Hardware machinery: a general term for metal parts and mechanical equipment. In industrial production, it refers to components and devices made of metals such as steel, copper, aluminum and iron, which are processed into fasteners, transmission parts, tools, molds and complete machines. "Wu Yue spring and Autumn" IV "Helu internal biography": "I heard that the king of Yue Yuan often sent Ou Yezi to make five swords,... One Zhanlu, the king of hardware and the essence of the sun." According to the note of "gold, knife, turtle and shell" in the annals of food and goods in the Han Dynasty: "gold is the gold of five colors. The yellow one is gold, the white one is silver, the red one is copper, the green one is lead, and the black one is iron.