Opinion on CPM 3v

L

Larry in KY

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Hey guys, if anyone owns a knife made from CPM 3v, I'd really appreciate your opinion both pro & con. Thanks!
 
Hi Larry,

I own a couple at the moment and I cant say anything negative about the steel. What is really great about it is that it can be ground real thin and yet still retain a good amount of strength. I have an Ed Schott dagger that is ground real thin. I posted a review of Ed's Schott's camp knife and there is a good deal of info in that thread about the amazing properties of the steel. I also have Ed Schott making me a sword out of CPM 3V which I hope to get soon.

I would be curious to hear if anyone has anything negative to say about the steel, probably the best people to answer about the negative properites would be the knife makers. So far on the forum the steel has only gotten rave reviews.
 
About the only thing negative I can say is that it's not the easiest steel in the world to grind and finish. In fact it won't polish at all, but all its other qualities are just outstanding. I'm now finishing a 22" Espada in 3V and it should come in at about as many ounces. I guess the best thing I can say about it is that I just bought whole lot more.

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Jerry Hossom
www.hossom.com
 
Jerry,
I know what you mean about the polishing. My dagger was left rough--if that is the correct term and it looks good but it is not shiny. On the polished knives you can see grain lines throughout the steel, there is actually a very distinct pattern. I have heard that it isn't the easiest steel to grind and finish. Also, what other steels will you be using or will you now be primarily be using only CPM3V.
 
I am extremely impressed with its performance and how easy it is to get the edge back. All I have needed to do so far is stroke the knife on a hone steel as if you were stropping a razor and the hair popping edge is back. Bailey Bradshaw was impressed enough to use it in his Whitewing knives. The knife that I have been using is the Lightwing model. Pictures of all the Whitewings can be seen on my website.

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Chris http://www.members.tripod.com/ctexknife
 
Donna, I also use 154CM (having just switched from ATS-34 so I have some of both) and A2. They also have their roles. In field knives, a stainless steel is an asset. A2 is good in fighters and has worked well for me in swords.

But I have to confess there is just nothing quite as good as CPM-3V, at least in the high alloy steels I'm familiar with. The finish I put on 3V looks like the brushed finish on other steels; it's shiny but that is as good as I can do. I normally polish my edge bevels, but on 3V that just doesn't work. There is no visible grain in the 3V I've worked with, however. I do see grain in A2 and in ATS-34 I've gotten from Admiral Steel. 154CM is dead clear; that's why I'm switching.

I'm looking forward to trying Crucible's new super steels, CPM-3V Modified and S125V. Both are stainless and are supposed to be the hardest and toughest stainless steels ever produced. That's the positive side. The flip side is that they are supposed to be the toughest steels ever to grind.

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Jerry Hossom
www.hossom.com
 
I am surprised that there is any grain structure visible in any CPM steel, considering the flash melting (HIP/CIP) of the extremely small grain powder, which is the CPM process.

Donna; are you sure your dagger isn't AUS-8 (laughing, ducking, running for cover)??

Walt
 
Here is a CPM-3V blade I finished this afternoon. You can just see the blurred reflected image of trees and clouds. That's about as good as I can finish 3V. Certainly not rough, but not exactly a mirrow either.

img35.jpg


No grain there though.

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Jerry Hossom
www.hossom.com
 
Jerry,

Hey, that finish looks very nice!! I don't think anyone would have a problem with that finish at all, except perhaps a collector who prefers the high, mirror finish.
BTW, your grind is perfect! Thanks!
 
Walt, Jerry
My dagger doesn't show anything, the finish looks perfect because it is left rough. Now I dont know if I am using the correct terminology here. I think I'm using wrong terms. I remember Ed pointed it out to Mitchell Lake (another forumite) and myself when we were at his place. He pointed out how the CPM 3V is hard to get a mirror finish on. Maybe Ed can get on here and clafify the correct term of what I called grain lines. On my camp knife there isn't clouds and trees, there are fine, parallel lines--I called these grain lines. I have a hunch that we are on the same track here and the the differing marks are just the signatures of two differant knife makers.

Excuse my lack of correct terminology, and lack of knowledge in knifemaking but frankly I leave it up to the knifemakers who I buy my custom knives from. I just want to know how the knife will perform for my needs and what type of steel and design is best. If it doesn't live up to its sales pitch than I am going to bitch and bitch rather loudly.

Walter,
Its been a long time since we have been on the same thread together, this is beginning to feel warm and cozy and its taking me back to the good 'ole days.
 
That clouds and trees finish is much harder to achieve on rainy days.
smile.gif
If someone wants a mirror polish, they are going to have to use some steel other than CPM-3V. Crucible doesn't even rate it on the Polishability Scale. It doesn't even get a zero; it gets N/A.

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Jerry Hossom
www.hossom.com
 
Don't think of it as N/A, think of it as, "Off the Charts"!
Jerry, could you offer us a little more evaluative info? So it can't get a mirror finish. How tough is the steel? Is it the best edge holder? That sort of stuff. You know, how will it perform differently than, say, my ATS-34 AFCK?

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"Come What May..."
 
Crayola, CPM-3V is an extremely tough steel, having twice the impact resistance of A2, and about 3 times greater wear resistance than your ATS-34 blade and twice that of D2. Because of its toughness, it can safely be ground thinner (as in a much finer edge) than other steels, without fear of chipping or breaking.

In large blades it has allowed me to do things that I just wouldn't attempt with other steels. Imagine a Bowie with a 12-1/2" blade that weighs just 13 oz, yet chops through bone with ease and no chipped or rolled edges. In my mind, this is THE steel for tactical blades.

When Crucible introduces the stainless version, CPM-3V Modified, it just might be THE steel for all blades.

If I'm gushing a little here, it's because I am very impressed with 3V.

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Jerry Hossom
www.hossom.com
 
Yep, CPM3V is tough stuff. However, you are faced with the toughness / edge holding trade off. Other CPM alloys have much higher vanadium levels, with concomitantly higher levels of vanadium carbides, which will afford much greater edge holding. These alloys are not as tough, however. In general, there is an inverse proportion between vanadium level and toughness. Check the CPM site for data on this: http://www.crucibleservice.com/crumain2.htm

One quality of CPM3V which has not yet been noted is that it rusts quite easily.

Walt
 
Walt :

Other CPM alloys have much higher vanadium levels, with concomitantly higher levels of vanadium carbides, which will afford much greater edge holding.
Click to expand...

No, just wear resistance, that is not the same thing. Strength and toughness could easily be the critical factor depending on the level of stress during the cut.

One quality of CPM3V which has not yet been noted is that it rusts quite easily.
Click to expand...

According to Phil Wilson, from talking to Crucible, it is similar to D2. Have never looked at this myself, but I will. I have a blade in 3V and one in D2, and lots of others waiting for the salt bath.

-Cliff

[This message has been edited by Cliff Stamp (edited 06-15-2000).]
 
Walt, I have found 3V to have almost no tendancy to rust after heat treating and finishing. It rusts easily while I'm grinding it, while the surface is rough, but the finished blade seems quite impervious to corrosion. I don't understand why you are having a problem with it. As Cliff suggests, it is quite similar to D2 (7.5%Cr vs 11.0%Cr), and while certainly not stainless, it should be a lot better than most tool steels.

Also, the fact that 3V is twice as wear resistant as D2 argues that it holds an edge very well. Until CPM's came along D2 was the edge holding champ in high alloy knife steels. 3V is not as good as 10V or 15V certainly, but still very good.

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Jerry Hossom
www.hossom.com
 
In talking about edge holding, you also need to remember that "cutting efficiency" has a lot to do with that also. Not directly related, but if you can get a higher performance (read thinner at the edge) grind on a knife ue to it's increased toughness it will effectively hold an edge longer. I know that is not always true, but generally so.

Right now A2 is my favorite steel for this reason. When I first saw 3V in industry a few years ago, I called two makers I thought might know about it to get their opinion: Ernest Mayer and RJ Martin. either of them used it at the time, but I think Randy does now.

-Bart
 
In talking about edge holding, you also need to remember that "cutting efficiency" has a lot to do with that also. Not directly related, but if you can get a higher performance (read thinner at the edge) grind on a knife ue to it's increased toughness it will effectively hold an edge longer. I know that is not always true, but generally so.

Right now A2 is my favorite steel for this reason. When I first saw 3V in industry a few years ago, I called two makers I thought might know about it to get their opinion: Ernest Mayer and RJ Martin. either of them used it at the time, but I think Randy does now.

-Bart
 
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