Everyone is familiar with shaping and smoothing metal with a file. Today, however, few know much about files. In the past, they were the workhorses of tool-and-die shops, machine shops and repair garages and often called a German milling machine. While files are intended for working metal, their cousin, the rasp, has long been used for working wood, bone, antler, horses’ hooves, and today, plastics.
Files Versus Rasps
Files have repeating forward-leaning, knife-edge ridges that can cut metal when placed flat on the work and pushed forward. The ridges can be single cut, with a single row of ridges angled at between 5 and 15 degrees to the center line of the file. Double-cut files
