Conversion. Copper and brass processing. Pickling lengths of copper water tube in a brass and copper mill. After annealing, or softening by heat to reduce brittleness and allow further drawing, tubes are "pickled" in a sulphuric acid solution to remove oxide and scale that result from the anneal. Bundles of the tubes are picked up by electric cranes and transported from the pickle to a rinse bath of water. The tubes are then returned to the drawbench for re-drawing down to smaller diameters. Chase Copper and Brass Company, Euclid, Ohio. Sourced from the Library of Congress.