If you examine any knapped stone tool, you’ll find that it is shaped like a lens in cross section. Here I’m using an angle grinder to grind that rough shape into the blade blank. I’ve clamped the blade into a vise:

NOTE: THIS IS A HAZARDOUS OPERATION WITH THE BLADE STICKING OUT LIKE THIS. PLEASE USE CAUTION WHILE WORKING WITH IT, AND REMOVE IT FROM THE VISE ANY TIME YOU ARE GOING TO LEAVE IT UNATTENDED!

Also, with a thin blade like this, you should only grind the portion of the blade nearest to the vise - the grinder will set up vibrations in the blade if grinding too far from the vise. This can damage the blade and possibly you as well. When you need to grind farther out on the blade, reposition the blade in the vise.


Cross section of the blade blank should look something like this to start with.