I'm looking for an article on edge retention of skinning knives

gdpolk

gdpolk

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A while back I recall downloading a PDF copy of an article, that I think came from Blade magazine but I could be wrong on that detail, that tested various steels in the roll of skinning deer. There was 10-15 knife makers involved, all were given the same size/template/pattern of knife to make but allowed to choose their own steels, handle materials, and heat treat. The study was done double blind to the reviewer and knife makers (no logos on any blade and then shipped back to knife makers after the testing). The knives were tested by a deer processor and the pattern of the blade was his preferred size/shape of skinning knife. Each knife was sharpened by the deer processor and rated by the number of deer he could processes before resharpening. Then all were sent back to the maker for makers marks and the steel specifications were revealed.

If you know of where to find this article, please let me know as I'd like to revisit it for a while. Here is a photo of the results table if that jogs your memory, but I'd really like to actually read the whole article.
Thanks

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I'd like to read that article, too. I'm surprised that CTS 204P, which is chemically the same as Bohler M390, was so far down the list.

Tim
 
tim37a said:
I'd like to read that article, too. I'm surprised that CTS 204P, which is chemically the same as Bohler M390, was so far down the list.

Tim
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I wonder if it was a question of toughness playing in. M4 blew everything else out of the water and CPM154 matched up with S110V. I'm thinking if the blades were going through bone then the toughness of those two could have ended up as a more important factor than the wear resistance of S90V, 204P and S110V.
 
I think I did read this same article and if I remember correctly I think someone said they think heat treating was the major contributor to the performance outcomes of these test blades. And also if I remember correctly I think they said the CPM154 was heat treated to HRc 62 which helped it do as well as it did.
 
Scott Hanson said:
I think I did read this same article and if I remember correctly I think someone said they think heat treating was the major contributor to the performance outcomes of these test blades. And also if I remember correctly I think they said the CPM154 was heat treated to HRc 62 which helped it do as well as it did.
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Yes, that was a big part of it as I recall. The full article listed the harnesses of each blade too in another table and talked about some of the other factors that contributed to the scores as shown. I thought I had saved the article somewhere for future reading but I just can't seem to find it any more. If I recall correctly, BLADE just gave them a blue print essentially and told them to all make the same knife in whatever steel/handle/heat treat they wanted.

I remember thinking at the time though that the worst performance was 3-4 deer and for my needs that's all I need out of a weekend worth of hunting, so looking at other factors such as ease of sharpening, stain resistance, etc may make for a better overall real-world performer despite lower edge retention.
 
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lessismore said:
August 2014 issue of Blade magazine, page 36.
The link takes you to a 56 mb download.

http://www.google.com/url?sa=t&source=web&cd=4&ved=0ahUKEwis-vTnvvXKAhUE5GMKHSnnAcYQFgglMAM&url=http%3A%2F%2Fmedia2.fwpublications.com%2FBLA%2FBL_20140801e.pdf&usg=AFQjCNGHvezH-mV5Tc22ndo5hosS271WCA&sig2=7k1qOGiS5GyJPSzq0wAJ5w
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Yes that is the article I read, thanks for the link lesssismore, I used mainly CPM154 and S35VN now days in the knives I make, I was using S30V when it first came out but had since then switched to S35VN it's pretty much the same performance with out all of the other issues like more difficult to grind and sharpen.I have my blades heat treated with a cryogenic cycle and double tempered to HRc 60-61 for S35VN and 61-62 for the CPM154. Feed back from some of the guy that use them in the field can field dress and skin about 7 deer with one but it's pretty dull when they bring it back for a sharpening. A friend of mine who is an avid hunter and a taxidermist has a 4" drop point model in S35Vn that he says he can do about 10 deer with it before he has to touch it up on a steel. He has this knife on his side from the time deer season starts to the time he done with all his taxidermy stuff in the summer, he brings his knife to me to touch up for him each fall before deer season and it's never needed more than a very slight hone on a hard black Arkansas and a strop with green chrome rouge.
 
A good article. CPM 154 was heat treated to 61. Thanks for the article. Note the deer used for this test were Texas whitetail. And it didn't say whether the count held does and bucks. A Texas doe will weigh 50 lbs. a large one 60 lbs. and bucks about double that weight field dressed. (the manner they would be brought into this processing shop.) Our mule deer weight 225-250 lbs. live weight. So, near 200 lbs. field dressed. Thus, the number of animals skinned should be reduced as size increases. Still, once I have field dressed, skinned and quartered a Mule Deer buck. Then put the quarters on ice and cleaned my tools. I'm ready for a chair at camp and don't want to do another one. Probably at that point most guys would look at their knife and give it a touch up. So, this type of testing (until dull) is very useful information. Thanks, DM
 
Another observation: The author didn't say what was used to sharpen the knives at Kurby's Sausage House. But with them processing that many deer a year, they probably have a Norton 313 Tri-Hone and sharpen their blades to the 200 grit SiC (middle stone). Or take them to the finer Norton India. As this system is common in meat markets. I could be wrong, just my thoughts. DM
 
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In this article something of interest was stated by custom make Tony Baker on pg. 39, "Rumor has been that vanadium creates a 'pull out' of the carbides on the edge. This test has proved the opposite for CPM S90V and CPM 110V. Both of these knives had less damage to the edes than any of the other steels." This has been erroneously stated in other Forums. That the vanadium carbides will pull out / plow out during use or sharpening. Whereas Mr. Baker expresses evidence to the contrary. DM
 
I am appreciative of the time and effort it took to conduct this test. However, I am a little disappointed that Hardness levels were given within a range rather than with an exact amount. The issue I take here is that two different hardness levels of the same steel can perform differently. For example, you might see a difference in toughness or wear resistance with CPM-154 @ 59HRC vs. 61HRC. This test was supposed to show which steel has the greatest wear resistance. Fair enough, but wear resistance can fluctuate up or down based on HRC, so what we should be looking at is what steels, "at equal HRC" have the best edge retention. That would generate a more accurate and concise test of how steels compare to each other. Otherwise, the data is misleading.

So much of how a steel performs, comes down to the way it is heat treated. Much of this is reflected in whether or not the maker can successfully reach their targeted HRC. And some steels perform best at different HRC than others. If you are going to evaluate how different steels perform, you need to evaluate how they compare at the same HRC. Then, you can know the limitations of each steel based on a particular category, in this case, wear resistance.

All the best.
 
baks, this article and subsequent testing was brainstormed by Warren Osborne. So, I cannot comment toward that part of your concerns. However, some steels will take a higher hardness without chipping, others won't. Secondly, each steel's hardness is given some in a range, others in one number. The ASTM standards for a certified hardness tester is +/- 1. So, these numbers could be very close to one another. Plus, the stated test parameters were that the makers could do their own heat treating. Yes, heat treating does affect edge holding abilities. DM
 
David Martin said:
In this article something of interest was stated by custom make Tony Baker on pg. 39, "Rumor has been that vanadium creates a 'pull out' of the carbides on the edge. This test has proved the opposite for CPM S90V and CPM 110V. Both of these knives had less damage to the edes than any of the other steels." This has been erroneously stated in other Forums. That the vanadium carbides will pull out / plow out during use or sharpening. Whereas Mr. Baker expresses evidence to the contrary. DM
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With regards to the above and highlighted bold. Carbide tearout of steels from my understanding of reading R. Landes work in "Messerklingen und Stahl" happens at lower than optimum edge angles to a specific steel. IF these knives were sharpened at around 15degrees per side I doubt one would experience the carbide tearout as described by Landes. IF they are sharpened to around 4 degrees per side, then one could experience carbide tearout, but even then, one would need a microscope and etching solutions to be able to see what is actually tearing out.

Secondly. One could easily harden CPM-S90V and CPM 110V for greater edge stability. With that said. I wish we knew what heat treatment approach was used by the makers.

Still a good article nun the less and I enjoyed it.
 
marthinus said:
With regards to the above and highlighted bold. Carbide tearout of steels from my understanding of reading R. Landes work in "Messerklingen und Stahl" happens at lower than optimum edge angles to a specific steel. IF these knives were sharpened at around 15degrees per side I doubt one would experience the carbide tearout as described by Landes. IF they are sharpened to around 4 degrees per side, then one could experience carbide tearout, but even then, one would need a microscope and etching solutions to be able to see what is actually tearing out.

Secondly. One could easily harden CPM-S90V and CPM 110V for greater edge stability. With that said. I wish we knew what heat treatment approach was used by the makers.

Still a good article nun the less and I enjoyed it.
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The whole subject of carbide tear out has been so overblown that it's gotten to the point of ridiculous.

Most of it has been used as a tool to fuel certain agendas and attract certain types of people to lean a certain way for various reasons.

In a nutshell it's all complete utter BS and irrelevant when it comes to knife blades as nobody would even be able to tell what was happening one way or the other unless they had access to an electron microscope. That is the problem that I have always had with this BS, the whole picture is never stated and used to fuel agendas, however the information is out there for those who actually care. That's the whole picture without certain things edited out.

In the end it doesn't freaking matter one way or the other because almost nobody has the equipment to measure it in the 1st place, some of us do and I can tell you it just doesn't matter either way. We are talking about knife blades here, not sending people to Mars.

People just need to focus on sharpening and getting a clean apex, the rest is really irrelevant.

Get the knife sharp, use it and enjoy it, sharpen it again once it gets dull and repeat. :)
 
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baksilum said:
...However, I am a little disappointed that Hardness levels were given within a range rather than with an exact amount...
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Sometimes the hardness is measured at more than one place, thus the range reflects the different values. There is no "one exact" measurement. In addition, every measurement has an uncertainty associated with it such as 60 +/-2, this is sometimes stated as 58-62.
 
As Ankerson says results in practice mean more than theorizing and conjecture. Hardness ranges are given because there is variations in the testers and the standards that they are calibrated against.

So a range is given to cover the actual results of the heat treat and the variation in testing equipment.

Also as the testing done here shows, geometry, as well as carbide content and heat treat are the three factors for edge retention. Higher carbide, harder heat treat and thinner grind all make edge retention better in abrasive applications like skinning.
 
^ Well said. Still, there has been a lot of hungry folks fed with meat processed by knives with lower carbide levels, lower hardness levels and a good thin grind. Just saying the best is not always used. But it still tastes good. DM
 
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