CPM-20CV: Tough Enough?

M4 has better edge stability and toughness. M390, 20cv and 204p are the same and they don't have high toughness at all. I've seen many of 20cv damaged blades before because people think it's a tough steel when it's not. Zt also make there 20cv at 62hrc which the higher you go up the hrc range the less tough it it.

Great steel for what it's made for but not toughness.

M4 will patina easy but rusting may take a bit longer than other high carbon steels. Coatings do not protect anything from corrosion. Oil the blade and keep dry when done and you won't have issues. A little patina never hurt anyone.
 
craytab said:
Absolutely not true. I guess all the knife and gun manufacturers who use coatings as a rust protector don't know what they are doing :rolleyes:
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Ive read many of posts here about it. Spyderco said it doesn't also.
 
Babboonbobo said:
What did all this cardboard do to you all???
There’s a lot of cardboard cutting going on!!!
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I live in the middle of nowhere and everything comes in a box to the door. Cardboard threatens to overwhelm the house, like on that Hoarders show, unless I cull it nightly.
 
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My experience in context...

Knives:

ZT 0609, CPM 20CV, .12” thick stock, factory edge.

Olamic Wayfarer 247, M390, .14” thick stock, factory edge and later took the edge to 15 dps with a 17 dps micro bevel, stropped to just short of a mirror polish.

Use:

Retail environment. Mostly cardboard, zip ties, plastic straps, and plastic packaging. Also occasional oddities like canvas, thick rubber, etc. The zip ties are typically cut while taut between items, or when backed by hard plastic, not harder material. Most cutting is done without a backing surface. Cardboard is often double wall. Stabbing into panels to get a start isn’t super common, but does happen enough to test a tip and keep me from buying a WE Wasabi (cry).

I love this damn steel. It begs for an aggressive edge, holds it well, and hasn’t chipped out at all.

I’ve stabbed through a rubber sheet with the Wayfarer to start a cut, discovering a soft metal backer to it. No deformation to the tip at all (tanto blade btw). The reduction of impact from the rubber drag and the softness of the metal backer likely helped with that, but I did hit it fairly hard.

I’ve intentionally avoided much maintenance on the 0609. If I recall correctly, it has only received a few passes per side on the Sharpmaker’s white rods.
 
Mo2 said:
Ive read many of posts here about it. Spyderco said it doesn't also.
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Wrong again. Go read the spyderco catalog. It says dlc helps with corrosion resistance. Many other manufacturers say the same about various coatings. Lastly, I'm not just repeating misinterpreted or missinformation I read somewhere on the internet, I've got lots of actual first hand experience with various coatings helping to prevent corrosion.

So before you post a video trying to counter my experience and what most expert manufacturers say, get your facts straight.
 
I'd like to clarify something about my post above: I've had some M390/20CV/204p that was chippy (from ZT and Benchmade) and others that were just fine (Spyderco, Microtech, WE, Hinderer). Microtech's in particular has been very impressive. I just thought I'd share that sometimes, and from some companies, this alloy class might be inexplicably chippy, and it's really annoying when it is.
 
craytab said:
Wrong again. Go read the spyderco catalog. It says dlc helps with corrosion resistance. Many other manufacturers say the same about various coatings. Lastly, I'm not just repeating misinterpreted or missinformation I read somewhere on the internet, I've got lots of actual first hand experience with various coatings helping to prevent corrosion.

So before you post a video trying to counter my experience and what most expert manufacturers say, get your facts straight.
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Wrong...
https://www.bladeforums.com/threads/dlc-coating-rust-corrosion-resistance-question.894294/
There are more posts from Sal himself.
There's alot of threads saying it's all bs. I'm not going to test it. I respect sal's personal experience.
 
Listen, it is relatively simple. Rust derives from ferrous metal oxidising due to exposure to H2O, whether in liquid form or as gaseous vapour in humid conditions. Or both. Any coating, be it crappy paint, DLC, whatever, will put up a minor barrier to rust taking hold. Much as Sal is a wonderful guy, if you are claiming that he says that coatings do not protect at all from oxidisation, then he is wrong. I suspect he didn’t say that, however, sir.
 
Seems to me that, living here in Oklahoma, I can have an M4 blade and keep it oiled and be fine. Were I living and working in salt water, then no. Still, giving up stainless seems like a high price. I'm glad I chose 20CV.
 
marrenmiller said:
I'd like to clarify something about my post above: I've had some M390/20CV/204p that was chippy (from ZT and Benchmade) and others that were just fine (Spyderco, Microtech, WE, Hinderer). Microtech's in particular has been very impressive. I just thought I'd share that sometimes, and from some companies, this alloy class might be inexplicably chippy, and it's really annoying when it is.
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that would make sense, whether or not it chips has a lot to do with heat treat and some of those manufacturers knives you had chip may have been a little too hard thus brittle and chippy.Your clarification makes your reply earlier sound much better. thx
 
almost all cardboard boxes have been treated for bugs , mold etc. That brown paper packing is also highly treated . Perhaps that treatment might include rust preventing chemicals .

But let me tell you about a new danger I experienced last night . I received a large box The box and all the packing paper was to go into my woodstove .The stove was lit and I grabbed the end of the paper I could see. I pulled and put the end into the stove . Now , the paper lit , I pulled to get the paper into the stove . And pulled .The paper kept coming, pulled more , the paper kept coming !! :eek: I pulled faster , afraid the whole strip of paper would ignite ! Like a Three Stooges film Finally the whole looonng paper was in the stove .The stove now hot had burned it all ! I let that burn down then cut up the box and threw that in. The box didn't chip my S-1 at all ! You just can't trust anything these days !:(
 
Mo2 said:
Wrong...
https://www.bladeforums.com/threads/dlc-coating-rust-corrosion-resistance-question.894294/
There are more posts from Sal himself.
There's alot of threads saying it's all bs. I'm not going to test it. I respect sal's personal experience.
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I respect Sal's experience and opinions....but that same experience and opinion causes him to manufacture some boneheaded knives(If you want to know what I think, start a thread on these idiotic monstrosities.). ALSO, many manufacturers coat and paint steel to keep it from rusting. So there's that.
 
Mo2 said:
Wrong...
https://www.bladeforums.com/threads/dlc-coating-rust-corrosion-resistance-question.894294/
There are more posts from Sal himself.
There's alot of threads saying it's all bs. I'm not going to test it. I respect sal's personal experience.
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Dude, look at what you actually said:
Mo2 said:
Coatings do not protect anything from corrosion.
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This is flat out wrong. I used spyderco as an example. In their catalog they say dlc helps with corrosion resistance. You are saying spyderco is lying to their customers. Fine, whatever.

Spyderco and dlc is just one example. Tons of respected companies claim rust resistance with all sorts of coatings, and I've experienced many of them. You are saying all coatings from all companies are bullshit. Think about that for a sec...

Please stop spreading blatant misinformation.
 
If you're really worried about your blade chipping, just get a knife with a 10xx carbon steel or 440A blade, or a SAK, or Opinel.
They don't chip, and will cut anything that is normally cut with a knife.
 
afishhunter said:
If you're really worried about your blade chipping, just get a knife with a 10xx carbon steel or 440A blade, or a SAK, or Opinel.
They don't chip, and will cut anything that is normally cut with a knife.
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And if I'm not really worried? Can I then get some opinions and discussion on 20CV?
 
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