tungsten carbide knife

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jerry knox

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I tried zirconia, jasper, and glass first, and they were all nice, but dulled almost as fast as steel due to chipping and then were much harder to sharpen.

I've finally gotten a tungsten carbide (WC) knife to work which is good enough to deserve the name, and I love it. It's been my EDC for two months now, and is showing no signs of damage despite considerable edge abuse. My only complaint is that it's not quite shaving sharp, but that's only waiting on me being able to afford the >1 micron diamond lapping film, then life will be good.

I have used it to score and cut glass, remove a burr from a concrete block, whittle down a fiberboard shelf, and of course, trim innumerable threads, hangnails, and corners of pieces of paper;)

As for sharpening, it's not fun, but you only have to do it once:D

I am too poor to attach pictures, but if anyone's interested, I can describe it and/or post them on Facebook.

The handle if what A.G. Russell calls a "funny folder". The blade is a pointy sheepsfoot with a straight edge (due to the original shape of the WC blank).
 
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Post pictures on photobucket.com and link them here. I'd be interested in seeing this.
 
I sharpened tungsten carbide for a living for over 12 years......


It is as brittle as glass..........are you using some other alloy?
 
David, I am actually inlaying slips of WC I grind down from solid carbide mini blades (for the "woodrazor") into steel and aluminum blade bodies. The premade blades have too much carbide width to allow drilling holes for making folding knives. I do, however plan to use one to make a belt knife soon.

Tom, I agree that the carbide is much more brittle than plain steel, but it is orders of magnitude tougher than zirconia. I have not done any hacking with it, but the way it is used in the planer, it has to resist SOME impact. I haven't managed to chip it, even the very fine tip, but I would definitely not pry with it.

For example, I cannot sharpen the zirconia on a diamond stone because the edge micro-chips against the hard surface. I have to sharpen those on an eraser with SiC finishing sandpaper stuck on top. But with the WC, I can grind them on a bench grinder with no chipping and then finish them on a diamond stone. I plan to get the diamond lapping film so that I can get a super-fine polished edge, which seems to make a huge difference with ceramic cutting tools (they don't really have "teeth" like steel). So far I have been using the SiC paper, but, being about the same hardness as the WC, it wears our really fast, and doesn't cut much, sort of like hand polishing a diamond...
 
Jerry,

To my ears, it sounds like a tungsten carbide knife is basically good as a novelty, i.e. there aren't other knives out there (or very few) made from it. But aside from that, can it out-perform any of the more commonly used steels in any way? If yes, could you please elaborate?

And if you have not done side-by-side tests, could you please offer your opinion and a basis for it in regards to those same two questions?
 
Hi, OTE.

I would say that WC probably falls solidly in the "novelty" category. For almost any given use, I can think of a steel substitute that would work just as well (unless you want to "cut" glass, that is;)).

But you just can't beat the "cool factor" of carbide, in my mind, and I also like that I can use it to sharpen my other knives (shaves them like aluminum).

Finally, I don't have much of a setup for knifemaking, and this allows me to have a superhard knife without any heat treating, and for about $5 per blade.

I would love to see a really high-end version of this concept, by the way. I'd be generous, if anyone wanted to make them, and just take serial number 001 ;)

P.S. it is also pretty close to the best in heat resistance, I think.
 
so sounds good for a low abuse folder what is the hardness anyway i'm guessing around 77 Rc as for the novelty its allot like damascus (wootz and pattern weld)
 
i have a farid with a blade out of T-1..I think it is around 90RC

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standard.jpg
 
First, two shots of the group of WC prototypes in timeline order. The smallest one is the one I was posting about.

http://i220.photobucket.com/albums/dd139/JKnox0526/group_closed-1.jpg
http://i220.photobucket.com/albums/dd139/JKnox0526/group_open_2.jpg

You can see thr progression, including my handle making. I started by fitting blades into existing handles of knives I had messed up, and have finally made my own handle! #1 & #3 have aluminum blades, #2 & #4 are 303 stainless. The longer blades are all ~3" long (the length of the carbide slip).

Next, the blade of the knife in question

http://i220.photobucket.com/albums/dd139/JKnox0526/blade_2.jpg

From the finish, you can see that I haven't been too easy on this knife. It started out as mirrored 303 stainless (blade and sheath) and satin 6061 aluminum ("harp"). The carbide, though is as shiny as it started, and nick free.
 
wow. HRc 90 is SUPER hard! What is T-1? I don't see it on Professor Google...

edit...

Oh, I see. I don't think T-1, or anything, can actually get much above HRc 70ish. I think above that you have to use a different scale due to the properties of the rockwell testing apparatus.
 
Nice emerson knockoff by farid there!!!!!:(


If you have (or have access to) a good variable speed belt sander, you can buy diamond grit sanding belts, they cost about $80......I think Trugrit can get them (I have never gotten any but Mike Irie told me he used them for finishing S30V for many years)
 
Silica Carbide belts will work Carbide. (WC) albeit S l o w l y. also I use a 4"x106" glass grinders wet belt set up to work it. the wet set up allows you to work the steel with out it heating up :D I use it to touch up lathe bits once in a while. you can get wetbelt silica carbide and diamond belts at CRLaurence.com

Jason
 
Thanks for the tip, Tom.

I do have a belt sander. I think I'll have to check that out. I'd like to be able to pregrind my blanks for flint knapping too, and diamond belts should do all of the above nicely.

Thank you too, Jason. I know SiC works, and the finish is pretty good, but I hate using up the media so fast. One good pass, and the belt would be pretty well exhausted. I'll go see though. If the price is low enough, I might not mind destroying them...
 
Good to see you in Blade magazine. (old thread, I know). How did you attach the insert to the aluminum blade?
 
I read that Tungsten carbide has a Rockwell C hardness of 72. Hitachi ZDP-189 steel is often hardened to 67 HRC. Vanadium carbide Rockwells at 82. SiC, ZrO, and ZrC are much harder.
 
I made a knife in the same manner as the OP, using a carbide tipped planer knife. the geometry is thick, and I cant get it supper sharp, but it works ok I am also in the middle of a project with a custom formed piece of WC, in a tougher grade, ill let you know how it turns out.
 
I had a teacher who had a knife that was TC on one side of the blade only, allowing for sharpening the steel side very finely, while doing what she could to the TC side. It got and held a remarkable edge. This was in 1961.
 
Gingerman said:
I had a teacher who had a knife that was TC on one side of the blade only, allowing for sharpening the steel side very finely, while doing what she could to the TC side. It got and held a remarkable edge. This was in 1961.
Click to expand...

This thread was last posted to in 2011. Thank you for your support.

Best Regards,

STeven Garsson
 
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