I made this and thought I would share

Chris Railey said:
Nevermind, I do not know why I bother...
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I'm not sure this should be the conclusion, I think it's a good idea. But as Mr Wilson mentioned above, there is a risk of someone taking this out of context, which could lead to further disputes or people not trusting the information from this forum.
 
Chris Railey said:
Nevermind, I do not know why I bother...
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Chris, if you're still reading this - you "bother" because you like helping other folks and we all do appreciate your work. This thread could lead to a very good discussion about sources and how they differ in HT info. Two of my most respected folks are Larrin Thomas (also his Dad of course) and Kevin Cashen and most of the time they both agree on HT info. There are a couple of times when their written info does conflict - and I suspect there is more to do with typo than anything.

We'd LOVE to have you back :)
 
KenH said:
Chris, if you're still reading this - you "bother" because you like helping other folks and we all do appreciate your work. This thread could lead to a very good discussion about sources and how they differ in HT info. Two of my most respected folks are Larrin Thomas (also his Dad of course) and Kevin Cashen and most of the time they both agree on HT info. There are a couple of times when their written info does conflict - and I suspect there is more to do with typo than anything.

We'd LOVE to have you back :)
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I agree, let's just make it a healthy discussion instead of an argument as to who or what is correct. I'll take in all the information I can get and sort it out for myself by trial and error. I don't think there are many hard fast rules for this sort of thing. There are general guidelines and great info from well respected makers, but nothing is written in stone...
 
CDHumiston said:
I don't think there are many hard fast rules for this sort of thing.
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I'm not sure I agree. After all, we are dealing with physical materials that should have known properties. So the folks who study this should be able to know what the "right" answer when they can control as many variables as possible. One of the problems is, do we really know all the variables in the shop/forge setting?
 
CDHumiston said:
I agree, let's just make it a healthy discussion instead of an argument as to who or what is correct. I'll take in all the information I can get and sort it out for myself by trial and error. I don't think there are many hard fast rules for this sort of thing. There are general guidelines and great info from well respected makers, but nothing is written in stone...
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Actually for heat treating, it's one of the few areas there ARE more hard and fast rules.
 
J. Doyle said:
A lot of industry recommendations for steels don't necessarily have the knifemaker and the cross sectional geometry of a knife in mind when they publish those specs.
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I would bet that the bottom of the list is knifemakers. We don't really buy alot of steel is the overall scheme of things. So with that in mind I'd expect some variation in the specs, but if you were making car bumpers , not so much.
 
I'll offer my opinion on why heat treat numbers vary from source to source.

Manufacturers are offering heat treating recommendations for a product, not heat treating instructions for a particular batch of steel that was rolled and annealed and delivered in a specified condition. Right now, on my bench, I have multiple ht'd blades in 8670, ht'd on the same same. In that batch, I had (1) blade that was cut from .100" and (3) that are from .125". Both from AKS, typically received with very little decarb, and one could assume that they were milled very similarly by their appearance. The .100" blade is 58 HRC from tip to tip with no discernible deviation across multiple tests. The .125" blades all hit 61 HRC average across all tests. 1525/375. I suppose if I were a manufacturer I might run different ht schedules until I could put those two samples in together and get similar results. I'd bet my money that a higher heat (like is often cited from data sheets) would probably do that.

I've had similar experience with 80CrV2. Across several different heats, it would respond differently. I now run my 80CrV2 out to 15 minutes at 1525 and the results are absolutely consistent from batch to batch.
 
Bruce McLeish said:
I would bet that the bottom of the list is knifemakers. We don't really buy alot of steel is the overall scheme of things. So with that in mind I'd expect some variation in the specs, but if you were making car bumpers , not so much.
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thanks for not agreeing with this statement, even though most of my stuff does look like aforementioned auto bumpers. Perhaps I should get a discount on steel. (or bumpers)
 
Bruce McLeish said:
thanks for not agreeing with this statement, even though most of my stuff does look like aforementioned auto bumpers. Perhaps I should get a discount on steel. (or bumpers)
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Well I kinda do agree with that, generally speaking. How small time knifemakers ht treat knives probably never enters the conversation when they decide what data to publish for most steels.
 
I did check the tempering temperatures for the 8670 on Knife Nerds and you're not even close with the tempers you listed. You could go there or to ASM International. Those temperatures were glaringly different from the other steels that you listed and it seems to me that you had the responsibility to check it out.

Doug
 
Doug Lester said:
I did check the tempering temperatures for the 8670 on Knife Nerds and you're not even close with the tempers you listed. You could go there or to ASM International. Those temperatures were glaringly different from the other steels that you listed and it seems to me that you had the responsibility to check it out.

Doug
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Did you or anyone else feel compelled to read AKS' comments or data on that subject at the link? I screen capped it for you.
1C275016-E101-4DC7-83D5-74C30E4A0FC6.jpegE14FE21D-0F84-4E11-8262-265394B16F98.jpeg
 
tkroenlein said:
Did you or anyone else feel compelled to read AKS' comments or data on that subject at the link? I screen capped it for you.
View attachment 78904View attachment 78905
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Did you or anyone else feel compelled to look just above that at the steel/alloy composition and wonder why are we using austenitizing numbers nearing or in the normalizing range, given the composition?

And what if we compared that to 15n20?

And I also noted that they openly state that Larrin was very helpful in providing testing and information for that steel. And yet apparently (I haven't personally verified) the numbers are drastically different than what Larrin suggests.

Why is that?
 
Interesting they only mention "Quench in Oil" with never a word about what oil. Parks 50 quench oil? AAA quench oil? Canola oil? Burnt motor oil?

J. Doyle said:
Why is that?
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That is a question I asked early on, and gave temps from different knifemaker sources and asked why the temps varied so much.
 
Let me be clear....I'm not saying I have definitive answers to some of this....but I sure have questions.

Looking at composition of 80crv2, 15n20, 8670 and L6, I sure can't understand how there is a precise temp of 1480 F. given for 15n20 but a much higher range of 1560-1615 given for 80crv2 and even higher range for 8670.

I can't see, from my limited experience, why 1480 would be good for 15n20 but up to 1635 for 8670 would be recommended.

And there is the aforementioned discrepancies in tempering temps. It doesn't add up.
 
As I posted earlier, I suspect there are reasons manufacturers and mills suggest ht schedules, and that's a least common denominator approach to their product based on various conditions that it's delivered in.

It doesn't make sense to me, either, apart from the first hand experience of having two different thicknesses of the steel in question that don't respond to the same heat treat. I'm sure there are differences between the two from the mill.

I'm really only jumping in here because we moved right past discussing ht source discrepancies to it's wrong to assigning responsibility to Chris Railey to debunk a steel mill's ht recommendations that are advertised and tested by a trusted steel retailer.

I started following Larrin when he had only a few articles out. When I felt ashamed of continuing to use all the good info he was putting out for free, I joined up in Patreon. I read all of his posts on BF and the FB pages he visits. I paid money for his book. His free dissemination and effort to make it available moved myself and countless other noobs ahead by years in our ability to make knives of respectable quality. But never in anything he's written does he claim his stuff is gospel. It is often quoted as such. In fact, my takeaway is quite contrary to that. I believe he wishes to teach people how to work up a heat treat schedule and adjust for the conditions with which they are presented, and provides mountains of data on how that is accomplished.
 
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