源语言: 英语
in. in diameter and are regarded as a semi-finished product. Before drawing, the scale on the rods is removed by acid pickling or other suitable method and the rods are then dipped into a vat containing hydrated lime in suspension, or other material such as borax in so¬lution, and are then baked to dry the coating. Such lime or borax coatings not only prevent rusting of the cleaned rods, but also act as a carrier for the lubrica
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