more specifically provided for elsewhere in the tariff schedule.