Flattened jar of forged bronze with silver decoration. “Yū”

Hammer forming

In hammer forming (tankin), a mallet is used to shape a sheet of metal by hammering it into recessions in a wooden stump or block. Next, the metal sheet is worked on the end of specially shaped iron bars known as forming stakes (ategane) to gradually create the final form. It takes tens of thousands of hammer strikes to produce a single finished work.