Hammering consists of hitting a metal plate on an anvil, also called a horn, with a hammer. Then, the plate is heated in order to soften it again, before repeating the operation until the desired shape or volume is obtained. The part is then polished to reduce any traces of the process. The different elements of the pyxis of Saint-Omer, its circular foot, its flattened node and its cylinder surmounted by a conical roof result from the use of this technique.
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