Rare Tsubotama Smith-made Finishing Files

We have three types of blacksmith-made very fine finishing files appropriate for resharpening teeth on dozuki and other fine saws.

These files are known as "oily files" or "whetstone files" and are very unique. They are triple cut (the teeth run in three directions) at a scale fine enough to be visible under a microscope. They also have a 90 degree rake angle, meaning the teeth are standing perfectly perpindicular to the face, so they will cut on both the push and pull stroke.

These are called "oily files" because they are quenched in oil for maximum hardness, and they are much harder than their machine made counterparts. The "whetstone file" name refers to the fact that they behave like Japanese whetsones: their teeth are so hard they will break off during use, exposing new fresh edges.

These files were only handmade by filesmiths, the last of whom died in the 1970s. Tsubotama files are so valued that some metate (professional saw sharpeners) intend to retire when they are no longer available. 

Compared to Kakumatsu files, the cut on all three is very smooth. The three could be used as a set for roughing out, refining and smoothing the teeth on a dozuki or hozohiki, or as a single file to finish work on a ryoba or larger saw.