This 6 pcs set of hardness testers is made by Tsubosan in Japan.
These files have curved ends which easily reach internal spaces of pipes, grooves and channels. The set is also highly portable so the files can be taken anywhere on site.
These testers are the perfect tools for testing the hardness of your hand tools especially if you are concerned that there may be an issue with edge retention.
Some of their features are:
Non-slip handle, making it easy to use.
the hardness test is applicable for flat surface, curving surface and inner-edge surface.
This new innovative file set provides a quick, inexpensive and simple way to check material hardness. No need to bring the material to be tested over to a hardness testing machine. Just bring this file set 6 files from 40 to 65 HRC to the piece to be tested. Follow these simple steps to test your material:
Start with the BLACK handle file 65 HRC and run the file over the test material. If it marks the material, the material is less than 65 HRC.
Try the BLUE handle file 60 HRC). If it does not mark the material, the file is softer than the material. In this case the material is between 60 and 65 HRC.
If the BLUE handle file 60 HRC does mark the material, simply try the GREEN file 55 HRC), the LIGHT-GREEN handle file 50 HRC) and continue until the material is not marked. The approximate hardness of the material is between the file that marks the material and the file that slips over the material.