Dear sir
We use crushed stone powder, spread on a smooth wood flat to sharpen our edged tools. Crushed stone powder over the wood flat sinks in and works as a grinding wheel with embedded stone powder.it help to make a real sharp edge in tools like knife, hatchets, machetes and hawks. sharpness stay longer in this method. We never use files or grinding wheels for this purpose, as the sharpness fade away quickly.only black smiths use them, when we take tools to them.
Forgive me for my English.
Thank you sir.