Soft 440C.

P.K.Hansen

P.K.Hansen

Joined
Aug 8, 1999
Messages
402
I recently bought some factory blades made in Japan, which are supposed to be 440C.They come hardened and ready to use, but I can drill holes into them without any problems and that made my wonder.Does anybody know these blades? They have the following names:
Santa Fe, Navajo Skinner, Sioux Hunter, Silver Moose, Kiowa Hunter, Bowie Hunter, Tanto.
Are they worth a good handle or should I face the fact that these blades are junk.
 
I have had people bring me these blades so that I could try to "reharden" them. I found that the tangs where soft but the edge and most of the blade was hard, around Rc57-58!
Several of them had just the right amount of hardness going through the first inch or so of the tang. Others were too soft at the ricasso area and about an inch up the blade. They were no good. The ones I checked were the same names probably from the same supplier....I would say, of the ones I checked, about 3 out of 10 were not worth handles. Are you able to drill through the blade area as well and the tang????

[This message has been edited by Dr.Lathe (edited 10 September 1999).]
 
Just whip out your handy dandy pocket sized rockwell tester and give it a test. (just kidding) if you do have access to a hardness tester somewhere by chance, I would be very interested in how they test out. Sort of a qc on the kit makers for those of us out here who do kits sometimes.
 
I haven't tried to drill the blade, only the tang.Didn't want to ruin the blade if they were OK, but if you want to know I'll give it a try.
 
Sounds like they're differential heat treated. If so, that's pretty cool. I don't know why the catalog wouldn't mention that. I have a catalog that, coincidentally, sells those exact models. I'd go with a file test rather than trying to drill it, just to make sure you don't waste a blade. It may only be hardened on the edge.

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Oz

"When your work speaks for itself, don't interrupt."
- Henry J. Kaiser
 
I'm back.
I just drilled 4 holes in the skinner, starting about an inch from the ricasso moving towards the tip.NO PROBLEM.
I used a normal HSS drill. I guess that says a lot about that blade.
T.J. These are the only ones I've ever seen that are this bad.I cannot believe that a US blademaker would sell stuff like this, he has a name to loose. For kits I normally buy blades made in Norway - that's really great material, but I prefer to make my own ones in either 12C27 or ATS-34.No more from Japan.
 
You people keep me on my toes.
Okay Osbourne I just gave the edge a few strokes with a file - soft as butter.
Anybody else want me to try something new?
Just kidding - it seems that this blade is not hardened anywhere, and if it is, it was done really bad.
So - what to do ? shall I try to reharden or through it away.
 
Seems like you have a great piece to practice heat treating on, I don't see why not, as long as you have a heat source. Heat it up to non-magnetic, then quench it in light weight motor oil or olive oil and see what happens. It'd be fun, if nothing else. Warm up the oil to around 120-140 first, and be careful, you'll likely hit the flash point of the oil, so it will burn for a moment, but it usually self-extinguishes.

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Oz

"When your work speaks for itself, don't interrupt."
- Henry J. Kaiser
 
the higher alloy knife steels should NEVER be selectively hardened....and Im not sure its possible to do it properly....the only way i can drill thru ANY knife that i sent to paul bos is with a carbide drill....its hard to believe that anyone is doing this.. as the tang needs to be super hard to prevent wear...in any type of locking folder. could it be possible that these knives are laminated steel with hardened 440c in the middle???????

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http://www.mayoknives.com


 
Even if they were laminated, shouldn't I still have a problem when trying to drill through the hardened middle?
As far as I know they are not laminated.
 
You could find out if it's a laminate by etching it. Stainless will normally only laminate with something with less chrome in it, so it would etch at different rates. The 440 would hardly etch at all, so you can also test the alloy that way. A little bit of solder flux in one of those drilled holes would let you know in about ten minutes if Tom's hit the mark.
Have you tried a spark test, to verify composition? I don't know what kind of shop you have.

------------------
Oz

"When your work speaks for itself, don't interrupt."
- Henry J. Kaiser
 
My shop would make you guys leave the house screaming.I make my blades on a 40$ beltsander, but it gets the job done.I'm saving for something better.That sparktesting is not something I do - I dont know how.
 
I wish I could see a spark on that steel. I'm wondering if it's actually 440C, or maybe something else. In any case, it couldn't hurt to try to heat treat it yourself, just on the junked one. If you get it to full hardness, and it's still that soft, then it's not 440C, and you should get your money back.
That's an option I'd be considering anyway, though.
------------------
Oz

"When your work speaks for itself, don't interrupt."
- Henry J. Kaiser

[This message has been edited by Osbourn (edited 10 September 1999).]
 
Since I got them rather cheap (10$ each),I'll not try to get my money back, but I hope others are warned now - if you want quality,dont buy those blades.I will finish these knifes anyway, but I'll not use first grade materials, and I'll not sell them. They will be hung on the wall in my gunroom.
 
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