I made this from an old file from finland. I grinded it with an belt grinder. I brought the blade portion up past the magnetic point while leaving the ricasso and the shaft relatively cool.and then quenched it in oil. I mirror polished it by bringing up the grit from 80,120,220,400,1200 and polishing compound. i cut the right angles on the bottom to accept where i will be putting a brass cross guard and a hickory handle. i hope to get the brass soon and work on it shortly. i will pin the rattail in the handle. Does anyone have advice on the best way to do this with what i have so far?
I subscribe to what mr.mountaineer said: do not use right angles where the blade ends and turn into the thang. Right angles makes that a weak point where the knife could break under heavy load. To do that I put holes in the file with a large drill bit, then I prefer to have a wide tapered tang.
One thing on the Heat Treat: passing the magnetic point is a weak hint you are going the right way. Let me explain: iron ( thus steel) gets non magnetic at 770°C, but most steels, due to the chemical composition, get to the austenic point between 750°C and 850°C or more, each steel has his own temperature. You should keep the blade at this temperature for 5 or 10 minutes (the thicker the blade, the longer) and then quench. Also quenching has some "tricks" you could use to maximize martensite content in the blade: Drop the temperature from (say) 800°C to 400°C in a second, then go to 200°C in 10-30 seconds and then keep the 200°C for 5 to 10 minutes or so.