This is a farriers rasp knife I made for a trade. It is a sygan dubh Scottish, or my interpretation of one anyway😁 the handle is some black walnut stained with an ebony stain. Two piece handle and hidden tang. I got a hold of a Scottish issue schilling coin and inlayed it in the handle. For heat treat always take a piece of the tang when using a file and heat it to non magnetic and then about two mins past and quench in oil, then hit it with a hammer, it will break if it just bends it didn't harden. If not hard go through the same process and quench in water if it won't break it won't harden properly and find another use for it. With these rasps I have found a 2 sec water quench then straight to the oil is a safe method that hardened