O1 vs 5160

I would like to see anyone provide charts or graphs of personally performed tests.

Oh yeah, *goes to Cliff Stamp's site* *sees how well that goes over*

Something other than generalized statements would be great, on either side of the discussion. 'Oh, this one's tough' 'Ah, but this one is wear resistant' 'Yeah, but this one gets real hard' 'This has a great blend of properties for a knife' 'So does this one'
 
69_knives said:
Well, anecdotes are really interesting but could you provide some form of real world test results, charts or graphs that you have personally performed that support that statement
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I have already provided a bunch of mechanical properties data about S5 so what else do you want to know?

Non mechanical tests are highly subjective and not very repeatable by third parties.

Seems the knife enthusiasts cant agree on if the CATRA tests are valid or not, so how are you going to agree on less standardised personal tests?
 
69_knives said:
other blanket generalized statements like "Your better off using a tool steel designed for shock applications than 5160. Say, S5".
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5160 is inferior to shock resisting tool steels specifically designed to exhibit toughness and hardness. This can and has been objectively measured using proper engineering tests. 5160 provides no other exceptional mechanical properties for knife uses apart from those two mechanical properties in comparison to other materials.
 
nullack said:
I have already provided a bunch of mechanical properties data
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That's what I thought you'd say.

I've got some real knives to make and this conversation has been taken way off topic so I won't be responding to it any further.
 
Let me allay all of the confusion - I'm asking for real facts and figures, from Latrobe, Crucible or whomever. You can't simply say "Latrobe says", I did not simply say "crucible says", I gave you the book and page numbers to verify my source. Show me a source that claims S5 has the superior properties claimed other than it's jackhammer toughness - it's not hard to imagine that a steel designed for jackhammer bits is going to have a high impact toughness. Where are the "facts" that it's a superior steel in any other regard? Is it cheaper than O1 or 5160, thus making it a superior price point? Is it more stain resistant? Is it more wear resistant? Is it more marketable? Does it make ice cream for the kids on Sunday? What compromises do each of the properties come with? Are you going to claim that it is better than O1 and 5160 in every regard? Where are your sources?

Perhaps my sacrificing "everything" comment was extreme, please allow me to amend it to be "most". I do believe, however, that using a steel like S5 is a compromise of all of the other properties that concern me in order to attain an impact strength that is not necessary in a knife, even a hard use one. I have a 1095 Ka-bar that I used to baton and pry wood for camping and the only damage to it is the black finish - I think everyone here is in agreement that 1095 is not the toughest steel available for making knives, yet it survived just fine under my "real world" conditions.

Industry standard tests for wear resistance and toughness do not address the edge geometries that we deal with. What standard test can you point me to that shows S5 can produce an edge that outperforms any either of the steels asked about in the thread.

Just to be perfectly clear, I am not saying do not take information from Latrobe, Crucible or any other steel manufacturer, I am saying do not take Nullack's posts at face value. Don't take mine at it for that matter, go do your own research and prove to the world that S5 is a great knife steel. I'll accept the results if anyone can actually show me some.
 
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Does it need to be anything other than tougher? I'm not quite sure what the implied compromises are, 5160 offers nothing much in wear/corrosion resistance or marketability either:confused:. I think all it has is cost.
 
I dont have a steel religion :) I am more than happy to discuss facts and share experiences with others. I'm happy to learn, to teach others what I know, to improve my material choices and so on. If you can avoid a combative tone and not see this discussion as a contest, rather simply see this as a talk amongst fellow knife makers about the properties of S5 then you might be worth my time. Part of the problem is the internet as Im sure if you and I were talking over a barbie and beers it would be easier.

You've asked for some additional mechanical properties so:

* It can achieve a HRC hardness of 62.
* The ASM rate this using the shephard standard of having the finest grain size of 9. This can be exceeded though grain refinement techniques during heat treating.
* There is a table from a text book I have provided in the other thread that lists water and oil quenched s5 against hardness from tempering temperature, to yield and tensile strengths. This will show you the considerable strength of this material. For example 2344 mpa UTS and 1944 yield at my target HRC value.
* It has enough depth of hardening to full harden any reasonable section thickness of cutlery knives, including thick choppers .25"

I reject the idea that engineers only use what the mills suggest as applications for specific uses. It doesnt happen that way in engineering. With cutlery knives specifically, there is a temendous body of evidence showing that materials like D2 and 52100 are being used that were not ever suggested as cutlery knife steels by the mills.

And even if we ignore that, S5 is used in the tool industry in cutting applications. Some of them that I have seen are blanking knives, shredding knives, shearing knives, rotary slitters I could go on but you get my point.

Since you seem to like what Crucible have to say, please find below what they say "LaBelle Silicon #2 is a shock resisting tool steel capable of maximum toughness at relatively high hardness. It has excellent resistance to impact and battering, with good edge retention."

I manage corrosion resistance through other means. It is clear to me that stain resisting steels sacrifice far too many mechanical properties for the sake of corrosion when other effective solutions to the issue that doesnt involve crippling the steel.
 
So are you unable to provide me with these "industry standard" tests and figures that you say exist proving S5 to be superior?

If you only want a tough steel then, no Hardheart, you don't need any other properties. I am asking for someone to show me where it is superior to O1 or 5160 or any other commonly used steel in other areas. I am still waiting for this. I have no steel religion either - if one were to look around, they would see that not only do I not use either of the steels in the thread title, but other than 1080/1084 I don't generally use any oil/water hardening steels.

62 HRC is not any proof that S5 offers anything more than an ability to harden to 62RC.

I see nothing special in the grain size listed - Pg. 69 of my Verhoven text shows 5160 with and without three thermal cycles - ASTM grain size of 8.5 without thermal cycling, 14 with three thermal cycles.

Tensile strengths tell us nothing about how the edge will hold up and how fine an edge the steel will take. I have never questioned weather the steel was "strong" or "tough".

Hardening depth was never questioned either - even shallow hardening steels will sufficiently through harden - your depth is from both sides of the steel.

I am asking you once again - where are your industry standard tests, facts and figures that are going to prove to everyone here that S5 is worth considering by people who want to use O1 and 5160 and care about more than just the toughness of the steel.
 
@AcridSaint, we're just saying that S5 seems like a good knife steel, whether it would be better than O1/5160 will likely never get a consensus answer. I don't know what kind of "industry standard tests" you are looking for but I can give you my reasoning:

-The medium carbon content typically gives us excellent edge stability. At a high hardness like 60-62, it should be able to take very acute edges. This is just in theory, but this theory tends to hold up on other steels.

-What steel can't take a fine edge? I don't think we need evidence here, as it is assumed that steels can take a fine edge. Verhoven's measurements of the edges of steel show that maximum sharpness is unrelated to grain size.

-The composition suggests decent through hardening.

-Latrobe's "Practical Data for Metallurgists" make comparisions of the relative wear resistance of S5 compared to other steels.
 
AcridSaint said:
If you only want a tough steel then, no Hardheart, you don't need any other properties. I am asking for someone to show me where it is superior to O1 or 5160 or any other commonly used steel in other areas.
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And I am asking why it needs to be superior in any other area.
 
Any of the other areas I mentioned would be nice to have performance - if a steel is superior in only toughness but is a compromise in edge retention, stain resistance, cost, or any/every other factor that is a necessary consideration for a knife, why would one use it? This is not to say that all knives must have stain resistance, low cost of production, superior edge retention, etc. What it is to say is that you cannot judge a steel based solely on how hard it gets and what the charpy figures tell you, it doesn't say anything about how the knife will perform as a cutting tool and thus is not enough information to decide whether the steel is worth using over some other established material.

If S5 is vastly superior in toughness and performs as well or better in every other area than 5160 or O1, then I could perhaps see it being a viable steel, even if it performs marginally worse than these steels in some areas, it may well be a good compromise depending on application. I am asking Nullack to provide us with some proof that it does perform nearly as well, as well or better than these steels in any area other than toughness.

I didn't bring S5 into the conversation, so I don't really have any requirement to disprove his assertions. I thought that standard etiquette requires he who makes the challenge to bring the proof. Perhaps I am mistaken.
 
One thing not mentioned is that at .55% to .6% C S5 is a hypoeutectoid steel and will not have a lot of C available to form Carbides, so the wear resistance may not be as good as the HRC values may lead one to think compared to a hypereutectoid alloy like O1 or A2 that are still pretty tough. We need to weigh this into the mix when choosing a blade steel.

I doubt any S5 knife will outperform a Carbon steel hatchet.
 
Steve Hayden said:
One thing not mentioned is that at .55% to .6% C S5 is a hypoeutectoid steel and will not have a lot of C available to form Carbides, so the wear resistance may not be as good as the HRC values may lead one to think compared to a hypereutectoid alloy like O1 or A2 that are still pretty tough. We need to weigh this into the mix when choosing a blade steel.
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True, and about the same for 5160, which is kind of why I was wondering why there was any question about using it instead of the other. To me, and this is just me, 5160 is just a tough and cheap, sometimes recycled, steel. Not something to necessarily choose above anything else, just something that will work.
 
AcridSaint said:
I am asking you once again - where are your industry standard tests, facts and figures that are going to prove to everyone here that S5 is worth considering by people who want to use O1 and 5160 and care about more than just the toughness of the steel.
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And I am telling you once again the three material properties for which I have chosen this material is toughness, strength and hardness. I have given you the hard facts of what this material scores in those mechanical attributes. S5 offers the best combination of these mechanical properties in comparison to other tool steels. If you think you have found a material that exhibits better mechanical properties in these three areas by all means, show the data.

Its an absurd argument to then try and introduce vague qualities with poor definitions. There is a reason why engineers dont use terms like "edge stability". They use precise terms like yield strength, surface wear, hardness, abrasive wear. These are precise terms with standard methods for testing them. For over a century, engineers have been making cutting tools without the need for vague terms knifemakers like to throw around to appear mystical and arty, Knifemaking does not exist in a bubble seperate to physics or engineering.

When you say things like "Tensile strengths tell us nothing about how the edge will hold up" I'm sorry, and please understand I do not mean this in a negative way, but Im left with the distinct impression you should take a course on solid mechanics and dynamics. The tensile strength and yield strength *is onen of the most important factors* in keeping the dimensions of a blade from being ruined. If you try to use a knife with low yield strengths the edge will keep deforming plastically under use. Im not saying this in a negative way, but currently you clearly dont understand solid mechanics and your not equipped to make meaningful statements about it.

Beyond the objective mechanical property facts I have shared with you, like Ed Fowler, I also do a bunch of personal testing and for my knife use as I have already stated S5 has been the best material I've trialled. The problem with these tests is that it is not easily verified by third parties and is hard to replicate by others in a repeatable way. I have the objective mechanical data, but I have found my personal tests to have value as well for discerning blade performance. Ed Fowler recommends you try different materials and processes yourself to overcome the problem of personal tests. Noting that not even CATRA tests have been accepted by all knife enthusiasts as good objective cutting tests.

Steve, the compromise on this material is indeed reduced wear resistance. For the purposes of my design as I previously said, it is *far more important* to resist shattering or chipping the blade than more regularly sharpening it. I will take maintenance over catastrophic failure any day, and any serious engineer would do the same. Specifically though, the LaTrobe text that Cotdt mentioned does in fact show that the abrasive wear resistance of S5 is higher than L6 and slightly higher than S7.

Steve, what do you mean to say when you claim a S5 wont outperform a carbon steel hatched? First, S5 has both iron and carbon in it. Second, what specific performance metric are you referring to? Toughness? Strength? Hardness? While it is possible to exceed those qualities in one area, it is S5 that blends high performance of all three qualities in one alloy. Obviously the design intent of these blades is not a light duty kitchen knife - if that was so, a ceramic or more tough sintered cerment knife in say a cobalt / tungsten carbide mix would be more wear resistant.
 
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If I'm not mistaken, "edge stability" is a term coined by a German PhD in Metallurgy and well defined by his work, not a vague arty term used to describe a nebulous property.
 
Kinda, I don't know how the term has been accepted since Cliff was banned, but a lot of people hated the term and didn't care much for Landes' work when he was quoting (sometimes mis-) it. It still seems to be another way to just describe carbide tearout, Sandvik and Larrin have provided some pretty good micrographs of it.
 
Nullack - if you are saying that S5 is only good for your purpose then I must have misunderstood your intention when you started pushing it in a thread that was unrelated. Sorry for the confusion, you are completely correct, I do believe that S5 is an absolutely fine steel for the knives that you produce.
 
AcridSaint said:
Nullack - if you are saying that S5 is only good for your purpose then I must have misunderstood your intention when you started pushing it in a thread that was unrelated. Sorry for the confusion, you are completely correct, I do believe that S5 is an absolutely fine steel for the knives that you produce.
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Sorry for the confusion mate, as I said, sometimes its the internets fault cos its harder to understand what we mean than talking in person. I didnt help matters when I said that I find 5160 worse than S5, without actually typing more and qualifying that statement to say for my hard use knives. I had in my mind S5 is better than 5160 because of all these reasons I later shared, but I did not clearly communicate those in the first instance.
 
cotdt said:
@AcridSaint, we're just saying that S5 seems like a good knife steel, whether it would be better than O1/5160 will likely never get a consensus answer. I don't know what kind of "industry standard tests" you are looking for but I can give you my reasoning:

-The medium carbon content typically gives us excellent edge stability. At a high hardness like 60-62, it should be able to take very acute edges. This is just in theory, but this theory tends to hold up on other steels.

-What steel can't take a fine edge? I don't think we need evidence here, as it is assumed that steels can take a fine edge. Verhoven's measurements of the edges of steel show that maximum sharpness is unrelated to grain size.

-The composition suggests decent through hardening.

-Latrobe's "Practical Data for Metallurgists" make comparisions of the relative wear resistance of S5 compared to other steels.
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Roman Landes showed some micrographs of several popular blade steels on saturday at Ashokan that have carbides considerably larger than than 3 or 4 microns. A truly sharp blade has an edge radius of aproximately 1 micron. large carbides are exremely brittle and also readily pull out during the sharpening process leaving gaps and holes. Many finer grained steels without large chunks of carbide will sharpen to and hold a 1 micron edge. Large carbides make for good surface wear resistance they do not however contribute to fine edge stability

-Page
 
Gday Page. Mate thats an interesting take on surface engineering. It sounds like surface fatigue to me.
 
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