Let's start by defining the term planishing, which means to smooth by light hammering. Metalworkers have been planishing sheetmetal parts ever since hammers were invented. The basic idea is that ...

Data Source National Museum of American History https://n2t.net/ark:/65665/ng49ca746a1-2c61-704b-e053-15f76fa0b4fa nmah_323167 NMAH HAMMER, PLANISHING National Museum of American History CC0 ...