Our other sites:

What is a diamond file?

What is a diamond file?

Shop for Files

Image of coarse diamond files showing their grit Diamond files are used for filing extremely hard materials such as hardened steel.

What are the characteristics of diamond files?

Image showing a selection of needle files with different cross sections

Cross section and taper

Diamond files can be found in many of the same shapes as the other files listed in this guide.

A diamond chainsaw file which is not cut with teeth but embedded instead with tiny diamonds


Diamond files are not cut with teeth in the same way as rasps or files.

Image of a pile of tungsten carbide grit, which is used for the manufacture of more affordable diamond files Instead, they have pieces of diamond or tungsten carbide grit embedded in the cutting faces of the tools.
A diamond which has a hardness of 10 on the Moh's scale Diamond is much harder than tool steel and therefore makes for a much more effective abrasive tool.
A DIYer using a diamond file to shape a piece of glass This is the reason why diamond files are effective on tool steel. They can also be used to file brittle materials that would crack or break if a conventional file was used. These materials include ceramic, glass, and some plastics.

For more information on why diamond can abrade steel, see: What is hardness?

Image to illustrate that neither the American nor the Swiss pattern grading systems apply to this file

Swiss or American?

Diamond files use a completely different system for measuring coarseness than American and Swiss pattern files.

Image showing a tools website that will list diamond files according to their grit You will find them listed as having a certain ‘grit’ number, for example ‘325 grit’. The lower the grit number, the coarser the file.
Image to show a diamond file's surface measured in particles per square inch

What is grit?

The term ‘grit’ refers to the number of sharp particles per square inch, so an 800 grit tool would have 800 grains of diamond concentrated into quite a small area.

A diamond file will often have even more diamonds than the crown jewels If you had an 800 grit diamond file with a cutting area of just 4 square inches, that would be more diamonds than there are in the crown jewels!

Wonkee Donkee Tools