《天工开物·中篇·冶铸》
先锉铜钱的边沿，方法是用竹条或木条穿上几百个铜钱一起锉。然后逐个锉平铜钱表面不规整的地方。
凡钱先错边沿，以竹木条直贯数百文受钅差，后钅差平面则逐一为之。
The first step was to file the edges of the copper coin using bamboo or wood strips with hundreds of copper coins. Then smooth the irregular surfaces of the copper coins one by one.