grinding

Abrasive machining using a rotative disc with abrasive paper.

Grinding (or lapping) is carried on a cast iron disc (lapidary) of different diameters and covered with a more or less coarse abrasive paper. This is one of the first operations of the polisher "prépareur", allowing to roughly eliminate the largest asperities.

 

source : www.cpih.ch/fr/m6/Doc_a_tel/fichiers/BrochurePolisseur08.pdf