Cpm 20cv question

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Vlade

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Feb 8, 2020
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Good morning gentleman, I'm looking at purchasing a new knife the blade steel is CPM 20cv. It's a zero tolerance. I'm not the best at sharpening. I use a whetstone a ceramic sticks and a strop. I can sharpen 420hc, Aus 8A, Aus 10A, carbon steel, but I've heard horror stories about sharpening 20 CV. I don't have any to compare with so I was hoping that somebody here could tell me how hard is it? I don't want to drop cash on a knife that I cannot sharpen. I was hoping somebody could guide me on a correct sharpening system for this type of Steel. Thank you in advance for your considerations
 
what grit is your whetstone? imo, its mostly a non-issue, im sure you will be fine if your technique is sound.
 
I like diamonds for harder steels like 20CV. Touch ups on ceramic rods are fine, but if you really need a good sharpening or want to reprofile, it's hard to beat diamonds. If you adept at freehand sharpening with a whetstone, something like a DMT benchstone might be a good option without having to buy a whole new system.
 
sadmin said:
what grit is your whetstone? imo, its mostly a non-issue, im sure you will be fine if your technique is sound.
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I've had it for years and I don't recall but it's probably somewhere around 1,000 grits per square inch. When I get done with that I stroke it on ceramic. And then finally strop them. They could shave hair when I'm done with them. So in your opinion you're saying go ahead and get the ZT? It's one of them knives I just have to have I guess. Thanks PS what about a belt sander? I've been meaning to get one of them for a long time anyway.
 
I use a Work Sharp guided, and a strop. Both have worked very well on my 20CV Bugout. Zero difficulty. Hope this helps.
 
Vlade said:
I've had it for years and I don't recall but it's probably somewhere around 1,000 grits per square inch. When I get done with that I stroke it on ceramic. And then finally strop them. They could shave hair when I'm done with them. So in your opinion you're saying go ahead and get the ZT? It's one of them knives I just have to have I guess. Thanks PS what about a belt sander? I've been meaning to get one of them for a long time anyway.
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Never use a belt sander -- that can ruin a blade in an instant. If what you have works for you, no need to change. Diamond hones work well on powder steels with high carbide content like 20CV.
 
i use a sharpmaker with the boron nitride rods on 20cv, s90v, etc, without issue. have done 20cv with just the medium & fine rods but it takes longer
 
Best option is to get a strop and use some Diamond or CBN on the strop. I picked up some 16 micron CBN and it worked really well to bring back some 62 rockwell Elmax and some CPM 20CV and was easy to touch up with a 3 micron diamond paste on the other side of the strop after that. If you keep it sharp, it will be less often you need to take it to the stones to restore the edge completely. Lots of guys go to 1 micron or less on strops, but I like a coarser compound in general. Had some 8 micron and 2 micron CBN on another strop that worked well, but took longer. The 16 micron worked quick and the edge off the 3 micron afterwards was shaving sharp and still had some bite left to it.
 
Taz said:
Best option is to get a strop and use some Diamond or CBN on the strop. I picked up some 16 micron CBN and it worked really well to bring back some 62 rockwell Elmax and some CPM 20CV and was easy to touch up with a 3 micron diamond paste on the other side of the strop after that. If you keep it sharp, it will be less often you need to take it to the stones to restore the edge completely. Lots of guys go to 1 micron or less on strops, but I like a coarser compound in general. Had some 8 micron and 2 micron CBN on another strop that worked well, but took longer. The 16 micron worked quick and the edge off the 3 micron afterwards was shaving sharp and still had some bite left to it.
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Yeah I was kind of thinking that keeping it sharp is the most important thing. Not letting it get dull to begin with. Thanks again
 
Waterstones like Shapton Glass Stones or Pro Stones work well. I use a Bester 1200 and Rika 5K and then strops on Elmax, CPM20CV/M390 and other steels and they work pretty well as long as I don't need to do major chip repair. Arkansas stones and other whet stones may not work as well. Cheapy stones from other vendors also may not work as well.
 
I carry 20cv Watu most of the time and aside from putting an alternate edge angle on it when I bought it, only use ceramics to keep it sharp.
This steel is quite easy to maintain sharpness with weekly (sometimes daily) two minute sessions on the Spyderco Sharpmaker med/fine rods.
The ease of maintenance that I experience may come down to blade and edge geometry though, I am not sure.
Definitely faster to reprofile or repair chipping with diamonds but not needed otherwise.
 
I don't know guys I'm not really too good at sharpening. But ZT does have sharpening service. But it would probably take a Month of Sundays to get it sharpened because they're in Oregon. Is there anyone here on blade forums that sharpens knives?
 
Where are you located? There may be someone near you that can help you out or show you how to sharpen!
 
Vlade said:
I don't know guys I'm not really too good at sharpening. But ZT does have sharpening service. But it would probably take a Month of Sundays to get it sharpened because they're in Oregon. Is there anyone here on blade forums that sharpens knives?
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The edge ZT puts on it won't be any good, so don't bother with that. If you send it to anyone, make sure they don't use a belt grinder to sharpen it.

Really, the best option is just to sharpie the edge and spend an hour figuring it out. You'll be happy you did.
 
I use DMT stones(duo fold and bench) for almost all of my sharpening(20CV, 3V, S35VN, S30V, D2 and a variety of simple carbon steels) and have never had any issues. I do have some ceramics(Spyderco Tri-Angle Sharpmaker and the benchstones) but don’t use them as much.
 
My suggestion: either send it to a reputable sharpener or get yourself something like a Worksharp Precision Adjust (fixed angle sharpener). The WS is about $60 and it comes with two diamond grits and a ceramic finishing stone.

Yes, you can sharpen 20cv on non-diamond/CBN stones, but it takes a long time and you won't get the full performance of the steel.
 
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