CPM 10-V knife done

Rob Simonich

Big Bear
Oct 3, 1998
I just finished up a CPM-10-V knife and shipped the other day. This is an interesting blade material that I am anxiouly awaiting results and thoughts from the customer on. It was tough to work, heat treated beautifully and I think will beat 440-V easily in the edgeholding department, but that remains to be seen. I didnt have time to do much testing on it so I will be relying on the end user till I can make another knife out of the bar I have. Are you guys interested in hearing more? I wont write anymore unless you guys want to hear about it, and the customer may do some posting here. Rob Simonich

Rob - I have a CPM-10V blade that Ralph Turnbull made for me about 10 years ago. awesome edgeholding. Needs more attention on the corrosion resistance side, but not difficult for a knife person. A little harder to sharpen (doesn't like to "give up" molecules). I would interested in hearing abour performance.
How does this stuff compare to 440V as far as alloy content. Do you happen to have the the % constituents.
The chemistry of CPM 10-V is

C 2.45
Cr 5.25
V 9.75
Mo 1.30

Not sure what the chemistry is for 440V. Maybe others on the forum may know.

Edward R Schotz (SIC?) has posted that he has played with all the CPM stuff and feels that CPM420V and CPM3V are the best of the best with his vote going for the 3V. If memory serves he's even ordered mill runs from Crucible so he'll be able to supply makers with pieces. Seems I remember something about the 10V being a tad too brittle...dunno.

Obviously there is too little published about the CPM stuff other than 440V and 420V, so YES I'd like to know more. And how it compares to Talonite!


Bald is beautiful! Rub a dome for luck today!

Now I am curious. The big thing to me is edge holding. What is the best holding blade steel cpm makes? I have a knife on order with Rob in 420V. That is very a hard material to find at present. After seeing the posts on steels such as 3V and 10V I am curious which one holds it's edge the longest. Sal how does 10V compare with ATS as far as corrosion resistance. I know how bad my luck is with that steel so I wonder how the other's compare.


Tom Carey
Sal, Turnbull has been playing around with these alloys as long as I can remember, I didnt know they made 10-V that long ago!

Bob, as far as brittleness, Crucible's steel selector chart shows it with better wear resistance as well as being tougher.

Tom, 10-V is not a corrsion resistant grade, shjould be between A-2 and D-2 in that area....

Tom - I believe Rob is correct. 10 V is not a very corrision resistant steel. 5.25 Chrome is not much. Though we have not done "Q" fog testing on CPM-10V, based on the numbers, I would guess ATS to be superior in corrosion resistance over 10V. Sometimes the numbers don't tell the whole story. That's why testing is necesssary.

Rob - Not sure of the date, but Ralph made it before the Guild show moved to Orlando. Ralph might remember. Ralph is one of the early players that sparked my interest in CPM metals. (Corbett Sigman was another) He was promoting the stuff for it's toughness value a long time ago. Regarding the "brittleness" issue with CPM steels, we learned that the key was in the hardness. Most makers try to treat it like an ingot steel in terms of hardness, but the CPM materials perform better and are tougher at lower Rockewells than you would use for normal high carbon steels. Rc56/57 is about as high as you want to go with 440V. I don't know the optimum working hardness for 10V, but it's probably lower than you might expect.
I will do some testing once I receive the knife and will post my findings here. Any suggestions on types of testing? I do not have a knife made of talonite and cannot compare the two. However, I do have a Boye Dendritic Cobalt knife.
Guys: Generally, the higher the Vanadium content, the better the edge holding. However, the toughness also declines (generally). Therefore, we are again speaking about balance. CPM10V is not particularly tough. Depending on the end use, this may or not be a factor. We also should consider, how much edge holding is enough, vs. ease of resharpening? COnsidering the results my customers have had with my A2 blades, CPM3V is going to be my choice. For me, I'll take the significantly higher toughness of the 3V combined with the higher wear resistance.

Remember, most knife users don't have the spohisticated equipment (or experience) for sharpening that makers have.

Looking forward to the continued flow of data.

Yes, Rob, I'd be VERY interested in any material testing you would be able to share with us, particularly if we could get some comparative testing between CMP-10-V and 420V. I'm particularly interested in the hardness/edgeholding/toughness swap-off.
As I live in Las Vegas, what is this stuff I keep hearing about that seems to attack some knives? I think it's called 'rust', but we don't see it much here. :)


My experience with the CPM steels has been with the 440V Spyderco Military, and my 420V Ralph Krait. I liked the 440V blade better as a tool. I considered it to be roughly equal to very hard tool steel in terms of sharpening effort. Maybe the toughness isn't on a par with well tempered tool steel, but it is better than ATS-34, I believe, so that makes it a good steel for a user knife.

I find the 420V blade on my Krait to be hard to sharpen. The Krait is billed as a fighter, and it doesn't make the most versatile utility blade. As such, it sort of makes sense to have a very tough and wear resistant steel in that knife, but I wouldn't want it on a utility knife, especially if I might need to sharpen it in the field.

So my opinion about the two is:

440V - great stuff, but M-2 holds an edge about as well and is tougher at moderate hardness.

420V - tuff and abrasion resistant, superb for smaller defensive knives, but too hard to sharpen for a utility knife.

CPM3V sounds interesting. Better toughness and edge holding than A-2? That would be great for big tactical blades.