In scrap metal terminology, “clean” doesn’t mean polished — it means free of contaminants. Clean metal contains only the target material with no attachments, coatings, insulation, paint, plastic, solder, or mixed metals. “Dirty” metal contains impurities that reduce its value because the buyer must spend time and energy removing those contaminants before the metal can be remelted. A two-minute sort before you visit the yard — pulling plastic off copper fittings, removing screws from aluminium frames, separating brass from steel — can increase your payout by $40 to $200 on an average load. At endless metals, cleaner material always earns a higher grade and a better price.