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Price is$300$250 ea (shipped within CONUS). If you live outside the US, I will contact you after your order for extra shipping charges.
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Feed Back on CPM-440V
- Thread starter L.Jinks
- Start date
The Tourist
Banned
- Joined
- Dec 23, 2001
- Messages
- 2,796
It's my wife's favorite steel. So much so that I'm looking for a Kershaw Random Task. I've sharpened hers with water-stones and I don't have much trouble making it shine. She feels it cuts forever. I've heard it's a little brittle, but the worst she cuts is cardboard boxes, and while she's a slasher, she doesn't chop hard stuff.
- Joined
- May 26, 2000
- Messages
- 1,922
If you are having a custom blade made, the thing to get in stainless now is CPM's S30V. It meets 440V in edge holding at a given hardness, but is tougher (impact toughness, resistance to chipping) so can be run several (3-4) Rockwell C-scale points higher in hardness. Higher hardness means it'll hold an edge better when slicing or push cutting. 3-4 Rc points is a lot. Like at least 20% better in terms of resistance to edge wear and rolling, and perhaps approaching 30% or more.
S30V's corrosion resistance is about the same as 440V (very good). Abrasion resistance should be similar. Look for S30V at Rc60-62 to begin taking market share in the higher end products.
CPM 440V is relatively brittle compared to most any other stainless steel at a reference hardness. It therefore has to be run no higher than around Rc58 (by a custom maker). The production houses run it around Rc55-56 (Spyderco & Kershaw), mostly because they found it tended to chip out at Rc58 or thereabouts. This is unfortunate, but is a characteristic of the steel... as running softer means the edge will roll more readily.
I have found that 440V from Spyderco takes a great, toothy, wicked sharp edge, rivaling carbon steels. I attribute this to being relatively easy to sharpen (due to softness) with diamond stones, and to having a fine grain structure (characteristic of CPM steels when heat treated well). Subjectively, it holds up well cutting cardboard (abrasive), but the edge does tend to roll on harder materials or under harder use.
CPM 420V is better than 440V in every measureable performance characteristic, but 420V is harder to grind, heat treat, and finish, so isn't as popular in general, but is used by the custom makers who care enough to tackle heat treat and finish. 420V is too difficult for the production houses to grind/finish/treat, so you don't see it.
S30V should change all of this... Spyderco's Sal Glesser has already indicated their testing shows it to be on par w/ 440V at a given hardness, and that he intends to use it on certain pieces going forward (implying the heat treat is tractable for Spyderco). This is a good sign. The more progressive custom makers are finding S30V to have notable improvements over both ATS34 and BG-42, and are beginning to use S30V instead when the knive's intended use warrants the extra effort in grinding and finishing, and therefore cost.
ATS34: if it is heat treated properly, I'd rather have it than 440V. Problem is, there are two common tempering ranges for ATS-34, and one of them (the higher temp I believe) seems to produce a blade that is harder to sharpen for some reason (speculation is grain growth, so grain and carbide structure is larger, which is not good). If you own any Benchmade knives that span the time period 1996 to 2002, you may have noticed the change in character in the past few years (I did, anyway). With recent BM product, blades are still Rc60-61 per spec, but feel harder under diamond stones ... harder to get the sharpening job done. And I can't get as sharp an edge on them as I can on older knives (not sure exactly when change occurred, but I'm guessing around 1998 or 1999).
Custom makers who know how to treat ATS34 produce a fine blade at Rc60-61 for slicing type knives, and those who build bigger blades and run it around Rc58-59 (to boost impact toughness) seem to have it about right IMHO. 154CM is nearly identical to ATS34, some makers find 154Cm to be a cleaner steel overall for them (fewer rejects). ATS34 is really a good steel for moderate to good corrosion resistance and fine edge holding at Rc60-61, it's optimum point IMHO. It can rival D2 in edge holding at this hardness, and offers better corrosion resistance. Especially for bigger blades (say 6" and up), I just think another steel is worth pursuing for improved impact toughness, and S30V is really the best stainless choice now.
BG-42 is equal to, or slightly better than ATS-34 in nearly all performance characteristics at a given hardness, given an optimum heat treat. Subtly so, but better stuff. One knowledgeable user attributes this to less molybdenum carbides and the addition of vanadium for vanadium carbides, and I have no reason to doubt this. S30V is at good, to somewhat better, than BG-42 is most categories, but is apparently notably better in impact toughness.
This is a very brief overview....encourage use of search engine.
S30V's corrosion resistance is about the same as 440V (very good). Abrasion resistance should be similar. Look for S30V at Rc60-62 to begin taking market share in the higher end products.
CPM 440V is relatively brittle compared to most any other stainless steel at a reference hardness. It therefore has to be run no higher than around Rc58 (by a custom maker). The production houses run it around Rc55-56 (Spyderco & Kershaw), mostly because they found it tended to chip out at Rc58 or thereabouts. This is unfortunate, but is a characteristic of the steel... as running softer means the edge will roll more readily.
I have found that 440V from Spyderco takes a great, toothy, wicked sharp edge, rivaling carbon steels. I attribute this to being relatively easy to sharpen (due to softness) with diamond stones, and to having a fine grain structure (characteristic of CPM steels when heat treated well). Subjectively, it holds up well cutting cardboard (abrasive), but the edge does tend to roll on harder materials or under harder use.
CPM 420V is better than 440V in every measureable performance characteristic, but 420V is harder to grind, heat treat, and finish, so isn't as popular in general, but is used by the custom makers who care enough to tackle heat treat and finish. 420V is too difficult for the production houses to grind/finish/treat, so you don't see it.
S30V should change all of this... Spyderco's Sal Glesser has already indicated their testing shows it to be on par w/ 440V at a given hardness, and that he intends to use it on certain pieces going forward (implying the heat treat is tractable for Spyderco). This is a good sign. The more progressive custom makers are finding S30V to have notable improvements over both ATS34 and BG-42, and are beginning to use S30V instead when the knive's intended use warrants the extra effort in grinding and finishing, and therefore cost.
ATS34: if it is heat treated properly, I'd rather have it than 440V. Problem is, there are two common tempering ranges for ATS-34, and one of them (the higher temp I believe) seems to produce a blade that is harder to sharpen for some reason (speculation is grain growth, so grain and carbide structure is larger, which is not good). If you own any Benchmade knives that span the time period 1996 to 2002, you may have noticed the change in character in the past few years (I did, anyway). With recent BM product, blades are still Rc60-61 per spec, but feel harder under diamond stones ... harder to get the sharpening job done. And I can't get as sharp an edge on them as I can on older knives (not sure exactly when change occurred, but I'm guessing around 1998 or 1999).
Custom makers who know how to treat ATS34 produce a fine blade at Rc60-61 for slicing type knives, and those who build bigger blades and run it around Rc58-59 (to boost impact toughness) seem to have it about right IMHO. 154CM is nearly identical to ATS34, some makers find 154Cm to be a cleaner steel overall for them (fewer rejects). ATS34 is really a good steel for moderate to good corrosion resistance and fine edge holding at Rc60-61, it's optimum point IMHO. It can rival D2 in edge holding at this hardness, and offers better corrosion resistance. Especially for bigger blades (say 6" and up), I just think another steel is worth pursuing for improved impact toughness, and S30V is really the best stainless choice now.
BG-42 is equal to, or slightly better than ATS-34 in nearly all performance characteristics at a given hardness, given an optimum heat treat. Subtly so, but better stuff. One knowledgeable user attributes this to less molybdenum carbides and the addition of vanadium for vanadium carbides, and I have no reason to doubt this. S30V is at good, to somewhat better, than BG-42 is most categories, but is apparently notably better in impact toughness.
This is a very brief overview....encourage use of search engine.
- Joined
- May 26, 2000
- Messages
- 1,922
I didn't answer part of your question.
I am not a maker. So anything I say on workability and finishability is 3rd hand at best.
440V is purportedly harder to grind and finish than is ATS-34. I think it is notably more expensive to buy also. Therefore, I can't see many (any?) reasons to use 440V now compared with ATS-34, 154CM, BG-42, and especially now with S30V's advent.
- Joined
- Sep 17, 2001
- Messages
- 1,218
My experience with CPM440V is kind of mixed.
I own two 440V knives, a Spyderco Native LW and a Spyderco Chinook. Both are of exceptional quality for their corresponding prices and I like both quite a bit.
440V holds a respectable edge for a LONG time, my experience with it is that it can go up to 6 months of total edge negligence from my relatively medium use and still maintain a decent edge. But be warned, if you let it dull that badly, sharpening it will be quite an effort (particularly if you lack diamond stones like myself). I can recall the temporary carpal tunnel syndrome I developed from sharpening my Chinook on my 204 Sharpmaker for a good 50 minutes.
So the moral of the story is 440V is a tough, long-lasting edge, but I suggest you keep it touched up to save yourself lots of effort later, you'd also do well to obtain some diamond stones for your own convenience, but they aren't necessary.
For a quick reference, I said my 440V edges lasted up to 6 months under my usage, for perspective i'll share with you about how long edges from other steels last for me.
0170-6C - 1 month (hard use)
420HC - 3 weeks
440A - 1 month
ATS-34/154CM - 3 months
AUS8A - 2 months
440V - 6 months
As you can see, 440V has a BIG hike in lasting power, so it's probably worth the leap.
Final notes: I am not particularly great about keeping my knives touched up, and as such, I'd be a bit more hesitant to buy 440V knives in the future because of the penalties of my negligence, however, I hardly consider a 440V blade to be prohibitive when I'm considering a knife.
440V is a karmic steel, you kind of get what you put in.
I own two 440V knives, a Spyderco Native LW and a Spyderco Chinook. Both are of exceptional quality for their corresponding prices and I like both quite a bit.
440V holds a respectable edge for a LONG time, my experience with it is that it can go up to 6 months of total edge negligence from my relatively medium use and still maintain a decent edge. But be warned, if you let it dull that badly, sharpening it will be quite an effort (particularly if you lack diamond stones like myself). I can recall the temporary carpal tunnel syndrome I developed from sharpening my Chinook on my 204 Sharpmaker for a good 50 minutes.
So the moral of the story is 440V is a tough, long-lasting edge, but I suggest you keep it touched up to save yourself lots of effort later, you'd also do well to obtain some diamond stones for your own convenience, but they aren't necessary.
For a quick reference, I said my 440V edges lasted up to 6 months under my usage, for perspective i'll share with you about how long edges from other steels last for me.
0170-6C - 1 month (hard use)
420HC - 3 weeks
440A - 1 month
ATS-34/154CM - 3 months
AUS8A - 2 months
440V - 6 months
As you can see, 440V has a BIG hike in lasting power, so it's probably worth the leap.
Final notes: I am not particularly great about keeping my knives touched up, and as such, I'd be a bit more hesitant to buy 440V knives in the future because of the penalties of my negligence, however, I hardly consider a 440V blade to be prohibitive when I'm considering a knife.
440V is a karmic steel, you kind of get what you put in.
- Joined
- Jun 9, 1999
- Messages
- 4,729
My personal experience with 440V has been with a Kershaw Boa. I like it a lot, but I will agree with other comments about it being hard to sharpen. I did mine on an Edge Pro, and the initial sharpening took about an hour and a half as I remember. It may have been longer. The upside to that is that it took an absolutely beautiful edge. Right after I recieved the knife as a gift I went to Basic Training with the Army for two months, then to Advanced Training for six more months, so I didn't get to use the knife for a significant amount of time for about eight months. I've used it more recently, and it's held up fairly well. I had to resharpen it when the edge rolled a bit, but with the bevel well established resharpening took only a few minutes. I've also noticed it has very good corrosion resistance for moderate use. I haven't used it in any extreme circumstances, so I don't know how it would hold up against saltwater, but it holds up fine under everyday corrosion.
In conclusion I'll say that I would reccomend it, or at least I would reccomend Kershaw's heat treat. It's definitely a cut above everyday steels.
In conclusion I'll say that I would reccomend it, or at least I would reccomend Kershaw's heat treat. It's definitely a cut above everyday steels.
- Joined
- May 26, 2000
- Messages
- 1,922
Yikes. Some of you guys desperately need to buy diamond stones or a motorized grinder w/ hard felt sharpening wheels. A full reprofiling with even 1/2 new stones takes maybe 10-15 minutes tops. With a grinder, done judiciously and while dunking the blade between passes, maybe 5 minutes.
rdangerer summed up the strengths and weaknesses of 440V extremely well in his first post. I would note that I have a Spyderco Military in 440V, with the lower RC, and the points of the serrations do tend to roll, even when cutting materials such as wood. I just knock off the rolled parts with a swipe on a DMT stone.
I'd also add that I really don't care for ATS-34. I find it hard to get a good edge on, it rusts almost as readily as non-stainless steels like D-2 (especially when bead-blasted), and it doesn't hold its edge particularly well compared to either the newer "supersteels" or the older non-stainless steels. I do like 3V, and I'm looking forward to trying out S30V at some point in the future.
Right now, D-2 and INFI are my two favorites, for their ease of sharpening, stain resistance, and good edgeholding. D-2 seems to take a toothier edge, and INFI a more polished one. INFI will also roll if you hit something hard (like a pebble or nail), which I think is preferable to chipping. I don't have any choppers in D-2 so I can't comment on what it does under similar circumstances.
I'd also add that I really don't care for ATS-34. I find it hard to get a good edge on, it rusts almost as readily as non-stainless steels like D-2 (especially when bead-blasted), and it doesn't hold its edge particularly well compared to either the newer "supersteels" or the older non-stainless steels. I do like 3V, and I'm looking forward to trying out S30V at some point in the future.
Right now, D-2 and INFI are my two favorites, for their ease of sharpening, stain resistance, and good edgeholding. D-2 seems to take a toothier edge, and INFI a more polished one. INFI will also roll if you hit something hard (like a pebble or nail), which I think is preferable to chipping. I don't have any choppers in D-2 so I can't comment on what it does under similar circumstances.