CPM-20CV Feedback vs m390

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microtech85

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Dec 1, 2015
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Hello, I have been carrying my benchmade 940-1 with cpm-20cv steel for close to a month now and I am very impressed with this steel. I have been carrying both this knife and my benchmade valet in m390 together for a few weeks. I have done the same cutting with both knives in edc use. They both started with hair popping edges. The 20cv has held a noticeably better edge after a little over 3 weeks of edc carry. I have touched up the m390 about once a week on the strop. I have not had to touch up the 20cv yet. My cutting involved: opening envelopes, cutting tape, a couple cuts through cardboard, opening plastic packaging, cutting cheese, cutting apples, sharpening one pencil each, cutting paper towels and phone book paper as sharpness tests, whittling a stick, cutting gauze and medical tape, grooming finger nails, cutting electrical tape and stripping insulation off of 3 14awg wires with each knife.
Furthermore, the 20cv seems to be a more aggressive cutter. Its cutting ability reminds me of s90v. But it takes a very keen edge like m390. To me the 20cv seems like the best of both worlds. It is as though s90v and m390 had a baby together and named it 20cv.
It has only been three weeks but i am liking this 20cv very much. It takes an impressive edge but even more impressive is how keen the edge has remained after 3 weeks of edc use. The 20cv is sharper after three weeks than my m390 was after only one week. In the end, the 20cv is still popping arm hairs after three weeks with no touch-ups, where the m390 has required about a weekly stropping to maintain that ability.
 
The only difference between the two steels is the silicon content (CPM-20CV: 0.03%; M-390: 0.07%), and that they are produced by different steel makers. Could be the heat treat and/or blade geometry makes the difference. I am highly impressed with CPM-20CV (Spyderco Mule), too.
 
microtech85 said:
Hello, I have been carrying my benchmade 940-1 with cpm-20cv steel for close to a month now and I am very impressed with this steel. I have been carrying both this knife and my benchmade valet in m390 together for a few weeks. I have done the same cutting with both knives in edc use. They both started with hair popping edges. The 20cv has held a noticeably better edge after a little over 3 weeks of edc carry. I have touched up the m390 about once a week on the strop. I have not had to touch up the 20cv yet. My cutting involved: opening envelopes, cutting tape, a couple cuts through cardboard, opening plastic packaging, cutting cheese, cutting apples, sharpening one pencil each, cutting paper towels and phone book paper as sharpness tests, whittling a stick, cutting gauze and medical tape, grooming finger nails, cutting electrical tape and stripping insulation off of 3 14awg wires with each knife.
Furthermore, the 20cv seems to be a more aggressive cutter. Its cutting ability reminds me of s90v. But it takes a very keen edge like m390. To me the 20cv seems like the best of both worlds. It is as though s90v and m390 had a baby together and named it 20cv.
It has only been three weeks but i am liking this 20cv very much. It takes an impressive edge but even more impressive is how keen the edge has remained after 3 weeks of edc use. The 20cv is sharper after three weeks than my m390 was after only one week. In the end, the 20cv is still popping arm hairs after three weeks with no touch-ups, where the m390 has required about a weekly stropping to maintain that ability.
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This is similar to results I've had with M390 and 20CV as heat treated by Benchmade. Which is interesting as they list their M390 RC at 60-62 and their 20CV RC at 59-61.
 
Halden...that is quite a significant difference in hardness...one would suspect that the M390 would hold the edge much longer...but then, I'm usually wrong about these things.... :)
 
Sonnydaze said:
Halden...that is quite a significant difference in hardness...one would suspect that the M390 would hold the edge much longer...but then, I'm usually wrong about these things.... :)
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It could also just depend on the particular knives. Say the OPs Valet happened to be hardened at the low end of the scale at 60 and the 940 on the high end at 61. That could do it.

Or the geometry could be playing a role, or more likely a combination of both.
 
the differences you are experiencing are more likely due to geometry, edge sharpness, or heat treat

For cutting purposes, 20CV and M390 are likely indistinguishable. I think M390 is a little easier to finish than 20CV but I could be mistaken or biased. M390 is probably slightly tougher due to the 3rd gen PM tech but again I don't have personal evidence of this. But either way 20CV and M390 are plenty tough for small to midsized blades. I wouldn't use either for a really big chopper but all things considered they have solid impact strength.
 
Huntsman Knife Co. said:
the differences you are experiencing are more likely due to geometry, edge sharpness, or heat treat

For cutting purposes, 20CV and M390 are likely indistinguishable. I think M390 is a little easier to finish than 20CV but I could be mistaken or biased. M390 is probably slightly tougher due to the 3rd gen PM tech but again I don't have personal evidence of this. But either way 20CV and M390 are plenty tough for small to mid sized blades. I wouldn't use either for a really big chopper but all things considered they have solid impact strength.
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i too had thought benchmade heat treated their m390 to 60-62. But i checked on their site under the steel info section; they are now treating it 58-61, and doing 20cv 59-61. It is interesting to me because they are both good steels on good knives and heat treated to a similar hardness by the same company. There may be many reasons that my 20cv has out performed my m390 in edge stability or edge retention. But the main point of my post is to say that i am liking 20cv better regardless of what the technical reason may be. I went in expecting to like m390 better because we have all heard the "3rd generation" processing and such things. And I know edge geometry will make a difference when cutting through an apple or cardboard, but will it really make a difference shaving arm hair if both edges are sharpened to the same angle? Remember, both started out hair popping sharp. But after initial sharpening, i was able to whittle a hair easier with my valet than i could with the 940. I am thinking that 20cv has similar properties to m390 but has a more aggressive cutting nature like s90v. I imagine m390 may be the tougher of the two from what we have heard about the "3rd gen" but i have not experienced any such thing first hand. Benchmade says that m390 is tougher but that 20cv has better edge retention.
 
microtech85 said:
i too had thought benchmade heat treated their m390 to 60-62. But i checked on their site under the steel info section; they are now treating it 58-61, and doing 20cv 59-61. It is interesting to me because they are both good steels on good knives and heat treated to a similar hardness by the same company. There may be many reasons that my 20cv has out performed my m390 in edge stability or edge retention. But the main point of my post is to say that i am liking 20cv better regardless of what the technical reason may be. I went in expecting to like m390 better because we have all heard the "3rd generation" processing and such things. And I know edge geometry will make a difference when cutting through an apple or cardboard, but will it really make a difference shaving arm hair if both edges are sharpened to the same angle? Remember, both started out hair popping sharp. But after initial sharpening, i was able to whittle a hair easier with my valet than i could with the 940. I am thinking that 20cv has similar properties to m390 but has a more aggressive cutting nature like s90v. I imagine m390 may be the tougher of the two from what we have heard about the "3rd gen" but i have not experienced any such thing first hand. Benchmade says that m390 is tougher but that 20cv has better edge retention.
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An important thing to note is that 58-61 and 59-61 is a massive variable. With many super steels, even half a point of hardness can result in a measurable difference in performance. 2 points could be night and day.

With that said, the more aggressive cutting you are experiencing could possibly be due to the grain structure, the coarser the grain, the more aggressive the cut, generally speaking.

Maybe someone with more experience with the two can chime in. I've done very extensive testing with m390 and far less testing with 20CV but in my experience, for a small to medium sized blade they are interchangeable.
 
I have an m390 blade from Benchmade that I tested at about 57 Rockwell. It completely changes how the steel acts—more like an aggressive s30v for cutting and VG-10 like sharpening, not too bad in my opinion.

I’d love to get more m390 and 20cv or 204p so I could really form an educated opinion on the matter.
 
My benchmade 940-1501 CPM 20v blade is my favorite blade steel in my knife fleet. I don’t know why, just know it’s awesome after carrying and using the knife. I also have many, many Elmax blades, S30/35/90 blades and a couple Microtech M390 blades all are great steels overall.

I would like to buy more blades in the CPM 20v steel so I can get a better feel if I just got a really good blade or if there’s more too it than that. I also have the 940-1 CPM 90v a great blade also, but I prefer the 940-1501 20v’s blade. My two M390 Microtech LUDT’s are very impressive also. I’m finding the CPM-20 and M390 steels to maybe be the perfect steels for me. I love Elmax also, but it’s a touch less edge holding ability from my personal field use.
 
The steel composition is nearly the same, the process to make the bar stock is slightly different but basically the same. Heat treatment may be different from factory to factory. Benchmade often have higher hrc on premium models than spyderco. But hrc doesn't tell you everything. You can have two blades exactly alike and heat treated differently and get the same hrc and performance can be very different. Not to mention each batch of heat treated blades can vary.
 
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I like both m390 and 20cv. But 20cv seems to be something special. Maybe i just got a great specimen with the 20cv and an average specimen with the m390. Who knows. But what i do know is that i have not had a steel hold such a fine edge for this long before.(1) I liked the s90v that came on my 940-1 for its aggressive cutting nature but it was so difficult to get it to that supreme level of sharpness that i am able to get m390 and 20cv. Plus, even though the s90v would hold an acceptable edge for a very long time, it wouldn't hold a super keen edge for very long. I like to maintain keen edges on my knives, so i value knives that have good edge stability and wear resistance. It seems 20cv has both of these traits. Other steels may have more wear resistance, but lack in edge stability. All in all, i think the 20cv and m390 class of steels are an ideal edc steel.

(1). I own or have recently owned these steels: s90v, s30v, s35vn, m390, 20cv, vg10, 14c28n, 420hc, 1095, 12c26. My cpm steels have been from spyderco, benchmade and zt.​
 
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Looks like I will want to pick up a 20cv at some point to see how it fairs. I have multiple M390 blades - BM Contego, several CKF's - and currently just one 204p - Spydie Military (have had a couple Southards that I've passed on). The 204p Military has been absolutely amazing so far - no need to retouch the edge at all.
 
m390 seemed strong yet "somewhat flexible" in contract to 20cv... My Socom elite tip broke with very light lateral force on it.. I remember my 390 handling quite a few more tasks and that was on a para 2, much less spine/blade thickness.
 
I have had this experience as well, and with other makers. They are too similar in composition to be because of alloying differences, I would think. My theory, is that the more refined steel, the 3rd Gen PM, with the smaller carbide size and microstructure, is less toothy and loses its sharpness quicker, especially with abrasive materials. I find 20CV my favorite of the family(20CV, M390, 204p) because it is toothy, yet is can get screaming sharp. It has larger carbides which would give it the advantage in edge holding, especially with abrasive materials.
That is just my humble opinion. Just a possibility

On the other hand. With D2 and CPM D2, (by the way, LOVE my Protech knives in CPM D2, amazing!!!) Anyways, I find that the CPM D2 holds a high sharpness edge longer than my D2 knives, but the D2(with the very large carbides) holds a working edge for a very long time. Different than my experience with 20CV and M390/204p. Interesting.
 
ATJ999 said:
I have had this experience as well, and with other makers. They are too similar in composition to be because of alloying differences, I would think. My theory, is that the more refined steel, the 3rd Gen PM, with the smaller carbide size and microstructure, is less toothy and loses its sharpness quicker, especially with abrasive materials. I find 20CV my favorite of the family(20CV, M390, 204p) because it is toothy, yet is can get screaming sharp. It has larger carbides which would give it the advantage in edge holding, especially with abrasive materials.
That is just my humble opinion. Just a possibility

On the other hand. With D2 and CPM D2, (by the way, LOVE my Protech knives in CPM D2, amazing!!!) Anyways, I find that the CPM D2 holds a high sharpness edge longer than my D2 knives, but the D2(with the very large carbides) holds a working edge for a very long time. Different than my experience with 20CV and M390/204p. Interesting.
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ive thought the same thing about 20cv possibly having a coarser grain. I think it is a nice quality for cutting performance as long as the steel has a requisite toughness for edge stability and durability. I was reading a pdf from bohler and it was saying that the 3rd gen has to do with having fewer non-metallic inclusions or impurities. So as their manufacturing has advanced, their steels have become tougher as a result of fewer inclusions; a "cleaner" steel. Whatever goes on at the microscopic level, i do not know, but i have always been satisfied with the way benchmade heat treats their steels. Benchmade used to list their m390 at 60-62hrc but now at 58-61. I wonder why they did that.
 
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