Rehashing "flex"

Sunshadow, maraging steel first does not contain carbon so if you're particular it's not technically steel. It combines MARtensite + AGING [precipitaion hardening] as the two hardening mechanisms. It is iron +large amounts of nickel and some cobalt and molybdenum.High strength ,toughness and fatigue strength are it's main features. As far as fencing it works significantly better than steels commonly used though at significantly higher cost. The swords I looked at were made of 9260.
 
"Why would you want to do that? I just can't bring myself to throw something out that might be usefull someday. I think I'll just keep them all handy. Just in case." Jason

... We must not have anything better to do. :(
 
mete said:
Sunshadow, maraging steel first does not contain carbon so if you're particular it's not technically steel. It combines MARtensite + AGING [precipitaion hardening] as the two hardening mechanisms. It is iron +large amounts of nickel and some cobalt and molybdenum.High strength ,toughness and fatigue strength are it's main features. As far as fencing it works significantly better than steels commonly used though at significantly higher cost. The swords I looked at were made of 9260.
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Thanks Mete that explains what I was experiencing with it.

-Page
 
"Intuition is all right, but let’s not get carried away," Kevin R. Cashen

Intuition is mathematical. :D
 
…I personally think that using less technical language, at times, would allow more people to both understand and participate in the discussion. Again; a picture is worth a thousand words, especially to those not versed in the subject being discussed.
If I am speaking in front of a crowd, on a subject that I know well, I tend to use language that I am comfortable with. That language does not always inform those that I am speaking to.
If my purpose is to educate, I have found that using language they can understand, along with visual aids, is more beneficial to them learning.
After all that is why I am there. As a teacher, I am not there to impress them, I am there to teach them.
Thanks again for what you have taught me. I appreciate it very much, Fred
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Fred I don’t know why but this post has stuck with me and troubled me. I have always shared your views in this topic and have always gotten very good feedback in any of my presentations for communicating rather complex topics in down to earth and easy to understand terms, your is the first complaint I have ever received that I had failed in this area.

It is particularly frustrating because I am caught between a serious rock and a hard place here. If I don’t use the exact, precise technical terms and carefully cover all the aspects, there are folks who are just waiting to pounce on the slightest misspelling in order to have their pound of flesh, and yet if I don’t bring it all down to street level I will lose some folks who find the technical jargon boring or distasteful. So I can try to be precise and hope to keep folks attention or I can distill it down and run the risk of having the whole thing picked to death by slide rule jockeys with a chip on their shoulder.

I know exactly what you are saying because I have always HATED it when techno geeks seem to get some sort of self validation by beating people to death with huge words and feel any commoner daring to speak the sacred tongue must be taken down a peg. Having a low tolerance for anything but the exact precise wording, only tends to lose people, or turn them off entirely. I have always felt there was a gap between the average guy who wants to know some of this stuff and the high handed pseudo-intellectuals who are more concerned about intimidation than actually sharing information. My goal has always been to bridge that gap. But whenever I start a chat such as this I am always waiting for somebody who just finished an engineering class who needs some sort of egocentric validation to start stomping all over the discussion. I personally am not impressed with folks who can only regurgitate textbook technobabble like a parrot, as I am never convinced they actually know how to apply those terms they simply learned by rote.

I feel it takes a more secure person to work with people with whatever terms they are comfortable, (it also takes a pretty good understanding of the subject). You have no idea how many times I have heard .8% on the Fe-Fe3C diagram referred to as the “eutectic”, but I am a big boy capable of knowing what they are saying even though they used the wrong term, later in a private moment I will point it out in a fun way so that they don’t continue with the error. But why derail a decent conversation because I feel I have to prop up my ego by jumping all over a miss-applied term that didn’t affect the general point in any way?

For ages the best way for the elite to keep common people under foot has been to deny them access to knowledge. In the middle ages the ability to own and read books was what separated those in power from their thralls. Guttenberg started perhaps the biggest revolution of them all by introducing the world to widely disseminated knowledge for all. But those old methods live on in anybody who seeks to be superior to others through a monopoly of knowledge and refusing to allow any rosetta stone to give their exclusive language to the common man. This topic can be VERY technical and could have been handled with voluminous equations and undecipherable technobabble if the goal was to make all us silly little bladesmiths feel stupid or gain an upper hand through intimidation. However the spirit behind it was to make valuable information accessible to anybody present in a casual manner; to rob the elite of their power over us.

I guess what I am saying is that I like folks who talk simply and have lots of good questions much more than pompous people who talk down to us with $5 words, and the fear of ever sounding like one of them drove me to write the preceding paragraphs to clarify my position and to offer my apologies if I ever become one of those windbags.
 
I say the more technobabble the better. If I don't understand what is said or know some of the terms I will look it up or ask. If I wanted to hear someone talk about things I already know and understand I would just talk to myself more :D

The great thing about this forums is that there are people at all different levels interacting and helping each other. Someone like Kevin or Mete can come in and drop a bomb full of big words and a few people will get it right away, some will get it after those people break it down a little more, and some won't get it until they have gone out and learned some of the basics. Eventually everyone that cares to will understand.
 
Let me try with two sentences of 2 cent words.

If you take three steel bars of equal geometry and composition, each with different heat treating (one hardened, one hardened and tempered and one annealed) they will "flex" (bend and return to true when the load is removed) equally, under an equal load,... up to a point, (the limit of the elastic range of the annealed bar). After that point the heat treating will show very dramatic differences.
 
Kevin,

Sorry about the lag. Modem died. I used to write letters. I may start again.
I am a kinesthetic learner and a frustrated one at that. I was the guy that got straight A's in lab and flunked the coarse.
I built my five port digitally controlled, blown and argon injected, heat treat oven from the pictures in my head. It holds set temperature within 3 degrees.
Pencil never touched paper throughout the project.
Intuitive thinking, as Tai Goo calls it.
If I had found the plans, for it, in a book; it never would have gotten built.

I read all of your post with great relish. I know there will be information contained in them that will both benefit me and that I will find interesting.
Putting the technical language together so that my mind will grasp it is another thing entirely.
It would be a little more intelligible, if it were auditory.
I am a person that learns in motion so to speak
The human mind is such a complex thing!

Sorry, there was no offense meant.:eek::D

Please keep posting your well thought out tutorials. They are read and appreciated by many; but please, keep us picture learners in mind, if you would.

Fred
 
Kevin you hit the nail on the head. I have been filleting fish for 45 years and not only do you not need a flexible blade, for me it seems like theres more control on that rib cage
when the blade does not flex.Now I can hear the argument coming about removing the
skin from the fillet
Ken.
 
Fascinating discussion! I am neither a knifemaker nor a metallurgist. I'm a mathematician.

We have a similar division amongst us, the geometers and the algebraists. The geometers are "visual" people. They need to be able to visualize the solution (as in the geometry of it) to a problem before they can accept it, even when they know it's right. The algebraists are the opposites. They need to be able to prove a solution via a formula before they can emotionally accept it.

What is funny is that both sides will admit to something being right, but need to see it in their own terms before they truly "believe" it in their heart. There have been many major advances to mathematics by people from both sides.

It's interesting to see both sides in other disciplines as well. They complement each other very well!

Back to my beer and dutch master's cigar.... :D
 
Forgive my ignorance, I am really enjoing this thread,
Lemme get this straight: Geometry, thickness, and material used determines flex not heat treat. So when we remove brittleness via tempering does that simply reduce the chance of breaking upon vibratory impact? Or am I totally missing the whole point?
I personally, am a very tactile person. I have to (and have been) read this several times for it to sink in. Either way, thank you for taking the time to share this knowledge in the name of improving the craft.
 
While I will always welcome the opportunity to re-open an old thread, particularly one that needs reiterating as much as this topic, I would like to ask if it constitutes some sort of double jeopardy for me to have to put out the same resulting flames I dealt with 9 months ago??;)

The idea that heat treating can in any way affect the stiffness of steel is so strong that it is perhaps at the very top of my list of "Commonly accepted facts that are totally false." We could resurrect old threads continually but it may be better for folks just to go to the library or invest in some simple books on physical properties of metals or basic engineering.
 
Kevin, I want to see if I've retained any knowledge at all....you know, I've slept since then.

So, without looking back through the thread, Stiffness represents how much force is needed to deflect a given thickness of steel. Blades of the same geometry will deflect at the same time. The heat treat only effects how far each sample will give before it takes a set or before it fails.

Am I right....I'll look back through the thread and grade myself!

--nathan
 
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… just go make some knives and try them out!

What I’m saying is,… Who can’t tell if a blade bent, sprung or snapped? Golly gee, we must all need to go read a few more metallurgical volumes at the library to figure that one out… I mean duh!

If you can't get this stuff with plain old observation and common sense,... you shouldn't be playing with knives in the first place. LOL :D
 
Forgive our silliness, Tai. While it is true that learning through the process of observation, hypothesis, and testing in the real world is the base form of gaining knowledge, some of us nerds like to discuss the technical nature of things that can't be observed through the simplist of observations :D. For me, it's always been more fascinating to learn "WHY" things happen after learning "WHAT" happens.

--nathan
 
Ok, so I've edited my original post and I'll ask the question here to make sure I get it right. The part I took out was "stiffness if uniform for all steels" because I was not sure of the answer. I'm not sure where I got that, but for the same geometry, will all blades deflect with the same force reguardless of steel type?

--nathan
 
Here’s what Kevin said recently on another thread which I think sums it up quite well:
Differentially hardened blades can be aesthetically pleasing and are worth it for the artistic hamon aspects; they will have a higher ductility and increased toughness on the spine. This will however be at the expense of much of the over all strength. The differentially tempered blade will have a better overall strength with less of an increase in ductility and toughness in the spine, and less chance of fine pearlite in the cutting edge. The fully quenched blade will have the highest strength, very little ductility and whatever toughness the alloy and tempering schedule imparts, and with good control over final edge hardness. Of course none of the above will have any effect at all on the stiffness of the blade, which is determined entirely on the grinder; that is just the way it works.

The edge quenched blade will have is usefulness decreased as it takes a set under a much lighter load but will not break (if everything is done right). The fully hardened blade will be useless when subjected to a load perhaps eight to ten times what it takes to bend the edge quenched blade, and it breaks. The differentially tempered blade is somewhere between maximum strength with non-ductile failure and maximum ductility with non brittle failure.
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Here’s how Ed Caffrey explains it, worded slightly different (semantics and perspective) but in essence is the same:
As for myself, I prefer the edge quenched/differentially heat treat blade for a user. When I utilize that method of heat treating, it gives me much more latitude creating the blade. I can control how stiff or limber the blade will be, and give it a host of other characteristics that I could not if the same blade were fully hardened. Thats not to say I don't fully harden some blades....I do. Each has its place in my shop, depending on the given blade and its intended uses.

If I were building myself a multi-purpose or camp type knife, it would be differentially heat treated. I personally would rather have a blade that if bent, could be straightened (with a rock if necessary) and keep using it, versus a fully hardened blade that if pressed to the breaking point....I would only have two (or more) pieces of steel that would not be of much use.
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I don't even think about this stuff anymore,... It just seems to come to me naturally... :)
 
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