Source: Nicholson File Co, File Filosophy booklet, 1956, in opd.

Files and rasps are valuable in furniture making. The file -- much more than a smoothing tool — is a cutting and shaping tool, with rows of geometrically arranged burrs, or cutting edges, cut into the flat paddle of steel, as the illustration above illustrates.

Files are made of tool steel

Files were ideal for finishing the surface of end-grain wood such as the narrow edges of a dovetailed drawer front. The joiner found files just the thing for smoothing molding rounds, cleaning out inside curves, rounding corners, and often as a substitute for glasspaper (a forerunner of sandpaper).

For smoothing fine bead moldings, the tang of an old file could be sharpened (with another file) and then bent in a matching hook. This improvised tool did as nice a job as a piece of freshly broken glass, which by the way should be deemed a "tool" in its own right. And files were useful, too, in making patterns or wooden templates. These were generally sawn from quarter-inch pine or basswood, and carefully shaped and faired up to exact contours, a job that a file did better than anything else. On large patterns such as those for chair seats, thin battens were nailed across the grain to prevent their splitting and warping. A hole bored in one corner provided a simple means of storing the pattern, hung on a peg in the wall. From these templates which were more accurately carved than cut, parts of furniture could be easily duplicated, though not in the sense of interchangeability that we are familiar with today.

For smoothing fine bead moldings, the tang of an old file could be sharpened (with another file) and then bent in a matching hook. This improvised tool did as nice a job as a piece of freshly broken glass, which by the way should be deemed a "tool" in its own right. And files were useful, too, in making patterns or wooden templates. These were generally sawn from quarter-inch pine or basswood, and carefully shaped and faired up to exact contours, a job that a file did better than anything else. On large patterns such as those for chair seats, thin battens were nailed across the grain to prevent their splitting and warping. A hole bored in one corner provided a simple means of storing the pattern, hung on a peg in the wall. From these templates which were more accurately carved than cut, parts of furniture could be easily duplicated, though not in the sense of interchangeability that we are familiar with today.

Files were of course used for sharpening axes, cold chisels, screw bits, gimlets, and many other small tools.