what do you think of cpm440v ?

M

modoc

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Nov 27, 2003
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I have a Spyderco Military with a cpm440v blade and wanted to know what people think of this steel. I heard Spyderco is no longer using this steel. Any ideas as to why? What are they using in the Military now? Overall I like the knife; good handle shape,nice and thin so it fits in the pocket well,light for its size,and a simple useful flat ground blade.
 
CPM440V (now known as S60V) is an excellent steel, however, S30V from all accounts is a better steel that is available at a similar cost, so Spyderco is now using it for many of their knives, including the Military. I have a Kershaw Boa in S60V and have used a few pass-around knives in S30V and have found that S30V takes a much finer edge than S60V. S60V takes and holds a great slicing edge, but because it must be left fairly soft (54-55 Rc) in order to prevent chipping, it can be deformed by impacts with hard objects, like staples. S30V can be hardened to 59-60 Rc without chipping, and so is more resistant to impacts and holds a fine edge longer than S60V. S60V has been practically abandoned by manufacturers and custom makers in favor of S30V.
 
Well said, Roadrunner.

I don't care for it. I had a hard time getting a fine edge on it, and I haven't ever had trouble with any steel before. I used diamonds, but still had trouble.

There is a place for it, no doubt, but that place isn't at my house.
 
That's right, I forgot to mention it's tough to sharpen. My Boa sharpened up very nicely on my Edge Pro, but it took a while and I wouldn't want to try it with anything else.
 
My impression is that most manufacturers harden S60V (440V) to more like 58-60 HRC. I believe my Boa is around 58. At the higher hardness levels S60V is prone to chipping if used too hard, but it holds an edge forever. Nice stuff! :)

--Bob Q
 
I think he's right in that Spyderco is leaving their S60V at around 56 Rc, lowered a couple of points from where they put it initially. They had better luck with it softer like that, according to Sal.
 
I think one of the reasons CPM-440v is losing favour is that it can be a real bear to sharpen, the same reason Chris reaves moved from BG42 to S30v.

Personally I really like 440v, once sharpened it holds an edge forever (almost) :D
 
The problems with sharpening are mainly due to the lower hardness. Highly alloyed carbides in a soft steel is the worst combination for propogation of very persistant burrs.

-Cliff
 
I just about went nuts trying to sharpen a 440V Military, because the burr was flopping back and forth, and I was dulling the edge when I cut it off at a higher angle. I'll keep trying, though.
 
For that situation you need the most aggressive stones possible, so make sure they are cleaned or freshly lapped and that the contact surface is very wide, the corners of rods for example would be very poor choices. If a really large burr develops you are in general better cutting it off and resetting the edge with a coarse abrasive.

-Cliff
 
Personally, I kind of like 440V, even at Spyderco's RC. Sharpened with fine diamond, it has a very aggressive edge and holds it well. Haven't had any trouble with sharpening either.
 
What is the difference between T440V and CPM440V (S60V), if any ? Is T440V just an older reference to S60V or is it a different steel ?
 
Well, I don't agree with everything that's been stated here, but, if you're having trouble getting the burr off the edge, you should try stropping on the back of an old belt with a green chrome compound rubbed into the belt.
BTW, in my experience, a tenacious foil edge is an indicator of a blade with good toughness and wear resistance. 3V and S30V both have tenacious wire edges.
 
rj martin :

in my experience, a tenacious foil edge is an indicator of a blade with good toughness and wear resistance.
Click to expand...

A high ductility and wear resistance will increase burr formation, but technique plays a large part as well, too much force, non-aggressive hones, weakened or otherwise damaged edges all induce large progressive burrs.

-Cliff
 
Cliff: Yes, I agree with your statement, but, I am referring to a normal, minimal burr produced with sharp abrasives and the correct sharpening technique.
 
The debate over which is better S30V or S60V will go on forever I think.

S60V remains as one of my favorite steels for a knife blade, never had any problems sharpening and it holds an edge for a long time, at least as long in my opinion as S30V even though it may chip easier.

If you ever want to see a steel that is a B***h to sharpen try a blade in S90v.

I think S60v and S30v along with BG-42 are just about perfect in all regards as steels to be used in folding knives!
 
440V is a good steel IMHO. I did have a lot of problems sharpening it until I bought a diamond stone. If you never let it get very dull, you can do all touch ups with the white sharpmaker stones.
 
I changed over to the S30V version of the Military a couple of months ago. I wouldn't even consider going back to the 440V version at this point. Spyderco's heat treatment of S30V is absolutely superb. I have experienced none of the sharpening problems on my S30V model that I had with the 440V version, and haven't noticed any drawbacks to the change in steel.

The S30V Military is the most functional tactical folder I've had the pleasure of using.
 
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