CPM spec sheets

Thanks Cliff and Doc! With all the talk about 3V I thought popping this back to the top would be helpful.

Good info, I recently finished my first 3-V blade. I am not sure what happened but at a rockwell 59 I totally trashed the edge hacking on a brass bar. I will do another and use Ed's formula for the heat treat and see what happens, maybe I went too thin on the edge......I did snap the blade, cant say how it compares to other things though, I think 5160 is tougher though......

A while back I made a knife of the 10-V and it was some of the hardest to grind material I have ever tried, In the annealed state way worse than Talonite. It does however have a very snappy heat treat, I had no problem getting it up to a 68 rockwell before tempering. The customer says it is a good edgeholder but I would be skeptical about 20 times the wear resistance of D-2. Just my unscientific opinion however.........

To be precise, I just did a few measurements and its 16 times. There are no numbers listed just a chart.

What happened to the 3V blade, did the edge dent up really badly or chip out? Did you break it by prying or just hacking at the bar? How would Talonite have handled the same thing?

CPM lists a bend fracture strength of 10V as 627 ksi at 64 RC. I would be interested to see that compared to say ATS-34 or something similar as a benchmark.

Cliff, The edge bent up to the point of destruction, I wasnt hacking that hard. As I say, I am trying a different but very similar heat treat, and a little thicker edge before I make any judgements on the 3-V. When I broke the blade, I stuck it in a vise and pulled till it snapped, and I would guess it let go at about 70 degrees. I didnt use a cheater pipe, but it took a lot of force to get it to go. I had clamped about 1 1/2 inches of the tip in my vise. As far as Talonite hacking on a brass bar, I have done the same test with Talonite with no edge damage visible. The Talonite knives are flat ground, where the 3-V knife was hollow ground. I am flat grinding the next 3-V knife. I will try to take a picture of the 3-V knife and send it to you....... I havent snapped a Talonite knife off yet, too expensive!
Spec sheets added for CPM REXM4HC(HS), CRU-WEAR, and 154 CM.

CPM states for 154 CM "It has the highest attainable hardness of the corrosion and heat resisting grades". Since ATS-34 and 154 CM are very similar (what are the differences) this makes the idea of ATS-34 being noted for its edge holding quite sensible.

Is 3V supposed to be the toughest of the CPM. I was looking at the sheets and that 9V looks pretty good as well.

thanks and take care
Rob: No fair "trashing " 3V if you didn't herat treat it properly!! What's up with that?
How did you heat treat it?

RJ Martin
RJ, I am not trashing 3-V at all, merely giving my first experience with it.

My heat treat was, From cold furnace, heated to 1550, held for 15 minutes, ramped up to 1950, held for 30 minutes, quenched on my surface grinder magnet with a 1" thick piece of steel on top. (eliminates any warpage) Rc was 63. Tempered 3 times at 1050 for a Rc of 59.

I now have Ed's heat treat formula and another blade ground out of 3-V with a thicker edge that is flat ground, not hollow ground.

I appologise if it sounded like I was trashing 3-V, It was not intended to sound that way, on the contrary, I think this stuff has the potential to blow away a lot of the popular carbon steels out there now, but MY firs blade didnt work out for me, the next one will be different I am thinking.........

Thanks Mr. Stamp. You told me what I wanted to hear.

thanks and take care
I greatly appreciate robs evaluation. for we see that all the hype in the world is just that....until the rubber meets the road... by the way rob...do you always flat grind the talonite blades...and how thick do you leave it at the edge before sharpening..? the specs looked incredible for 3v...but we will see.....also..here in hawaii...rust is a real problem....humid, hot, salt spray... not a good choice for me.....
ATS-34 and 154 CM are very similar (what are the differences)

According to the Spyderco catalog, ATS-34 has 0.40% Manganese (versus 154CM at 0.50%), 0.4% Silicon (154CM has 0.3%), and has Phosphorus and Sulphur (154CM does not). So, what are the differences? What do the Phosphorus and Sulphur buy you?

Work hard, play hard, live long.

Awhile ago Walt posted a huge list of links, among them was a table of all the knife elements and what they each do. I downloaded it and of course forgot to bookmark it.

What is says it that Free Sulfur is not present in steels as it combines with manganese to form MnS (thus the more sulphur you have the less manganese will be in the steel).

Phosphorus has a powerful effect on hardenability and also has a marked detrimental effect on toughness and temper embrittlement.