forging laminated steel

[Scott Roush]

I just read some stuff on Ragnar's website and it starting to come through now.  I guess it's just what I alluded to before... those knives have a harder edge (higher Rc than a lot of the knives out there) with the benefit of less brittleness due to the soft outer core.

So is this still just marketing, or from a metallurigical standpoint, does this hold up to reality?

[Wampus]

Japanese swordsmiths have been using low carbon outer layers to encase higher carbon centers on samarai swords for centuries.  I'm no blade historian, but the "Swedish process" sounds a lot like the Japanese process from over a thousand years ago.  
I was told/taught that it's so you can have a hard cutting edge in a sword that won't snap from being too brittle.  The lower carbon outer layer adds toughness and protection for the hard core.

[kbaknife]

Your use of that phrase "high carbon" concerns me.
The core material we use is just as high in carbon as the ones the Swedes use.
You may want to read this link here:
 http://www.ragweedforge.com/helle/h-blades.html
In the very first sentence you will see:
"Most Helle blades are made of triple laminate stainless steel. The center portion is of high carbon stainless steel* , hardened to 58-59 HRC. This is the harder part of the blade that holds the edge. The outside layers are tough 18/8 stainless."
I hope we can see this little picture:
It shows stainless outside and "high carbon" stainless inside:
 
It is not "maybe the same sort of process" - it is the EXACT SAME PROCESS.
It doesn't make any difference what that outer core is!
The only part of the Swedish blades that is HIGH CARBON is the core, just like the ones we're doing and just like the one I posted above. No difference.
You are trying to find a difference where none exists.
The benefit to what we've described is that we use stainless for more rust protection, if in fact, the knives you refer to are using non-stainless, but in light of the above reference, it seems even Helle is now using stainless outside.
There is also availability of materials, and the Swedish laminated blades more than likely pre-date stainless steel, and are a continuation of tradition more than anything else.
Stainless didn't even get perfected until the early 1900s, and Swedish laminated blades are far older than that.
I would rather have one made like we are currently doing with a stainless outer jacket.
To answer your question, the "laminated blades from Sweden" are considered good because they are good.
They are being sold and marketed to an entirely different market of people than the ones who buy individually crafted blades/knives.
Don't even for a second consider that what we make is in ANY WAY inferior to what the 'big boys' make. Sometimes, quite to the contrary. Being made by one person, one knife at a time, our knives are often faaaaaaaaaaaaar superior to what can be bought at -------knife Mart.
But these companies are in business because they are good at what they do and are making great knives!
Just don't think they are superior because they can buy full page ads.

[Scott Roush]

When I said 'high carbon' above, I was only distinguishing their carbon blades versus their stainless. Unless I misspoke somewhere in the thread... I've always understood that the core is high carbon and never thought that it was different than ours (although it appears to be hardened to a higher degree than a lot of ours... hence the idea of having the soft outer core to preserve it's brittleness). It's the outer core that I've been wondering about - either the 'soft iron' of the traditional laminated blades or the stainless that you've been talking about.

The stainless Helle blades are a relatively new thing going there. If you look at other parts of his website you will see where he talks more about the traditional carbon blades that they've been making for a long time.

But I agree with you.... the folks that prefer the traditional blades may be a hold back to the times when stainless was much more difficult to hone. Bo Bergman, in his book, also mentions that he is starting to see the benefits of the stainless laminated blades.

I didn't mean to imply that those blades are superior to everything made here!  I was just interested in why people seem to make a big deal about them.  And I also wasn't only referring to the Frost and Helle blades. Bo Bergman has examples of incredible hand forged traditional laminated blades made by individual smiths. Which is the reason I started this thread! I was wondering if there were Americans who forged blades this way.  Apparently there are and they are using stainless instead of whatever 'soft iron' is.

Wow.... this has been confusing but I think I understand it all now. Thanks!

Wampus... Yes. I was starting to put that together and one of next questions was going to be: "What is the difference between the japanese laminates and the Swedish???"

[kbaknife]

We're not done yet!
You are making a distinction between "high carbon and stainless".
They are BOTH "high carbon" or they would not be hardenable.
They both have the same amount of carbon! Stainless is high carbon, too, when used to make cutting blades.
The only difference is the amount of chromium to give them stain resistance, which slows down the conversion rate and makes them air hardenable.
The distinction should be stainless and non-stainless.
I also don't understand your comment, "I've always understood that the core is high carbon and never thought that it was different than ours (although it appears to be hardened to a higher degree than a lot of ours... hence the idea of having the soft outer core to preserve it's brittleness)"
The Helle blades are 58-59 RC. So are mine.
The softer out core does NOT prevent any brittleness.
Brittleness is controlled in the TEMPERING process.
Once again you suggest that "people make a big deal about them".
They are good, so they deserve praise. I guess I just am not familiar with the "big deal" that you suggest.
I do know they work well and are affordable, so maybe that's worth promoting.
Here's soft iron:
"Iron comes in two forms, hard and soft. If you were hit on the head with a soft iron bar, it would still feel very hard; soft is simply a term describing the magnetic properties."
It has to do with the iron's ability to be demagnetized in the making of magnets.
I have a bunch of wrought iron and may use some of that in the near future on both Damascus and San Mai.
This has been fun, actually.
Thanks for bringing it up!

[LC]

Well heres my humble opinion! And I'd like to go on record here saying I don't want to pass any one off. Your talking about sandwiching stainless on the outside of high carbon or even having stainless as the core of a sandwich. For me personally I've got a old AMERICAN made Buck 110 folder made out of SOLID stainless steal that is realitvely easy to sharpen and will butcher several deer before needing resharpening. What more can the average sportsman need? Corrosion resistant, easy enough to sharpen for anyone willing to do it and great edge holding properties for anyone IF they don't abuse the edge no different than HC steel. Now this knife probably would not pass any bladesmith tests of chopping 2x4's, rope, water bottles, bending to 90 degrees, etc etc but what it will do will gut skin and butcher 3 deer before needing resharpened.

Now anyone will tell you that knows me I LOVE HC steel, especially old files and ancient saw blades made into knives as I've been doing this for years, etc but I will say this I've got the all the materials to make a electric kiln oven to  precisely make stainless steel knives and soon (this weekend if we get the snow forecasted) that will be my main or only interest in knife making. Stainless got a bad rap from cheap chinese steel years ago when it first came out but it's came a long long way baby! Is it as great as HC steel heck no but the pros far out way the cons for every day use. Again just my humble opinion your mileage may vary.

[kbaknife]

Stainless is FANTASTIC!!!! You are going to have a ton of fun!.
I have a Buck 110, too, and it spends a great deal of its life on my belt.
The name alone, says a LOT.
Buck got the heat treatment right, which is the whole idea behind the ease of sharpening and edge retention.
I made stainless knives for 6 years. Just got tired and bored with cutting and grinding away "everything that didn't look like a knife".  
I just couldn't stand being restricted in my blade size/dimension/profile by the bar I started with, and watching so much of my steel ending up on the shop floor. And, it's expensive!
I bought so many band saw blades I went broke.

[Scott Roush]

Yeah... I should have made that distinction (stainless versus what I was calling high carbon). I guess I knew that in concept but I wasn't applying it in this discussion.

As to the actual hardness... it appears that Helle blades are becoming much different animals that the traditional ones.  I've been looking at traditional swedish laminates that are 62 and above.  I understand that the softer outer core doesn't prevent the brittleness of the harder inner core, but it acts as a tougher sheath right? Protecting the brittle core? Same concept as the japanese blades right? Anyway... that is what I meant.

LC... I'm new to this, but from what I've been learning, it sounds like the newer generation stainless steels are far superior to the old stuff. Having said that.... non-stainless high carbon has it's benefits too... so why not pursue perfection and wed the two? I'm getting into this by doing stock removal, hopefully I will start forging within the year, and after that I would love to have the talent make these laminates.

[kbaknife]

Originally posted by mossanimal:

  I understand that the softer outer core doesn't prevent the brittleness of the harder inner core, but it acts as a tougher sheath right? Protecting the brittle core? Same concept as the japanese blades right? Anyway... that is what I meant.

.... non-stainless high carbon has it's benefits too... so why not pursue perfection and wed the two?

Harder does NOT mean brittle. That inner core is not brittle. If Helle made brittle blades they wouldn't be in business.
In view of what we are making, the outer layer of stainless acts as a barrier between the austenized 1095 core and the quench oil, thus the steel UNDER the outer layer reverts to softer pearlite because the oil was not able to cool it fast enough to make martensite. Only the exposed cutting edge gets hardened and the "brittleness" is removed during the tempering cycles.

[Scott Roush]

lol!!! Just when I thought I understood! well then I'm at a loss! This is obviously out of my scope right now. Really... I'm not being sarcastic... I'm just realizing how little I understand about all this. I was lead to understand that hardening steel makes it brittle and tempering makes it a little less hard and less brittle but still hard enough to hold an edge. So what is the benefit of making these laminated blades if it isn't to take advantage of hard steel providing an excellent edge material encased by the less brittle outer layer providing durability??? Isn't this what Wampus in his respose above also alluded to with the japanese blades??? I mean... I understand the actual exposed edge in the Helle knives are tempered and not brittle...

[LC]

"non-stainless high carbon has it's benefits too... so why not pursue perfection and wed the two?"

 Simply because the very thing or the inherent or concieved "problems" of HC steel that your despartly trying to cover up still are exposed on the very thing, THE EDGE, the very reason you use a knife to begin with. Like I said I absolutely love HC steel but just don't understand this wedding. Still I see at it as a absolute art form and if thats what your going for by all means go big!

[Scott Roush]

well I obviously do not have a grasp on the benefits anymore.... so you may be right: it sure looks good!

[LC]

"made stainless knives for 6 years. Just got tired and bored with cutting and grinding away "everything that didn't look like a knife".
I just couldn't stand being restricted in my blade size/dimension/profile by the bar I started with, and watching so much of my steel ending up on the shop floor. And, it's expensive!
I bought so many band saw blades I went broke."

Not to sound cruel but I'm glad you got bored, cause you have learned and taken knife making to a level most of us just have to sit back and say WOW! You make incredible knives that are not just drop dead gorgeous but functional as well. My  short billed hat( bowhunter first here) is off to you! Seriously you have my utmost respect and I read and then reread everything you have to post here. I just wish I knew what you've forgotten.

[Ray Hammond]

and remember mossanimal, you aren't honing the stainless...its not on the edge of the sanmai blade.

And when you get done learning about this, then there's WOOTZ to study as well!

[Scott Roush]

I understand that... where did I say that? I mentioned somewhere that stainless is harder to hone than non stainless... that's just common knowledge... but definitely I have the concept down that the core and edge is NOT stainless.

I think there might be a lot of miscommunications going on here! What have I gotten myself into?!! :-)

[kbaknife]

Originally posted by mossanimal:
lol!!! Just when I thought I understood! well then I'm at a loss! This is obviously out of my scope right now. Really... I'm not being sarcastic... I'm just realizing how little I understand about all this. I was lead to understand that hardening steel makes it brittle and tempering makes it a little less hard and less brittle but still hard enough to hold an edge. So what is the benefit of making these laminated blades if it isn't to take advantage of hard steel providing an excellent edge material encased by the less brittle outer layer providing durability??? Isn't this what Wampus in his respose above also alluded to with the japanese blades??? I mean... I understand the actual exposed edge in the Helle knives are tempered and not brittle...

I'd say you understand it quite well by your above statement, of course, that is if you understand what you said.
Sort of reminds me of that statement "I know you think you understand what you thought I said, I just don't know if you understand that what I said is not what I meant."
Actually, understanding the terminology of basic knife steel heat treating and metallurgy is of the utmost importance when discussing this "stuff".
One steel alone is hard enough to figure out, but then when we start talking about pattern welding damascus and san mai applications of more than one dissimilar steels and how they effect each other, things get amplified dramatically!
I think we did good.

[Scott Roush]

Okay.... I'm not quite sure I understand any of this anymore... but one more thing and I can put this to rest: What is, in your opinion, the benefit (other than beautiful patterns) of laminated steel (whatever the outer layer is)?

[kbaknife]

Originally posted by mossanimal:
I understand that... where did I say that? I mentioned somewhere that stainless is harder to hone than non stainless... that's just common knowledge... but definitely I have the concept down that the core and edge is NOT stainless.

I think there might be a lot of miscommunications going on here! What have I gotten myself into?!! :-)

That's another thing - the stainless on the outer "jacket" of the san mai Ray is referring to is NON-AUSTENITIC stainless steel! Meaning, it won't harden. It's SOFT stainless. It is NOT hardenable.
That's what I will use on my laminated steel.
So, you need to be sure when you say "stainless" that you mention what grade of stainless you are referring to.
When it comes to hardening steel, whether it be air hardening, water/brine hardening or oil hardening, in other words stainless, shallow hardening or deep hardening, it's best to know the BASICS of setting the steel up for the hardening process, controlling grain size, proper control of temps to properly turn the steel into austenite and then using the proper method to convert the austenite to martensite, and all of this followed by the proper tempering method to relieve the stresses and end up with the correct hardness for that knife type, considering the steel used.
Get all of the words and terminology defined and the rest sort of becomes easy.
It doesn't happen overnight, and I just barely got the book opened.
It's a hoot and a lot of fun to be had!
Just jump in and find out what you don't know, then look for a way to figure that out.
Then find the next thing you don't know, and on, and on, and on......

[kbaknife]

Originally posted by mossanimal:
Okay.... I'm not quite sure I understand any of this anymore... but one more thing and I can put this to rest: What is, in your opinion, the benefit (other than beautiful patterns) of laminated steel (whatever the outer layer is)?

The way I will laminate it is that the vast majority of the blade surface requires no attention - it's pretty much rust free.
A quick wipe of the edge and put it away. This can be of great benefit on a weekend long hunting or camping get-away.
As well, the marketing aspect of it in that it is visually appealing. Each blade as unique as Damascus.
With properly controlled grain size under the stainless "jacket" the 1095 I will use should be sufficiently tough, too. Because I will leave the 1095 at the spine exposed and get some martensite there, too, if I do my job right. This will add to the lateral toughness of the blade.

[Scott Roush]

Well I can't wait to see your first blade and it seems like a great way to make a blade.

Not to start this up again but... I just thought of something about the whole 'ease of sharpening issue'. The traditional scadinavian laminated blade is almost always flat ground. When you sharpen flat ground knives you have to lay the blade pretty much flat on the stone.  This means you definitely grind off the outer layer every time you sharpen.  On my Eric Frost knife, you can see the inner layer and it is only a couple of millimeters away from the edge and you can see the outer layer peeling back every time you grind.  So... this may contribute to the idea that they are easier to sharpen? Probably not... but that outer layer does get hit.