Steel Chart draft 1

Cpm154 is tougher than L6 and 5160? Really? I am not challenging you but the info. I would love to see real proof of this. Also, s7 should be on that list as number 1 in toughness.
 
Cobalt said:
Cpm154 is tougher than L6 and 5160? Really? I am not challenging you but the info. I would love to see real proof of this. Also, s7 should be on that list as number 1 in toughness.
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good catch, changed. Here is niagara's chart. It was very helpful. Honestly CPM 154 surprised me with how high its toughness was rated. I see why a lot of makers like to use it, it pretty much does everything reasonably well.

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Just to muddy the waters -- CPM will improve toughness but mostly transverse toughness . In steels with large carbides the fracture will go from carbide to carbide . With small carbides like CPM fractures will only sometimes go from carbide to carbide but will normally go in between carbides .
 
True, but you can get the same results with a great HT. There is much hype to cpm. The steels are good but not as good as claimed over other steels.
 
Cobalt said:
True, but you can get the same results with a great HT. There is much hype to cpm. The steels are good but not as good as claimed over other steels.
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In a case where high toughness is not required the benifit to CPM 154 versus 154-CM would be pretty small. The point of these charts is to be able to make those kinds of observations when people are picking a knife. Ironically many folks mix up 154-cm with CPM 154 anyway.

Another thing that these charts illustrate is that you have to give something up to get something, if you want top edge retention you are going to have to pay with either low corrosion resistance or lower toughness.
 
I question the validity of cpm's claims. Which is really all there is. I have called cpm and asked for specific information on their chirpy testing. They could not provide any specifics of who conducted the tests, when, using what equipment is all a mystery. I specifically asked them. All I got was crickets. I waiting for someone to come out with independently verifiable tests of many of these steels.
 
Cobalt said:
I question the validity of cpm's claims. Which is really all there is. I have called cpm and asked for specific information on their chirpy testing. They could not provide any specifics of who conducted the tests, when, using what equipment is all a mystery. I specifically asked them. All I got was crickets. I waiting for someone to come out with independently verifiable tests of many of these steels.
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Unfortunately alot if data we have is from manufacturers (biaised and unverified)
Very few people have the time ir capacity to really compare steel toughness, edge holding etc...

The chart that the OP is making is not really that useful since it us based on unverified data or 'expert opinion'
 
True, but I see nothing wrong with a knife maker trying to help buyers out by giving them a little knowledge as creely is trying to do. It is a good intro to knife steels.
 
Personally I think you should avoid specifics. Have different classes of steels, plain carbon, tool, and stainless, and then subdivide that into different categories for different uses, and then have on the side some examples of each class and subclass that you personally use and manufacturer's data linked to the ones you haven't used along with links to some valid testing done of other steels that go into why heat treatment and geometry are so important and why one knife would be great for one purpose and terrible for another.

That would go a long, long ways toward giving a proper education to your customers without getting bogged down with ranking specific steels.
 
I get what you are trying to do and it would be nice if standardized quantifiable data were available. The problem is that with such a wide range of steels and claims about them, many will just take charts like this at face value. There are very knowledgeable folks here and many with a high level of sophistication in the evaluations of the merits of different steels for different attributes and purposes. Just seeing how unstable your rankings are does not inspire confidence that this will, in the end, be useful or informative. You are probably better off advising customers about pairwise comparisons for specific attributes rather than presenting a sweeping claim, however well-intended or however thoughtful YOU are. Many people will simply look at the chart and that will be the beginning and end of their critical thinking. My 0.02.
 
dogrunner said:
I get what you are trying to do and it would be nice if standardized quantifiable data were available. The problem is that with such a wide range of steels and claims about them, many will just take charts like this at face value. There are very knowledgeable folks here and many with a high level of sophistication in the evaluations of the merits of different steels for different attributes and purposes. Just seeing how unstable your rankings are does not inspire confidence that this will, in the end, be useful or informative. You are probably better off advising customers about pairwise comparisons for specific attributes rather than presenting a sweeping claim, however well-intended or however thoughtful YOU are. Many people will simply look at the chart and that will be the beginning and end of their critical thinking. My 0.02.
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The area I am least versed and the most unstable rankings are in toughness, primarily because that is not a top attribute I seek with the knives I use or make. To that end I have had very little pushback or change on the edge retention list or the corrosion list, areas I have always been more interested in and better versed. The toughness list has moved around a lot from where it started (looking back it was embarrassing), but that is why I came here because there is a deep well of knowledge. In fact on one of the groups I posted this to I got a lot of good toughness info from a significant knife manufacture owner. I am becoming more confident that the toughness list is shaping up into a reasonable guide.

I have faced a fair amount of scrutiny and lessons in humility for these lists, but I have calculated the the hassle to be worth a good final product.
 
bodog said:
Personally I think you should avoid specifics. Have different classes of steels, plain carbon, tool, and stainless, and then subdivide that into different categories for different uses, and then have on the side some examples of each class and subclass that you personally use and manufacturer's data linked to the ones you haven't used along with links to some valid testing done of other steels that go into why heat treatment and geometry are so important and why one knife would be great for one purpose and terrible for another.

That would go a long, long ways toward giving a proper education to your customers without getting bogged down with ranking specific steels.
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With rankings you certainly run the risk of stirring up opinions, but at this point the the feedback I am getting from most folks is "well maybe such and such should be above such and such", but they are pretty close.

We also know that quality of heat treat and edge geometry could have dramatic effects on these attributes, the chart is meant to communicate the steels potential not how a knife will certainly perform. I have a pattern that I have made/am currently making in 1095, CPM s90v, AEB-L, 52100, D2, 154 CM, 440c, CPM S110V, CPM 20CV, and CPM REX 76. All heat treated by Peters which I consider consistantly good HT. A chart like this for me is a very helpful tool.
 
I like the chart idea. I guess I like charts in general. As others have cautioned, the user needs to be aware of the factors that are not evident in the graphics. For instance, how good is the heat treat and what hardness are these steels taken to?

In spite of what's not shown, I still like the relationships depicted. While we cannot pick two adjacent steels and emphatically state one is sharper, tougher, or more stainless then it's neighbor, I think a steel from the lower tier vs middle vs top tier would give a new user valuable insites.

The user needs to be aware that there are complexities and view the charts as groups. For instance, a steel being considered could be viewed as more or less equal to another 10 percentage points up or down.

Sent from my SM-G900V using Tapatalk
 
Here is the updated toughness:

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I understand there are roughly a gajillion variables at play here, but I appreciate any and all efforts in this area. I'm barely able to follow the more nuanced steel discussions on these forums (although they are interesting), and anything that can be used to provide some basic framework of reference rocks. :thumbup:
 
If you're going to keep it going then the name "Maxamet" should be fixed. I also don't believe for one second that 10V is tougher than M4, that 01 is weaker than most of the steels on there, etc. Maxamet being as carbide rich and hard as what it should get should be nowhere near the top. I don't have the patience to go back and look at the wear resistance chart but I've played with several of them and remember some seeming out of place. Also, calling it edge retention or edge holding rankings is a misnomer. Holding an edge doing what kind of work? Edge holding to me means having the highest attainable abrasive and adhesive wear resistance along with the highest amount of impact strength and ductility combined with fracture resistance at the highest possible hardness. It seems your chart focuses on abrasive wear resistance alone.
 
bodog said:
If you're going to keep it going then the name "Maxamet" should be fixed. I also don't believe for one second that 10V is tougher than M4, that 01 is weaker than most of the steels on there, etc. Maxamet being as carbide rich and hard as what it should get should be nowhere near the top. I don't have the patience to go back and look at the wear resistance chart but I've played with several of them and remember some seeming out of place. Also, calling it edge retention or edge holding rankings is a misnomer. Holding an edge doing what kind of work? Edge holding to me means having the highest attainable abrasive and adhesive wear resistance along with the highest amount of impact strength and ductility combined with fracture resistance at the highest possible hardness. It seems your chart focuses on abrasive wear resistance alone.
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I think the chart has gotten worse. cpmD2 is second on that list? no way in hell. It will not be tougher than a lot of steels below it.
 
After a couple of updates, I still wonder how you are ranking these? Is it by gut instinct, some rather odd toughness charts, or something else? What do you mean by toughness? Are you strictly speaking of impact toughness? It still looks pretty random. One chart at a time. Corrosion resistance is next.
 
Cobalt said:
I think the chart has gotten worse. cpmD2 is second on that list? no way in hell. It will not be tougher than a lot of steels below it.
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Posted version 3 by mistake, that was supposed to be version 6. Take a look now.
 
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