New alloys; hot or hype? (advanced class)

We are all using very relative terms here. For example 425 series stainless will take a razor edge fine but you have to use a very high bevel (like 25 degrees) on a thick edge or else it will roll very quickly. Anyway, in order to try to quantify things a bit lets see if we can't bring some numbers in.

Cobalt how low of an angle are you grinding the edge on the Stellite knife and how thick is the blade just behind the bevel?

What I am betting on is that if you took a CPM 440V knife and a Stellite/Talonite knife and made them really thin at the edge (about .01 of an inch) and then put a very low bevel on them (less than fifteen degrees), the Stellite/Talonite blade would roll much quicker than the 440V one because of the soft Cobalt matrix.

Now if you had the edge much thicker and made the angle much higher the edge is not going to roll so abrasion resistance becomes a much higher factor in edge holding and the Stellite/Talonite blades might pull ahead. Note however that these blades will not cut nearly as well as those with the thinner profile.

I can't wait to get some of this stuff for myself.

-Cliff
 
The blade is flat ground 5/32 1.4 inch wide with a 20 degree bevel per side now. I'm not going to argue that it won't roll the edge when made thin, but on the other hand it continues to cut far longer than any steel. And also, I don't consider rolling an edge so bad when you compare it to the alternative of chipping an edge and having to grind away material to restore it. But with the angle I put on it, I'm not worried about rolling the edge on light duty. If my blade hits something hard it may roll, but I can restore it fairly quickly. With 440V or the like I just made a sigle tooth serration. I would say that on thin light work knives and pocket knives, 440V and other hard steels may be ok, but for a utility type knife, I'll take a little less edge retention and more toughness.

Don't get me wrong, I love 440V and 420V for folding knives, especially when made in 5/32 inch thickness like the spyderco military, to give it that extra lateral toughness. But on a fixed blade i'll take a softer steel like A-2 or similar or even a stainless damascus. Thats why I originally brought up the idea of using a 440V/420V damascus. You get the stain resistance and the lateral toughness. Reduce the edge rockwell to around 56 and you got one hell of a utility blade. If someone is already doing this, then that would be a good way to go.
 
I guess that the main consideration in choosing the ultimate alloy for knives, is what we would expect out of it. Everyone seems to have differing opinions on the performance they seek. Hard edge that may chip, softer edge that will roll and need more sharpening, blade that will bend before it breaks, or a blade that will snap instead of bending. I'm the prybar theorist. I prefer a blade that will bend instead of snapping and an edge that will roll instead of chipping. I undertand that with a blade that snaps, you can still use the knife because it is straight, albeit a little shorter(or a lot shorter). But I can straighten out a bent blade. IMHO
 
first of all let me state that i am not trying to start an argument...with that i will say that i was never very impressed with stellite...other than the fact that it didnt have any iron=no rust at all....butch winter told me he had a small fillet knife out of it and broke two inches off the end without too much effort.....and one other thing....i can sharpen a knife like you wont believe...in 1990 i won the cold steel best combat knife award at anaheim and lynn said my knife was the sharpest one entered...there were 125 knifemakers there... so i have tried and tried and tried with stellite...it doesnt impress me as a great knife steel...i have never tried talonite.....but i am IN LOVE with 440v and am about to make some knives out of 420v... keep you posted.....
 
ok sports fans...i went out to my shop and dug out my bg42 data sheet out of my extensive files (actually a big pile of trash under a big pile of knife and gun magazines and gun lists) its make by latrobe steel co..it says "LESCALLOY BG-42 VIM-VAR high performance bearing steel a high performance cr-mo-v alloy for aircraft gears, ball screws, bearing blah blah blah, typical analysis carbon 1.5 si .30 mn .50 cr 14.5 mo4.o v 1.2 there are three pages after this...i cant type that fast...go to their web site and they will fax it to you. ps latrobe is owned by timken bearing co..best way to find it is to go there first.
 
Well, Tom, it sounds like the type of edge you can put on a knife is way beyond what I can do. Therefore, the difference in my sharpening is not as noticeable as it is with yours. Also, Rob Simonich mentioned that the stuff sharpens differently than regular steel. Out of the several knife makers I have talked to about sharpening this stuff you are the first that stated he cannot get a good edge on it. I know Mike Franklin has no problem putting an edge on 6K and he was using it in the 70's. Carson has no problem with it either. I have no problem with it and I don't even know what I'm doing. Walt, Bob and Rob, do you have any problems sharpening your stellites or talonites?

Ah, the filet knife that broke. Well with 2.2% carbon, I'm sure that feat could easily be repeated with 440V or 420V. Actually, I think Rob Simonich recently tried putting all his weight on a piece of fairly thin Talonite with no noticeable effects. Actually the Charpy impact value for Stellite is 65 ft. lb.'s which is way beyond either 440V or 420V. I'm sure Talonite is right up there also. So on paper at least Stellite/Talonite is to 440V/420V as 420V is to ATS-34. There just is no comparison. I can live with what I consider a very sharp edge when the material can hold that edge for so long. Even if that edge is not as sharp as a razor.
 
i didnt say i couldnt get it sharp....just that it seems to roll over fairly easily and that...mostly....i wasnt that impressed by it as a knife steel....it worked great...a lot of my customers were super happy with it...seemed to me to take a mediocre edge and hold it for a very long time....it costs $100 per lb/// had to drill it with carbide drill bits.....took forever to grind.... and even longer to get it to look nice....i made a bunch of knives out of it...i still have a bunch...i bought 15 lbs in the beginning//at one hundred dollars per lb...what i am saying is totally my personal persuasion... not trying to talk anyone out of using it or getting any.....i am way more impressed with the new particle metalugy steels....
 
Tom, actually the cost of the stuff is were I completely agree with you, and this goes for both the Talonite and the Stellite. The cost per pound is up between $160.00 and $200.00 depending on the thickness. Also if you get a large batch you can drop this down, but who has $5,000.00 floating around with nothing to do.

Grinding is another sore point with the stellite, but the talonite is reportedly, easy to grind.
 
Tom those stellite knives you made and have a few left, are there pics or specs anywhere on the net?

-Cliff
 
Regarding Butch Winter and stellite, note that in the 5/99 TK he gives a generally positive review of the Boye dendritic cobalt folder. Although the article is slanted towards the "dendritic" qualities, he states, "Cobalt is noted for its ability to give strength and hardness to the alloy. It also intensifies the individual effects of the other elements when used in complex steels."
 
as i said before...im no metallurgist..

[This message has been edited by tom mayo (edited 19 March 1999).]
 
as i said before...im no metallurgist...only know about cobalt from the drill bits i use.. they are quite a bit more brittle than the hss ones...also..its a main ingredient in carbide...which is a brittle as glass... but that is another story....dont have any more stellite knives...just some pieces left. however if you would like a knife out of it i could take care of that for you...check out my site at www.mayoknives.com to see my styles...check the price list...and add $100 for stellite. that would be hand satin finish and every knife comes with a nice sheath that i personally make...hand fitted to that knife.. aloha....
 
Holy Smokes! This thread is getting interesting indeed! I didnt post anything about Talonite earlier for a couple reasons, first this is a steel thread, Talonite is not steel, and second, I was awaiting results on some feild testing. What I am going to do here is start another thread about Talonite, wont take so long to load either!

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www.simonichknives.com
 
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