Let down by 20CV

[OrangeBlueOrangeBlue]

I don't think it's an issue of burnt edges. M390/20Cv are not tough steels by any measurement. Top that off with thin edges with the angles you have along with the key here. Plastic banding is hell on edges. If you have any side loads on that edge while cutting at all you have a perfect storm for chipping. Try it at a lot thicker/higher angle if you intend to cut that plastic edge breaking stuff again and do it very carefully. Look at the complaints like yours that stuff has caused over the last 10 years.

Every steel/heat treat/edge knife blade has a limit for every job. That job exceeded the limit for a high carbide steel at high hardness at those geometry s. Either thicken it up or do what many of us do and use a throw away blade on those wretched things.



Joe

I think the method of sticking the blade under the strap, rotating it into position, and then pulling against the tension of the strap is probably not the most edge-friendly way to do it. Much less likely to torque the blade if you slide a scrap of cardboard underneath the strap and just cut normally.

 

[Malty Falcon]

I have a BM Vector 496 with 20CV STEEL. It has a compound grind, and I was unimpressed with the chipping/deep scratching on the forward portion of the blade. I sent it back to benchmade for inspection.

Their response was to test it's hardness and re-grind the edge. They reported that it came out to 60 Hardness, which is within specs.
I won't pretend to be able to determine if it was a "burnt" edge, but the re-grind they did is much better. The edge lasts longer on the forward portion, and the scratching from hard use is greatly diminished. At least Benchmade fixed it for me.

I am very interested in supersteels, and expect them to perform much better than inexpensive steels. I wouldn't be very happy with the OP's chipped blade, or having to sharpen a knife 5 times before it performs like a superstar. Do manufacturers want us to believe they ruin a blade with the factory sharpening, and that knives require the end user to "finish" the edge for them?

 

[soc_monki]

I think the method of sticking the blade under the strap, rotating it into position, and then pulling against the tension of the strap is probably not the most edge-friendly way to do it. Much less likely to torque the blade if you slide a scrap of cardboard underneath the strap and just cut normally.

Or you can use a pair of diagonal Cutters. I use them every day to cut banding, straps, wire, cable ties... Theyre made for that use. Knives don't work half as well.

Just a thought.

I have plenty of 20cv and M390, and have never once had one chip, roll, or get damaged. Dull? Yes. Maybe I'm not hard enough on my knives?

 

[Alberta Ed]

I wouldn't blame the steel; CPM 20CV is pretty good stuff but any steel at a very acute angle cutting hard stuff can chip. CPM S110V would probably stand up better, or some of the tough tool steels like 8670, 1095 Cro Van, S7, etc.

 

[Danny Linguini]

"A friend of my cousin's neighbor had this knife.; and blade was so badly chipped..."

I think I know that guy!

 

[DMG]

I think I know that guy!

He posted on here with a Contego that looked like he tried to serrate it himself!

 

[jstn]

20CV seems like an odd choice for a “hard use” knife like Hinderer. My Xm in s35vn is great, but seems Cruwear or Magnacut would be more appropriate.

 

[LostCause]

I purchased a new knife in 20CV earlier this year, and let's just say it was from a very reputable US manufacturer. I immediately chipped the blade in a couple locations. One was my fault hitting a staple behind some tape. With that said both times the pressure was very light and in line with the blade. I stropped it a few times thinking it was a feathered burr but the chips remained. I picked up a Work Sharp precision adjust, and worked out the chips to a 17 degree angle. The original grind was between 16 and 17 so I figured the steeper of the two would be better. The edge came out great and I finished with the strop. Fast forward to today after cutting plastic pallet banding, and this thing looks like an old hockey player. It has multiple chips and rolls after cutting maybe ten bands. Is this the trade off for edge retention? This has been by far the most delicate steel on the verge of egg shells I have ever used. I am going to profile it again to 20 degrees to see if there is a change. What am I missing?

Impossible! Expert bushcrafters have told me that my CPM-3V fixed blade is garbage because it's not stainless and that M390 and ELMAX run circles around it with all that edge retention and stain resistance while being tough enough. And if I hit a grain of sand then I'm inexperienced and I don't know what I'm doing...


Sarcasm aside, I'm sorry this happened to you bro. I never experienced similar issue even with 1095 or 5160 and basic steels. I guess it's either faulty HT or it's just too much to expect these hard steels to be able to withstand impacting hard objects like a staple.

I'd try contacting seller or manufacturer.

 

[Another Shepherd]

I buy a lot of (in other words, too many) Benchmade knives because multiple local dealers have them. So I also read a lot of reviews of Benchmade knives. I have seen far more complaints about 20CV chipping than any other steel. I have also examined a lot of Benchmade knives on dealers' shelves, and the only such knife that I have seen with a damaged edge was an Anthem with 20CV. I trust the dealer in saying he was unaware of seeing the Anthem with any use other than slicing paper (that was me). I have no conclusive evidence that Benchmade 20CV is worse than any other steel, but it seems prudent to me to avoid 20CV. I have several Benchmade knives with M390 and one with S90V. I have cut zip ties and blister packs with these knives and had no edge problems.

I also have some M390 knives from other manufacturers and I have been very happy with them.

I think I have no 20CV knives, but I'm not sure.

 

[Skywalker31]

I've had a couple knives with 20CV/M390/204P that had unimpressive factory edges before a few sharpenings or before a reprofile, but once I re-did the edges I've ended up very satisfied with all of them.

Benchmade 710DLC-1 in M390 was not all that great for edge retention before a reprofile on the edge pro; Spyderco Manix2 LW in 20CV picked up some nice chips from a copper staple but hasn't had any issues since after a little work on the CBN benchstone, just matching the factory bevel.

Here's the 20CV Manix's original chips, for e.g. -

M390/204P/20CV is still my preference for high wear resistance stainless in folders that I know will be used mostly for slicing - to this day nothing has kicked that M390 710 out of my pocket as a hunting knife, for field dressing and skinning. And I've really been liking the CollectorKnives Italian slipjoints in M390; it's a perfect steel for that application. But I am aware that the factory edges in this steel might take a little work, and if I think I might be a little rougher or be making twisting, edge-torquing cuts I grab a folder in M4 or K390 or a fixed blade instead.

I'll also echo comments about it being a weird choice for thicker blades more aimed at durability/toughness, esp the 4mm+ thick ones.

 

[LostCause]

I'll also echo comments about it being a weird choice for thicker blades more aimed at durability/toughness, esp the 4mm+ thick ones.

Things get moot from time to time as people like to push other people into buying same stuff thay they have. My upper comment about bushcrafters telling me 3V is bad is unfortunately what really happened to me.

"Elmax is tough enough not to break unless you abuse it, holds better edge by long shot and is stainless"
- 3V also won't rust unless neglected. And what if I hit grain of sand or pebble or a rock?
*guy mumbles how I don't know what I'm doing and other crap*

As much as thin wear resistant slicers are amazing thing to have, sometimes it's worth it to lay them aside and just brute through with thicker beefier blade or use some tougher carbon steel even if it doesn't have high edge retention.

I've cut copper wires with good old 1095 and had no edge damage, and high end steel such as 20CV or M390 suffering that kind of damage from a zip tie is just unacceptable in my book.

 

[Chronovore]

So is this thread one of those where you could literally replace the 20CV in OPs title/post with, say, S35VN or other mainstream steel and get the exact same 2 pages of responses?

This is true to some extent. While S35VN isn't usually chippy, factory blades will often come with a noticeable degree of edge fatigue. The heat treatment, especially on bargain-priced blades coming out of China, will rarely be ideal. I mentioned Outpost 76 earlier and his testing on production knives in S35VN has led to similar conclusions.

This kind of thing was a big issue for Chinese D2 a year or two ago. In cut testing from multiple sources, using different methods, it just never seems to get near the reputation that was built by more expensive American knives. Some of that could be issues in mass-production heat treatment. Some of that could be the source or purity for the D2 in question. (There had been issues with vanadium levels in XRF testing.) Whatever the case, the actual edge retention just wasn't great. Sure, the performance was significantly better than 8Cr13Mov and honestly okay for knives in the $30-50 range, but nowhere near what it should have been.

On the other side, there are cases where production knives get a good heat treatment. Buck's 420HC is a great example. Another one is WE's 9Cr18Mov. They've really nailed the mass-production heat treatment for that steel. As a result, the Civivi and Sencut knives in 9Cr18Mov will generally out-cut Spyderco's VG-10 and achieve performance closer to budget renditions of super steels. While S35VN might be tougher and 20CV might be more stainless, the irony is that WE's premium knives in those steels don't have much to offer in edge retention versus their budget knives in 9Cr18Mov.

 

[jjg6319]

I understand, but I didn't want to throw a company under the bus for what may be no fault of their own. I will say the initial sharpening had to be touched up as soon as I got it for a very pronounced burr on the belly of the blade. I am not saying I will not name the manufacturer, but for now I am testing the waters. From what I have seen so far I will be profiling this blade once a quarter with what I would call normal use.

I bet on Hinderer too.

 

[scubadoober]

It wasn’t zip ties for reference, this is what I was cutting that did the damage. Not the metal the poly banding. Probably ten total. I have a flex steel carving knife in 1095 and it is indestructible compared to 20CV.

 

[marrenmiller]

Others have gotten on this already and it's a real issue. If you don't follow Outpost 76 on YouTube, check him out. He has shown it empirically with lots of different steels from lots of different companies from different countries. The depth of the fatigue can vary too. Sometimes, edge retention values stabilize after just a few fresh edges. Occasionally, they can continue to improve past where he is willing to go.

There can be other issues besides the fatigue from the factory grinder. Outpost 76 is planning a video overview on this family of steels and I'm looking forward to it. Apparently, a good production heat treatment is hard to find for these steels. Much like Chinese D2 in budget knives, it seems that production M390 and 20CV can be decent for various EDC needs but will often fall short of expectation based on things like Larrin's ratings.

Love Outpost76's videos. His video on the Benchmade Super Freek taking a dozen edges to hit good steel should be mandatory viewing for enthusiasts.

 

[POCEH KOCEB]

I used to cut lots of those straps while unpacking pallets. My Manix 2 in s30v never had issues with it but I had other knives that would micro chip factory edge if I move sideways while I’m cutting the strap. This is very hard material, I found out it easier to cut it in angle instead going 90degrees to the strap.

 

[golddots]

This is what is great about having so much variety. If a steel or edge angle or whatever doesn’t work out I try something else or combination of something different.
I’d just move away from the 20cv.
Ever since I started using cruwear and k390 I no longer have chipped or rolled edges. I never measured how much I cut but I recall sharpening out many chips in s30v/m390/20cv etc.
maybe Magnacut will work for the OP if toughness and stainless is needed.

 

[marrenmiller]

...
Ever since I started using cruwear and k390 I no longer have chipped or rolled edges. I never measured how much I cut but I recall sharpening out many chips in s30v/m390/20cv etc.
maybe Magnacut will work for the OP if toughness and stainless is needed.

I concur. I made the switch to mostly tool steels and at this point I don't really remember what it feels like to sharpen out chips and fix rolled edges.

 

[Chronovore]

This is what is great about having so much variety. If a steel or edge angle or whatever doesn’t work out I try something else or combination of something different.
I’d just move away from the 20cv.
Ever since I started using cruwear and k390 I no longer have chipped or rolled edges. I never measured how much I cut but I recall sharpening out many chips in s30v/m390/20cv etc.
maybe Magnacut will work for the OP if toughness and stainless is needed.

I'm still a fan of good ol' 14C28N. It's one of the toughest stainless steels. It has very good corrosion resistance. The edge retention might not be notable versus modern super steels, but it's not bad. It's a solid step up from stuff like 8Cr13Mov and on the budget knives where we usually see it, the edge retention is pretty good.

 

[greater]

"Super Steels" that perform no better than average regular steels. The knife industries dirty little secrete Quality control sacrificed to meet the needs of mass production and replaced with marketing of said "Super Steel" with nary the mention of improper low cost manufacturing techniques making for an overall bad value. It's all deja vu to me and unfortunate.

It may be a better bet to get a steel that one has to really try hard to get the heat treat and whatever else wrong ???