HT blade with wrought iron clad

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Nov 7, 2013
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I recently acquired a power hammer, a 25lb "Canadian giant"! So,. the first thing I did was jump in head first and bang out a piece of a huge wrought iron spike I had . When that seemed to work out ok I figured I'd try to sandwich it with a piece of sawmill blade., then that worked out too so I kept going until I eventually had a knife.

Now. My problem. I heat treated the blade as I always do with the sawmill steel when I use it, in an Evenheat at 1500, canola at 130, temper 2 hours at 400 twice. Always worked decent before. After post HT grinding however I noticed the blade will bend, and not spring back. The edge is hard, but I also know I didn't expose the carbon steel for the quench.. I never thought of that until after the fact.

SO. My question.. Do you need to grind past the outer steel clad on a blade like this to allow the core steel to harden? (it sounds so obvious in my head now) Or, if the core IS hardened, is it staying bent because it is too thin, and the soft clad isn't allowing it to spring back?
 
The core is hard and springy but the wrought iron on the sides is not so if you bend it the thin spring inside is not strong enough to force the wrought iron back straight. This is why San-Mia is tough becaus the cladding is not hard and won't crack but it would spring back ether. Just because something is tough does not mean it's good for knives
 
A desirable trait for a sword though. A bent blade can be straightened and you can continue fighting. A broken blade makes for a very bad day...
 
It's a balancing act, if the core is thick enough, it won't bend as easily, but you won't show as much of the cladding with full height grinds. Thicker blades the ratios are easier to maintain, it's why you won't see many san-mai pocket knife or really thin blades, with soft cladding by western makers.


However, many/most Japanese knives are made this way, it's a part of their knifemaking tradition to use thin hard cores and have knives be straightenable by hand. I've always been curious whether this came about from material economy, simply being frustrated with straightening (which has affected all of us at some point or another), simply as an extension of the sword making construction choices, or some other reason. Like much in Japanese culture, I think the authoritative answer is likely lost to traditionalism and history.


For the kinds of knives I make (thin, small, and utility oriented), I don't think this is a desirable trait, so I rarely utilize this type of material personally, even though I think it looks super cool.
 
A desirable trait for a sword though. A bent blade can be straightened and you can continue fighting. A broken blade makes for a very bad day...

Yeah, but that's only one method of skinning that cat, there's plenty of ways to accomplish the same thing without laminated construction with non-harden able cladding. I'm only posting this response lest someone read your post and come to the conclusion that "it's necessary to make swords out of san-mai for them to be tough enough to not break", which is how myths get proliferated in this field. No offense. ;)
 
I thought you had to quench a sword in the the pee from a read headed virgin while facing north? But this is only after increese the density of the edge by edge packing.
 
From my understanding, the Japanese did not have a lot of access to iron ore or the advanced furnaces the western world had discovered. Therefore, bits of high carbon steel were more rare and valuable because they only made up a small percentage of the bloom. By making a blade with minimal high carbon steel through san mai techniques, you are able to create a nice blade that can keep an edge.
 
From my understanding, the Japanese did not have a lot of access to iron ore or the advanced furnaces the western world had discovered. Therefore, bits of high carbon steel were more rare and valuable because they only made up a small percentage of the bloom. By making a blade with minimal high carbon steel through san mai techniques, you are able to create a nice blade that can keep an edge.

Thanks for the information, that's kind of always been my top expectation for the answer also. In fairness, much of the history of "steel edged tools" has similarities. It's interesting to consider the transitional points of time where for instance, labor became more valuable that materials, which for the bulk of history was the opposite. It's something that is brutally obvious in our trade as knifemakers, wearing so many hats now that were once a specialty of many different craftsmen, who all worked together to create the final product of a "knife".
 
Certainly in older times laminated blades arose because steel was far more precious than iron. However, it's not merely tradition that keeps Japanese makers producing laminated blades. The bevel of a laminated blade is far easier to thin on stones than a monosteel knife. This is why many chefs in Japan (and the West) like these kinds of knives, since you can more easily maintain an optimal cutting geometry.
 
Certainly in older times laminated blades arose because steel was far more precious than iron. However, it's not merely tradition that keeps Japanese makers producing laminated blades. The bevel of a laminated blade is far easier to thin on stones than a monosteel knife. This is why many chefs in Japan (and the West) like these kinds of knives, since you can more easily maintain an optimal cutting geometry.

Eh? I'm gonna have to disagree with this. Yes, typical Japanese grind type and edge geometry *does* make it easier to maintain edge geometry, by simply laying the entire bevel on a stone. However, this is much more material to remove than the secondary bevel on a western style grind (and you still have to abrade the hard part, in a much longer cross-section), and as someone who made, and worked with a massive amount of this type of material, I can tell you, that having secondary softer steel, isn't an advantage when grinding or sharpening, it's a burden. Having two dissimilar hardness metals makes cutting inconsistent, the soft material loads the abrasive much worse, "pulls" itself into the abrasive, causing inconsistent cutting speed, and you're still going to have to cut the hard steel, no different than if it's mono.

You could in fact argue, that having half the cutting bevel laying on the stone being hard, and the rest soft, that it's *MORE LIKELY* to cause you to cut more into the soft material, producing a mild convex to that bevel, as opposed to maintaining a flat angle.

It's also highly contentious whether in knife sized tools, there's ANY advantage other than saving material and making straightening easier to use this type of construction. I would argue that from an objective view, mono-steel is a much superior construction methodology, since if you straighten it properly before and during HT, it will maintain better rigidity (less likely to flex in cuts, which is usually a boon, except in the rare specialty tasks where flexibility is required), and should *never* take a set of plastic deformation after this. A fully hard, mono-steel knife in the hardness ranges we typically use, especially in high end kitchen cutlery, will not, if properly HT'd exhibit plastic deformation and take a set, before breaking. i.e; You should *never* need to straighten it.

Do you propose there's some reason you'd want to bend a san-mai knife out of straight, and then back to straight? I've never heard of this type of use, nor can I think of any scenario where this would be advantageous. Yes, you can bend a soft-clad knife back straight if it becomes bent, but a properly HT'd mono-steel fully hardened (and even reasonably differentially tempered) blade, will never need to be straightened, unless it was improperly HT'd or straightened in the first place.


*Regardless* if it takes you more than 5 minutes to touch up a blade (swords excepted, I'm talking knives), you're waiting too long, or trying to do too much work with too fine a stone. Yes, if you neglect to maintain an edge, it can take hours, but it should never get to that point in the first place.

I've also *never* heard a knife user tell me they preferred a laminated blade for this reason. I deal with numerous pro chefs, butchers, etc. Many of them prefer Japanese cutlery (usually just because they have some ethereal "feel" and pop-culture knowledge that it's "inherently better"), although most of them aren't even aware of the soft cladding of the laminated construction.


Sorry, not trying to be argumentative here, but your assertion just doesn't grok for me, and it rings of trying to come up with ideas to justify your preferences. If you prefer Japanese style cutlery, there's nothing wrong with that, I like it also (don't make it myself, but I enjoy it, as a vastly different approach to the tools we all know and love), but please try not to make blanket claims without any explanation, that's going to proliferate misconceptions.
 
I guess we're going to have to disagree here. If you look at most Japanese single bevel blades, there actually is supposed to be a slight convex to the bevels. Yanagibas and usubas, for example, are supposed to be sharpened with a slight hamaguriba (convex edge). The softer cladding allows you to more easily sharpen back into thicker sections and raise the shinogi line. In this, I guess our experiences are just different. I find it much more pleasant to thin tall laminated bevels on a stone vs monosteel and haven't noticed loading problems, etc.

It's important to emphasize, I'm talking about thinning, not merely sharpening. I have nothing against monosteel. Many chefs prefer it. But monosteel knives will eventually have to go back to the maker for thinning (and this is often done in Japan). A Japanese sushi chef is more likely to thin his laminated yanagiba as he sharpens; that's simply the sharpening culture over here.

There is a backlash, I think, against the hype of Japanese knives. We have gone from "ooh, they make their blades like samurai swords and that's why they're the bestest" to, "they blindly follow tradition, and there's no logical reason for the way they do things." Perhaps both assertions are wrong?

EDIT: I should add, that I agree with you about plastic deformation. Being able to easily straighten post-HT makes the knife maker's life easier, but it definitely doesn't make it a better knife. However, it's also not necessarily a problem for the knife user, if the blade geometry is done right.
 
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I guess we're going to have to disagree here. If you look at most Japanese single bevel blades, there actually is supposed to be a slight convex to the bevels. Yanagibas and usubas, for example, are supposed to be sharpened with a slight hamaguriba (convex edge). The softer cladding allows you to more easily sharpen back into thicker sections and raise the shinogi line. In this, I guess our experiences are just different. I find it much more pleasant to thin tall laminated bevels on a stone vs monosteel and haven't noticed loading problems, etc.

It's important to emphasize, I'm talking about thinning, not merely sharpening. I have nothing against monosteel. Many chefs prefer it. But monosteel knives will eventually have to go back to the maker for thinning (and this is often done in Japan). A Japanese sushi chef is more likely to thin his laminated yanagiba as he sharpens; that's simply the sharpening culture over here.

There is a backlash, I think, against the hype of Japanese knives. We have gone from "ooh, they make their blades like samurai swords and that's why they're the bestest" to, "they blindly follow tradition, and there's no logical reason for the way they do things." Perhaps both assertions are wrong?

EDIT: I should add, that I agree with you about plastic deformation. Being able to easily straighten post-HT makes the knife maker's life easier, but it definitely doesn't make it a better knife. However, it's also not necessarily a problem for the knife user, if the blade geometry is done right.


As long as we both have reasons for our opinions, and are willing to explain them, I think it's not just ok, but good, to have differing views. I'm glad you took my response as a desire for constructive dialogue, as was it's intent.

In this public forum, it's really not important for us to agree, more that our views are laid out with details as to why, so that the less knowledgeable on-lookers can come to an informed decision themselves, as opposed to blindly reading "This or that is just better", and then going around repeating that without a foundation of reason, as their "opinion".



As to what we were originally discussing, what you're saying makes sense, and as you say, much of it is preference. Personally I'd just rather go to a more aggressive stone to thin out the bevel(honestly I think people that aren't makers are much too afraid to mess something up, by jumping to an appropriately coarse abrasive), or, back to the grinder, but obviously my view, and the area of focus for this area of the forum, is from an equipped "Knifemaker's" standpoint.

I'm also interested in the perceptions about Japanese knives/makers, and I agree, that neither extreme regarding their perception is fair/accurate. The reality, most likely, is somewhere in between. To be fair, there is huge deference to traditionalism in Japanese culture, and a resistance (in the modern base cultural default) by the mainstream Japanese to question that. I worry that many Japanese smiths, and (as I see very often) Western, Japanese Cutlery enthusiasts, and makers trying to emulate that style, don't understand the basis of these traditions, and defer to them with almost religious reverence.

There are outliers however, I've definitely seen some really innovative Japanese knifemakers in the last decade.

Anybody that knows me, will tell you, that I am not the type of person that thinks there's any one "right way" to do anything, and I try to be really open minded that not only, is my style, not universal, but we *NEED* all kinds of makers, and knives, in this field. I often look at a knife of another maker, where I don't personally enjoy the aesthetics, but it's important to be impartial, and evaluate based on skill, talent, and intent, regardless of whether I find the form itself to be "right". However, based on my overt individualism most likely, I can not tolerate, doing something a certain way, simply because someone was told, that it's the "way to do it", and because of reverence, that not only being repeated, but vehemently defended, without any basis.



I am, without any doubt, that most of the traditions in Japanese cutlery, came about from pragmatic necessity. I do have big doubts however, if many of them remain, for any reason other than traditionalism, and whether many of the smiths even know the reasons.

Western makers are just as guilty, and have failed to educate their customers also. I can not tell you how many makers and collectors, believe the Ricasso of a knife is simply an antiquated, aesthetic tradition, and think that traditional style makers are simply following that blindly. Nothing could be further from the truth, but even the people that are supposed to know why they use this construction method, don't understand why, because they're deferent to whatever "great maker" they learned from. The Ricasso however, is the foundation of a knife, in the most literal since. It's the index point for straight, parallel, and center. It exists for very good reason, and it amazes me that anybody who understands the slightest history of this craft, could think otherwise. The masters of previous centuries didn't do much, without a really good reason.


Of course, with all crafts and trades, there are always a large contingent of it's practitioners, that simply "learn" one thing, one way of doing something, and repeat it, into infinity (or they die.) It's understandable, sometimes you simply want things to be simple, and get consistent results, unfortunately, at least to me, nothing in this art is ever simple, and trying to force that, ultimately dilutes it, and proliferates misconceptions.


Ok well, we've fully derailed the OPs post. Tenebr0s, if you ever want to discuss knife philosophy or the East/West cultural divides further, please don't hesitate to email me. javan.dempsey@gmail.com
 
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