Book on metallurgy and knifemaking by Larrin Thomas

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Enactive » Tue Sep 08, 2020 7:57 am

Cambertree wrote:
Sun Sep 06, 2020 5:29 am
I received mine!

Image

Back when I was getting into the knife hobby more deeply, I did a fair bit of reading of John Verhoeven, Cliff Stamp, Roman Landes, and Sal of course - and others.

This is the resource I wish I’d had back then.

And I’m very glad we have it now. :cool: :)

I see it’s not the first time my volume has appeared on these pages, though! ;)
Enactive wrote:
Sat Aug 01, 2020 1:38 pm
I was pleased to get mine yesterday. I have only started to read a bit of it, but looking forward to spending more time with it soon.

IMG_20200731_163156.jpg
Thank you brother - your kind and gracious gift is very much appreciated! Cool postcard too... :) :cool:

I’d also be keen to see Larrin do some research into the H1 SE questions that I’m sure many other members are also curious about.

Is SE H1 harder towards the edge, and if so, by how much?

If the steel in a finished blade exhibits a kind of ‘differential hardness’ due to rolling and machining, then what hardnesses and difference in microstructure are displayed from spine to edge?

How does SE H1 compare to other steels in CATRA testing, like VG10, GIn-1, MBS26, CTS-BD1N and S30V, when they are ground identically?

Is there any difference at all in SE H1 edge apex hardness after the knife has been extensively used and sharpened?

If I recall right, Sal may have mentioned that they have some H1 in Golden to make Autonomys with, and he could be open to sending a piece to Larrin for testing?
Cambertree,

I am glad you have the book now-- and i can imagine it sure would have been nice to have it earlier! :D :p

We're all just fortunate to have Larrin participating and producing work like this! Of course the previous work by Landes, Verhoeven, Stamp... and so many others has been huge too. I need to backfill some of my knowledge gaps! :eek: :cool:

I-- along with a bunch of others-- would be enthused to see some further testing and analysis of H1! What the heck is going on with that mystery metal. It isn't even steel, right (not containing carbon)? Just some bizarre iron alloy? :p

As i wrote on the card, you will have to come visit and see the Olympic Mountains and elk for yourself some day.

Cheers, mate!

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby sal » Tue Sep 08, 2020 7:31 pm

FYI, Dr. Verhoven and Al Pendray had complete use of our CATRA machine for a week testing Wootz, many years ago. Peter ran many tests for them.

sal

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Enactive » Tue Sep 08, 2020 7:45 pm

sal wrote:
Tue Sep 08, 2020 7:31 pm
FYI, Dr. Verhoven and Al Pendray had complete use of our CATRA machine for a week testing Wootz, many years ago. Peter ran many tests for them.

sal
Thanks, Sal! I should have included you in my incomplete list. :D

I appreciate that you shared your equipment and are sharing that bit of history with us. :cool:

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Wartstein » Wed Sep 09, 2020 12:25 am

Cambertree wrote:
Sun Sep 06, 2020 5:29 am
.....
Enactive wrote:
Sat Aug 01, 2020 1:38 pm
....
......
I’d also be keen to see Larrin do some research into the H1 SE questions that I’m sure many other members are also curious about.
....
Is there any difference at all in SE H1 edge apex hardness after the knife has been extensively used and sharpened?
....

Well, more insight into H1 would be very appreciated!

I´ve asked several times already how this H1 - work hardening thing precisely works and what is actually really happening there - but even very knowledgeable members could not fully explain it to me (which might very well be due to my own limitations! :) ) on a "microstructure" level...

I am even more curious to learn more on this since like many others in "real life" I just do experience how amazingly long H1 in SE holds an edge - but still don´t fully grasp WHY this is.
Top three going by pocket-time: Endura 4 in VG 10/Micarta-scales; Stretch 1 in VG 10; Endura 4 in HAP 40

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Larrin » Wed Sep 09, 2020 8:29 am

I think I have said enough about H1 for now. Most of the questions being asked about H1 I already answered. Maybe people didn't like the answers. https://knifesteelnerds.com/2019/06/24/ ... -it-works/
http://www.KnifeSteelNerds.com - Steel Metallurgy topics related to knives

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Cambertree » Wed Sep 09, 2020 10:16 am

Larrin wrote:
Wed Sep 09, 2020 8:29 am
I think I have said enough about H1 for now. Most of the questions being asked about H1 I already answered. Maybe people didn't like the answers. https://knifesteelnerds.com/2019/06/24/ ... -it-works/
I did read that article Larrin.

I’m still puzzled by a couple of things, though.

The high hardness which Crucible’s testing reported at the edge for serrated edge H1, would seem like some sort of anomaly, from your explanation. Do you think this warrants any further investigation?

So do you think the increased edge retention of SE H1 over PE H1 is purely down to the more acute edge angle, thinner behind the edge thickness, and the way the serration points and arcs engage the cutting media?

I’d still be interested to see a CATRA comparison of a SE H1 knife to an identically ground serrated knife in a martensitic stainless, like VG10 perhaps?

Given the increased difficulty of grinding serrations on a couple of test samples, I wonder if Spyderco has made the same model before in both SE H1 and a serrated martensitic steel, which could be used for testing?

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Larrin » Wed Sep 09, 2020 11:29 am

Cambertree wrote:
Wed Sep 09, 2020 10:16 am
The high hardness which Crucible’s testing reported at the edge for serrated edge H1, would seem like some sort of anomaly, from your explanation. Do you think this warrants any further investigation?
Not particularly. The original claim of higher hardness at the edge didn't make much sense and an independent measurement did not confirm it.
So do you think the increased edge retention of SE H1 over PE H1 is purely down to the more acute edge angle, thinner behind the edge thickness, and the way the serration points and arcs engage the cutting media?
The experiments that were performed to support the claim that H1 has superior serrated edge performance have not been shared so it is impossible to speculate. We don't know what edge geometries were tested, what comparisons to other steels were done, or even how much better the H1 tests were. Without knowing any of that we don't know that the H1 did perform better than other steels.
http://www.KnifeSteelNerds.com - Steel Metallurgy topics related to knives

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Cambertree » Wed Sep 09, 2020 4:19 pm

Thanks for your thoughts, Larrin.

The earliest reference I can find regarding those Crucible tests on serrated H1, seems to indicate that the measurements were actually microhardness tests of some type.

So I had wondered whether they may have indicated a shallow surface hardness of untempered martensite which was formed by the knife grinding operations, after the aging process from the foundry?

Presumably there must be some surface level of untempered martensite formed by the knife grinding operations, as the H1 knives need to be given that simultaneous hollow grind on both sides to prevent warping in production. Or am I in error on this?

Yes, I guess I’m just curious about the H1 SE ‘apples to apples’ comparison, as that steel in that edge configuration is often discussed here.

Many of your other pieces have dealt definitively with subjects which used to be debated back and forth in the knife world.

My own anecdotal observations:

The test which is refererenced about H1 having the highest CATRA test results for a Spyderco model at the time, were specifically on the Jumpmaster. That model has a very high, thin hollow grind apparently, as well as presumably the usual Spyderco SE inclusive edge angle of around 16-17 degrees.

Many other high carbide, high hardness steels have been used in Spyderco models since then, so they weren’t compared at the time.

Most mentions of SE H1 edge retention seem to be comparing it to PE in the same steel. From memory, an increase of about 4 times is mentioned. This might sound more impressive because H1 in plain edge is towards the lower end of the wear resistance scale.

Any steel in SE cuts significantly longer than PE in the same steel (as long as the edge is stable in SE in the first place).

So SE H1 probably also performs very well in comparison to martensitic steels in plain edge.

In my own (very anecdotal ;) ) observation and use, steels like Gin-1, and VG-10 seem to outcut H1, when they are all in serrated grinds. Of course, these are in different knives, albeit all Spyderco hollow ground SE models.

Thanks again for all the work you did in researching and writing your book.

I’m still reading it, but I just wanted to say, I much prefer the book format to the website post format.

The diagrams and images are very useful to explain concepts to people who I’m teaching to sharpen.
Last edited by Cambertree on Thu Sep 10, 2020 7:25 pm, edited 1 time in total.

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Cambertree » Thu Sep 10, 2020 7:20 pm

Enactive wrote:
Tue Sep 08, 2020 7:57 am
Cambertree,

I am glad you have the book now-- and i can imagine it sure would have been nice to have it earlier! :D :p

We're all just fortunate to have Larrin participating and producing work like this! Of course the previous work by Landes, Verhoeven, Stamp... and so many others has been huge too. I need to backfill some of my knowledge gaps! :eek: :cool:

I-- along with a bunch of others-- would be enthused to see some further testing and analysis of H1! What the heck is going on with that mystery metal. It isn't even steel, right (not containing carbon)? Just some bizarre iron alloy? :p

As i wrote on the card, you will have to come visit and see the Olympic Mountains and elk for yourself some day.

Cheers, mate!
Thanks again, my friend. :)

Yes, Larrin’s book is an excellent resource, which I highly recommend to anyone who is interested in delving into the subjects relating to knives on more than a surface level.

Occasionally friends and friends-of-friends who use edged tools for their work or hobbies, will ask me to do a session with a group, explaining the basics of sharpening, different sharpening setups and maintenance etc. I also give them some basic info on steel metallurgy and microstructure, and have an assortment of documents and images I use for this purpose.

Larrin’s book is now a single reference work that I can use for these sessions. Of course it’s much more than that, but I’ve been enjoying showing people the micrographs of their knife steels, diagrams of different edge grinds, and the scanning electron microsope images of edge apexes etc.

Yes, H1 is an austenitic steel - I can’t think of any other examples of non martensitic steels used in knife blades. I think Cliff Stamp did some experiments on sharpening and using an austenitic grade, some years ago, if I remember right.

Visiting the the Olympic Mountains and the Pacific Northwest and seeing Elk would be amazing! The landscapes are so different to Australia. Thanks again, and likewise, I’d be honoured to give you a guided tour around my part of Australia if you ever travel here again. :) :cool:

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Larrin » Fri Sep 11, 2020 8:51 am

Cambertree wrote:
Thu Sep 10, 2020 7:20 pm
Yes, H1 is an austenitic steel - I can’t think of any other examples of non martensitic steels used in knife blades. I think Cliff Stamp did some experiments on sharpening and using an austenitic grade, some years ago, if I remember right.
It is true that H1 is an austenitic stainless. However, it is largely martensite after processing for high hardness.
http://www.KnifeSteelNerds.com - Steel Metallurgy topics related to knives

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Cambertree » Fri Sep 11, 2020 9:17 am

Larrin wrote:
Fri Sep 11, 2020 8:51 am
Cambertree wrote:
Thu Sep 10, 2020 7:20 pm
Yes, H1 is an austenitic steel - I can’t think of any other examples of non martensitic steels used in knife blades. I think Cliff Stamp did some experiments on sharpening and using an austenitic grade, some years ago, if I remember right.
It is true that H1 is an austenitic stainless. However, it is largely martensite after processing for high hardness.
Thanks for the clarification Larrin, that’s very interesting.

So from reading your article, the martensite is largely formed from milling and rolling the H1 sheet down from approximately 7mm to whatever thickness is required for making knives - say 3mm. Then there is an aging process at the foundry to temper the martensite.

But once the processed sheet is sent to Spyderco, would it be true that there would be a small amount of untempered martensite formed at the surface level, from the grinding and polishing operations used to make a blade?

Thanks, I’m just trying to understand this further.

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Larrin » Fri Sep 11, 2020 1:45 pm

Cambertree wrote:
Fri Sep 11, 2020 9:17 am
But once the processed sheet is sent to Spyderco, would it be true that there would be a small amount of untempered martensite formed at the surface level, from the grinding and polishing operations used to make a blade?
Maybe, if they are using poor grinding and polishing operations there would be superficial work hardening which could transform retained austenite. Or it could just work harden the martensite. But if they are getting significant superficial (surface-level) work hardening then they would be having some issues. And once you sharpen the edge that would be gone.
http://www.KnifeSteelNerds.com - Steel Metallurgy topics related to knives

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Cambertree » Fri Sep 11, 2020 6:54 pm

Larrin wrote:
Fri Sep 11, 2020 1:45 pm
Maybe, if they are using poor grinding and polishing operations there would be superficial work hardening which could transform retained austenite. Or it could just work harden the martensite. But if they are getting significant superficial (surface-level) work hardening then they would be having some issues. And once you sharpen the edge that would be gone.
Ah, thanks for the further info, Larrin. :)

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Rp5 » Sat Sep 12, 2020 11:31 pm

Image

Just received my copy. Thanks Doc.

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Enactive » Sun Sep 13, 2020 10:07 am

Cambertree wrote:
Thu Sep 10, 2020 7:20 pm
Enactive wrote:
Tue Sep 08, 2020 7:57 am
Cambertree,

I am glad you have the book now-- and i can imagine it sure would have been nice to have it earlier! :D :p

We're all just fortunate to have Larrin participating and producing work like this! Of course the previous work by Landes, Verhoeven, Stamp... and so many others has been huge too. I need to backfill some of my knowledge gaps! :eek: :cool:

I-- along with a bunch of others-- would be enthused to see some further testing and analysis of H1! What the heck is going on with that mystery metal. It isn't even steel, right (not containing carbon)? Just some bizarre iron alloy? :p

As i wrote on the card, you will have to come visit and see the Olympic Mountains and elk for yourself some day.

Cheers, mate!
Thanks again, my friend. :)

Yes, Larrin’s book is an excellent resource, which I highly recommend to anyone who is interested in delving into the subjects relating to knives on more than a surface level.

Occasionally friends and friends-of-friends who use edged tools for their work or hobbies, will ask me to do a session with a group, explaining the basics of sharpening, different sharpening setups and maintenance etc. I also give them some basic info on steel metallurgy and microstructure, and have an assortment of documents and images I use for this purpose.

Larrin’s book is now a single reference work that I can use for these sessions. Of course it’s much more than that, but I’ve been enjoying showing people the micrographs of their knife steels, diagrams of different edge grinds, and the scanning electron microsope images of edge apexes etc.

Yes, H1 is an austenitic steel - I can’t think of any other examples of non martensitic steels used in knife blades. I think Cliff Stamp did some experiments on sharpening and using an austenitic grade, some years ago, if I remember right.

Visiting the the Olympic Mountains and the Pacific Northwest and seeing Elk would be amazing! The landscapes are so different to Australia. Thanks again, and likewise, I’d be honoured to give you a guided tour around my part of Australia if you ever travel here again. :) :cool:
That's very cool that you do those workshops for friends and friends-of-friends. Paying it forward and sharing knowledge and skills together like that is very rewarding. It will be excellent to be out of the pandemic when we can do such things safely and easily in-person. I finally ordered up some CBN rods and a doublestuff 2! :cool: :spyder:

You would be a most welcome guest here too when it is allowed again. I do certainly hope to travel to OZ again someday and will be sure to be in touch.

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby sal » Sun Sep 13, 2020 10:19 am

We stand on each others shoulders so we can see farther. Thanx much Larrin for the extra view.

sal

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Larrin » Sun Sep 13, 2020 5:09 pm

sal wrote:
Sun Sep 13, 2020 10:19 am
We stand on each others shoulders so we can see farther. Thanx much Larrin for the extra view.

sal
The book certainly wouldn’t have been possible without all of those before me who have made their contributions to the study of steel and knives. Always building on prior knowledge to be higher than we were before.
http://www.KnifeSteelNerds.com - Steel Metallurgy topics related to knives

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Larrin » Tue Oct 20, 2020 9:47 am

I updated the book by correcting typos and adding conversions to Celsius throughout the book. I would call it a "revision" rather than a new edition. Purchases from Amazon are now the new revision.
http://www.KnifeSteelNerds.com - Steel Metallurgy topics related to knives

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Ankerson » Tue Oct 20, 2020 10:18 am

Larrin wrote:
Tue Oct 20, 2020 9:47 am
I updated the book by correcting typos and adding conversions to Celsius throughout the book. I would call it a "revision" rather than a new edition. Purchases from Amazon are now the new revision.

How did it make it past the Publisher with typos?

Nobody proof read it before printing?

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Re: Book on metallurgy and knifemaking by Larrin Thomas

Postby Larrin » Tue Oct 20, 2020 11:18 am

Ankerson wrote:
Tue Oct 20, 2020 10:18 am
Larrin wrote:
Tue Oct 20, 2020 9:47 am
I updated the book by correcting typos and adding conversions to Celsius throughout the book. I would call it a "revision" rather than a new edition. Purchases from Amazon are now the new revision.

How did it make it past the Publisher with typos?

Nobody proof read it before printing?
Unfortunately, finding every typo in a 450 page book is difficult. There were still 3 or 4 remaining.
http://www.KnifeSteelNerds.com - Steel Metallurgy topics related to knives


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