farrier rasp HT Q's

J

Jason Fry

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Jun 5, 2008
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I'm working on a threesome of knives from farrier rasps. They're Save Edge brand, but unknown steel that sparks as high carbon. They're currently annealed. I've got them about ready to HT, and I must admit that I'm plenty nervous about all those teeth marks and stress risers/cracks. I do my HT in a charcoal forge with an oven style brick cover. My plan is to normalize two or three times, then quench. I have done enough knives in this setup that I can soak them a little without overheating. Quench medium is vet grade mineral oil, and I usually warm it up to 100 or 125 degrees. I usually do a full quench followed by an oven temper at 425-450, times two. Other than normalizing and then not overheating going into the quench, is there anything else I can do to lessen my chances of cracking?

Just for kicks, here's a pic of the knives so far. Nothing to judge scale by, but these are all 11.5 to 12 inch OAL.
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Those are some bad @$$ looking knives! The middle one though looks like the pin holes are WAY low... oh wait I see you have some up top to.. n/m :D
I'd imagine they're made out of atleast 1075 -1095, What is your edge thickness? I hope it's atleast .050" to help prevent the dreaded PING!
 
I just did some googling (is that a word) and saw a bunch of knives on here by a Mr. Wilson from farrier rasps. Some of them claimed to be edge quenched. I did leave the edges a bit thicker than I do on my usual 1080. Here's a better pic of the pin setups. They're close, but I couldn't get the drill to put them exactly where I wanted them because of the teeth.
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MikulMorris makes some file and rasp knives he's on the forums if you go to the fixed blade for sale area he has a few there now. you might email him to see what he does.

Jason
 
Here's one I just completed and sold....I had the same questions and doubts. I annealed it as you did, and ground it to shape, leaving the cutting edge a little on the thick side for ht/temper. I heated in my forge till it was non-magnetic and then edge quenched it in Brownell's Tough Quench heated to 130 degrees...everything came out fine and she finished up perfectly.
FileBowie2.jpg

FileBowie.jpg
 
Nice one, godogs. I've talked to Mikul Morris several times. He takes his files and rasps and tempers them at 450 to 500 for two hours then grinds them. That's the other good way to do it, instead of annealing/hardening/tempering.
 
Thosea are all nice! Make sure to post the finished products.:thumbup:
 
Generally you can treat farrier rasps like 1095 to heat treat. The Save Edge brand is good as is Belotta. Edge quench is fine, but I like to get the file marks ground off before quench. I just finished up 3 from rasps that I forged last weekend and they all came out well. Annealing before stock removal is sure the way to go. Mike Wilson does some of the best work from rasps that I've seen.
 
I follow more or less the same process as you do and I haven't had any problem with cracking. I have had a bit of trouble with warping, however. Your normalizing process should alleviate this however.

I usually grind off as much of the high spots from the rasp as possible, though I do like to leave the pattern. This seems to help quite a bit.

Andy
 
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