Trad Gang
Main Boards => Hunting Knives and Crafters => Topic started by: Scott Roush on January 07, 2010, 07:43:00 AM
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For those of you who are forging... have you ever, or is there anybody in the USA who hand forges Swedish style laminated steel? I'm talking about the stuff that consists of hardened steel sandwhiched between two layers of mild steel.
I'm curious about the process....
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Sure. Lots of the forged guys make this kind of laminated steel. It's called sanmai, although like so much, the name, being Japanese, has a broader meaning in actuality. But in this country sanmai is commonly a piece with 5 or 7 or less layers.
By the way, I think you mean high carbon steel, when you said hardened steel. My every day carry is a Ray Kirk sanmai, it's one of his pocket medicine blades. The center layer is 52100, extending down to the cutting edge.
The process is the same as any damascus, except you have to position the high carbon layer so it forms the edge. Good question. Lin
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I specifically went to a hammer-in over in Ohio this fall to learn how to do that exact thing.
I'll be using 1095 as a core and 416 stainless as the outside.
Stay tuned!
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Yeah Lin.. I did mean high carbon for the core. I was reading about how the Swedes, in the last century or so, revived their age old process of forging like this and I got fascinated.
That's great Karl.... Looking forward to hearing what you learned.
I don't forge yet, but, someday...
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Karl,
I hope to pick up a few things about that very thing. It sounds like it could be useful. Lin
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Here's one I made a couple of years ago, 5160 core between layers of chainsaw damascus. It had some flaws and the handle felt just awful in the hand. Was going to break it to see how strong it was but my nephew saw it and claimed it.
(http://i17.photobucket.com/albums/b66/Hogbear/IMG_0225.jpg)
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Hey Karl, how different is the SS/Carbon welding process from just Carbon/Carbon?
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Also Karl... if you didn't want to use stainless as the outer layer, what would be suitable as the 'mild' steel?
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Scott, it's not so much that you want a "mild" steel skin, it's that you want it to be rust resistant - which seems to be the most desired facet of current consensus.
Doug, it's a dry weld, in that no flux is used.
Surfaces need to be REALLY clean on the 3-part "sandwich". Then, rolled up in numerous layers of SS heat treating foil. This is so the layers will survive about 17 minutes up at welding heat.
Then the billet is pulled from the forge and welded.
There's actually very little "forging" done to the billet afterward. We want to keep the outer layer at a consistent distance from the edge. When you have a billet up to forging heat, the core will sort of squirt out, which is where you get the core "out" at the cutting edge.
Then, as you sloooooooooooowly forge and grind, you need to pay attention to where the skin is going and where the core is going so you end up with the desired blade.
I think a person had better be emotionally prepared for a LOT of failures, both in welding and in consistency of san mai.
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Karl... From what I've read about the Swedish style laminated steel, the idea is that you have blade that is very easy to sharpen and more durable.
This is from the description of a Frost laminated blade:
"The core of the blade is high carbon steel surrounded by a softer alloyed steel layer. A high hardness (HRC 61) can be achieved through hardening, resulting in blades with superior thoughness and cutting edge retention, thereby maximizing sharpness and long life."
However, I can also see the value of using the lamination process for providing a stainless outer shell with an 'easier to sharpen' core for the edge.
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Figured it had to be sealed, I thought about making the "sandwich" and tig-welding all the way around to seal it up.
Where did you come up with the 17 minutes and approx what temp is welding heat for SS?
Looking forward to your report on how it goes...
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The laminating process has nothing to do with the ease of sharpening. Having the outer "jacket" does not alter the hardness nor alloy of the center core.
The reason the outer layer stays soft is because it will not austenize and doesn't have enough carbon to harden when quenched.
The paragraph you have quoted is just marketing lingo.
The first sentence "The core of the blade is high carbon steel surrounded by a softer alloyed steel layer" is exactly what I described in my first reply.
By "softer" they mean it is not hardenable. They're saying this results in toughness. Ok.
Depends on WHAT that alloy is!
The benefit of the stainless "jacket" is that it adds rust resitence to the package.
There would be no reason to stop at a tough "jacket" when you could add rust prevention as well.
And, it makes a great contrast!
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What REALLY adds toughness is to leave the center core exposed on the center of the spine!
Rather than wrapping a complete jacket around the center core, you just make a three part sandwich leaving the core exposed at the top.
When the blade is quenched, we get partial martensite down through the top of the blade. This adds strength to the spine, rather than leaving it dead soft.
Some guys put in a stainless center core right where the blade begins so that the hardening STOPS at the blade/tang junction and leaves the spine drillable and fileable. etc.
Makes a nice look.
Lots of ways to go about it.
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Karl.... I'm not trying to argue with you... I just want to understand this.
I was lead to believe that the ease of sharpening of the non-stainless type of Swedish laminated steel had to do with the fact that since the outer layer is softer, then you have less hard steel to grind through when honing/grinding.
And here is another quote... Bo Bergman 'Knifemaking' a book about making Scandinavian style knives:
"... laminated blades are composed of two different materials. The internal blade is made of a thin sheet of edge steel, or hard steel, that has been hardened twice to approx. 58 Rc. The sides of the blade are then covered with sheets of soft iron and the entire piece is forged into one unit. The edge steel (core) is very hard and has a high carbon content, and the soft iron sides protect the hard center steel; thus, the knife blade is not fragile, but has high durability. This process dates back to the Viking blacksmiths, a tradition that is thousands of years old."
I guess he is saying the core is brittle and breaks easy and the soft shell does not... therefore more durable.
So is there anything to this or perhaps the thinking is outdated? And perhaps, since many of the Swedes are now making stainless blades... they are now using a process similar to what you are describing.
Anyway... As you've probably garnered from my posts, I'm pretty fascinated with Nordic knife making and I'm just trying to understand it a bit better...
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Originally posted by Doug Campbell:
Where did you come up with the 17 minutes and approx what temp is welding heat for SS?
That is the time that was arrived at by Bill Wiggins and Burt Foster.
That is the ENTIRE time - including warm up time - that the billet was in the propane forge.
The billet was placed in the forge at the same temp as regular welding temp - 2200-2400 - and then the timing began.
At 17 minutes, the billet was removed and welded.
TIGing all the way around would probably be a good way of doing it. After the first weld was done, I would let it cool off and grind off the weld.
Maybe have two billets made up so that while the first one was cooling off, you could be welding up the second one.
You might double your learning speed this way!??!
AS soon as you observed something working or not working on this first billet, it could be immediately dealt with on the second billet.
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Originally posted by mossanimal:
Karl.... I'm not trying to argue with you... I just want to understand this.
I was lead to believe that the ease of sharpening of the non-stainless type of Swedish laminated steel had to do with the fact that since the outer layer is softer, then you have less hard steel to grind through when honing/grinding.
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I realize that.
The point is that when this thing is forged down, the core SQUIRTS out from the sandwich. As you forge down your blade taper toward the edge, the center core ends up "OUT" there all by itself. There is NO "skin" there with it. The hardenable core is ALONE.
I think you believe you are sharpening all three of these "PIECES".
Hard steel is HARD steel - no matter what surrounds it. It doesn't make it easier to sharpen.
If steel was really easy to sharpen, it wouldn't hold an edge - would it?
I'm going to copy another maker's blade and post it here so you can see what I'm referring to.
What is sticking out here is plain ol' 1095 fully hardened. It sharpens just like a blade made of 1095 all by itself.
(http://i28.photobucket.com/albums/c247/kbaknife/The%20Game/bf2-1.jpg)
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That makes sense.... I just took a close look at my Frost Mora blade (laminated high carbon - not stainless) and you can see a similar thing along the edge.
So.... what is the benefit of the Swede's process then???? A lot of people make a big deal out of the Helle and Frost blades...
(btw.... thanks a lot of engaging in discussion with a rank newbie on this stuff)
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Are you suggesting that the "Swede's process" is somehow more beneficial than the one we're discussing here?
It's the same process.
Some people like Fords. Some people like Chevys. And some people like Saabs and Volvos..
I suggest that the people who "make a big deal out of the Helle and Frost blades" probably work for Helle and Frost.
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Originally posted by mossanimal:
That makes sense.... I just took a close look at my Frost Mora blade (laminated high carbon - not stainless) and you can see a similar thing along the edge.
What you are looking at there is MARKETING!
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Maybe the same sort of process... but different materials. The process I'm referring to uses what is called 'soft iron' on the outer layer. You are talking about using stainless. I understand the benefit of the stainless process you've been talking about... That makes a lot of sense... But what I'm trying to understand is the idea of using the 'soft iron' outer core and the hardened inner core... the process that has made Swedish blades famous. In other words... why are the high carbon (non-stainless) laminated blades from Sweden considered so good by so many people?
Maybe it is just marketing.... I dunno... I'm obviously in over my head here!
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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?
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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.
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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:
(http://i28.photobucket.com/albums/c247/kbaknife/The%20Game/laminate.gif)
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.
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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???"
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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!
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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.
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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.
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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.
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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.
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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...
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"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!
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well I obviously do not have a grasp on the benefits anymore.... so you may be right: it sure looks good!
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"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.
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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!
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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?!! :-)
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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.
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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)?
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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......
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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.
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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.
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I just don't understand that "ease of sharpening". It just does NOT matter what's on the outside.
The center core is still there and needs to be sharpened and is HARD!
If that center core is easy to sharpen, it is NOT because of the outside. It's because they have tempered it to be so.
Putting two pieces of soft pine on either side of a piece of oak does not make the oak easier to cut through.
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But there is a lot less hard stuff to work through. Like I said... It probably doesn't help much with 'ease of sharpening' but I just wanted to point out that with flat grinding there is a lot of wearing down of the outer layer... unlike the examples you showed. I just bring it up because that was one of the reasons you thought the 'ease of sharpening' issue was bunk.
Seriously... We don't need to keep going on this! I just thought about it this morning as I was waking up.
Thanks again for schooling me on this issue. I learned a ton from it.
Oh by the way.... I found a forge (Pinewood Forge)in northern Minnesota that makes these kind of knives - they are what he calls Scandinavian wood carving knives and they are laminated steel - what he calls '01' high carbon/high alloy tool steel. I can't tell if he is actually forge welding the steel or if he is buying the steel and doing stock removal.