Copper Round Bar: Ingot Hammered Round with Annealing

Copper is soft and ductile but stiffens as it is hammered; heating it (annealing) and cooling it in air or water softens it again, the way copper has been worked for a thousand years. Draw a copper ingot out on the anvil to a square, take the corners down to an octagon, then round, annealing whenever it stiffens. The picture: our diagram of the cross-sections.