Performance: Forged vs Stock Removal

[Kevin R. Cashen]

Can anything be proved?

To me, as i read, i am getting factual knowledge here, that leads in a circular way.. ending up with no definitive answer, having many variables (or maybe im not paying close attention) .

The "why".

What about grain refinement, from forging, or the advantages offered by multiple quench, thermal cycles. These are not imaginary, surely? (traditional methods) .. they've been employed for hundreds of years, possibly?

Forging, shatters the crystalline grain structures, refines the steel. Creates a matrix, in differentially heat treatment, gives toughness and strength, right?

And, stock removal knives cannot be differentially heat treated?

i have a rudimentary knowledge of all This, but a lot still a lot of questions, myth and fact.

If this this is wrong, why? David

David, the possum asked a most critical question,as you may be surprised how many people really do not want the answers to quite a few of the questions you pose. If you would like to discuss the facts behind many of them, feel free to e-mail me.

 

[2knife]

Thanks Kevin. Will do.
David

 

[Michael Lovett]

Can anything be proved?

To me, as i read, i am getting factual knowledge here, that leads in a circular way.. ending up with no definitive answer, having many variables (or maybe im not paying close attention) .

The "why".

What about grain refinement, from forging, or the advantages offered by multiple quench, thermal cycles. These are not imaginary, surely? (traditional methods) .. they've been employed for hundreds of years, possibly?

Forging, shatters the crystalline grain structures, refines the steel. Creates a matrix, in differentially heat treatment, gives toughness and strength, right?

And, stock removal knives cannot be differentially heat treated?

i have a rudimentary knowledge of all This, but a lot still a lot of questions, myth and fact.

If this this is wrong, why? David

1. The grain is already as refined as it is going to get from the foundry. At least in it's un-heat treated state. Further refinement will be gained in the heat treating. Not under the hammer. It must be stress relieved to reduce the stress put into the steel from the hammering. The hammering or forging, in and of it's self can do nothing to imp[rove the steel. Indeed great care must be exercised to more and more damage to the steel. The forging it's self at its best, can only hope not to damage the the steel. It is for moving and pre-shaping the steel. Nothing more. Of course, there is welded steel. But that is another topic altogether.

2. Multiple quench, and multiple draws do indeed work. I was the first known maker to champion the triple draw back in the very early 70's. It is common place today. And I am mostly stock removal. Either of us can doand do research Heat treat and steel performance. No one has an exclusive on it.
For many years we research metallurgy and heat treat. Bob Loveless was the first knife maker of modern times to explore modern steels and Exotic Heat Treating.

3. The breaking up of the crystalline structure is one of the myths I was alluding to earlier. Along with edge packing.:jerkit: And the packing and or breaking up of molecules. (Must have been a hydrogen bomb hammer.) It was part of the smoke and mirrors used as sales pitches for years. And I'm sad to say, Still is at the big shows. And especially at the Big gun shows.

4. And on a lighter note. As to the forged knife having a soul, as opposed to any other method. I doubt that you could catch a soul and hold on to it in the first place. And if you could, I doubt you could get it to be still long enough to pound it into a piece of red hot steel. From what I've heard, Souls tend to try and stay away from hellishly hot places! Especially for the long term!

 

[severedthumbs]

1. The grain is already as refined as it is going to get from the foundry. At least in it's un-heat treated state. Further refinement will be gained in the heat treating. Not under the hammer. It must be stress relieved to reduce the stress put into the steel from the hammering. The hammering or forging, in and of it's self can do nothing to imp[rove the steel. Indeed great care must be exercised to more and more damage to the steel. The forging it's self at its best, can only hope not to damage the the steel. It is for moving and pre-shaping the steel. Nothing more. Of course, there is welded steel. But that is another topic altogether.

2. Multiple quench, and multiple draws do indeed work. I was the first known maker to champion the triple draw back in the very early 70's. And I am mostly stock removal. either of us can do it.
For many years we research metallurgy and heat treat. Bob Loveless was the first knife maker of modern times to explore modern steels and Exotic Heat Treating.

3. The breaking up of the crystalline structure is one of the myths I was alluding to earlier. Along with edge packing.:jerkit: And the packing and or breaking up of molecules. )Must have been a hydrogen bomb hammer.) It was part of the smoke and mirrors used as sales pitches for years. And I'm sad to say, Still is at the big shows. And especially at the Big gun shows.

4. And on a lighter note. As to the forged knife having a soul, as opposed to any other method. I doubt that you could catch a soul and hold on to it in the first place. And if you could, I doubt you could get it to be still long enough to pound it into a piece of red hot steel. From what I've heard, Souls tend to try and stay away from hellishly hot places! Especially for the long term!

Well said Lovett. :thumbup:

 

[stephanfowler]

3. The breaking up of the crystalline structure is one of the myths I was alluding to earlier. Along with edge packing.:jerkit: And the packing and or breaking up of molecules. (Must have been a hydrogen bomb hammer.) It was part of the smoke and mirrors used as sales pitches for years. And I'm sad to say, Still is at the big shows. And especially at the Big gun shows.

This is something that hits home with me in a big way.

I UNDERSTAND that there is no physical way to effect the grain structure of steel with a hammer, i get it, really i really really do. i promise.

IMHO the statements re: edge packing and breaking up molecules is actually very viable, true, and HONEST. NOT smoke and mirrors.

look at it in a historical context. before Galileo it was KNOWN that the world was flat, there was reasonable scientific data to support this conclusion. There were very HONEST scientists and philosophers that supported the FACT that the world was flat. (keep reading, i'll try and make sense in a minute) Then some upstart young punk came along and started challenging the old school assumptions saying that the world WASN'T flat, it was in FACT round. and not only that, but the sun DOESN'T revolve around our paltry little rock called earth. looking back, NO ONE can argue that the world is flat and not be seen as a complete idiot, because we now have verifiable evidence that the world is round. Does that mean Socrates, was a dumbass................. really, is that what your trying to imply.

no Socrates was a brilliant brilliant man, who ALWAYS challenged the status quo, but in his limited abilities would have agreed with the ASSUMPTION that the world was flat, simply because it was the most reliable and correct way to "precisely explain the world around him"

thats really what science is really about, reliably OBSERVING and EXPLAINING the physical world around us.

I don't look back at the knifemakers who USED to claim that hammering could change the grain structure of steel and laugh, I'm HONORED that they would even ATTEMPT to explain the verifiable results that they were demonstrating with their heat treat process. With their limited ability to truly STUDY what was happening, the most correct explanation was that the hammering had something to do with the results...................

NOW, the guys who still to this day claim that hammering has an effect on the grain, wake up, I mean, really, c'mon now.


bahh, enough ramble

 

[Tai Goo]

Science is incomplete...

Art and, "THE" human experience,... transcends science!

 

[gator68]

recommended by howard clark on another forum: John D. Verhoeven: Steel Metallurgy for the Non-Metallurgist

now available in hard cover from ASM International or amazon.

i haven't read it, but i'll get a copy. maybe it helps!

hans

I've read it, it's a great introduction to understanding what's going on in the steel. Full of charts and graphs.

 

[Michael Lovett]

I'm afraid that the edgepacking was disproved years ago. You simply cannot compact the molecules with the pressures from a hammer. As to breaking up molecules., they are much smaller Much, Much smaller than the grain. It would be impossible to break metal on at molecular level with a hammer. A Nuke could do it.

This is exactly what I've been talking about. These myths an misconceptions have been around so long that even many of the makers have been duped into believing it. And honestly have no problem teaching the customers all about it. It isn't always hucksters doing it. Many of the makers still to this day, truly believe these myths.

Problem is, the human mind tries to explain what it doesn't understand. This is how myths are born. There is nothing wrong with using science to research what is really happening. Magic aside.

And no T. It doesn't dispel the need for research. If it did, we would still be arguing about whether the earth was round or flat. Fast forward a few centuries my friend. We are waiting on you!


Mike

 

[Broos]

I enjoy both the scientific and the soulful artistic makers. And don't forget the old world type craftsmen guys who are just great technicians. I even enjoy simple knives from neophyte makers sometimes due to some raw appeal. There is enjoyment in all those aspects for me. Thank goodness all you makers aren't the same, and don't agree about everything, because the world is richer just the way it is.

In school I always thought there was something kind of soulful about the study of steel - to me metallurgy was much more of an empirical class, where the science is built upon observation more than based on theory. Materials Science (composites more than anything) was just the opposite, very theoretical and math intensive. It struck me things I thought would be similar were so different. Maybe that is an analogy to some makers? We know a lot more about a lot, compared to not very long ago, and knowing that should help us avoid thinking that we know everything, because we don't.

As an aside, there are methods to examine steel and find internal voids & inclusions using ultrasonic and radiography (X-ray and gamma rays) methods. They are not cheap, but using them is a good investment for nuclear reactor parts & pieces, pipeline welds, and other very critical parts. Also other methods are used to find flaws on the surface which are not able to be seen without help - mainly cracks. Certainly not essential for knives.

But I sure would like all my knives to come with a slip showing what the edge hardness tested out at Rockwell C!

 

[2knife]

Friction, Pressure, and Heat.. (sort of like this thread)

I came across this interesting description of grain refinement in Friction-Forging.

-----------------------------
What is Friction Forging® a Knife Blade?
"Friction" Forging® is a localized forging process achieving high, transformation temperatures and high loads against a blade and then employing specialized techniques to achieve a rapid quench. The Friction Forging® is performed on the knife blade in the area that will eventually become the edge. Friction Forging® uses a specially designed tool made from Polycrystalline Cubic Boron Nitride (PCBN), a material second only to diamond in hardness. During forging, the PCBN tool penetrates the blade while rotating, which creates frictional heating. When the tool is fully engaged, it moves along the eventual blade edge, creating dynamic microstructure shearing and the high forging pressures that produce excellent blade microstructures. The speeds, heat and down forces are monitored and controlled by the process computer to ensure the creation of a high-quality blade.
The blade edge is brought up to the transformation temperature by the tool. As the tool moves, the blade material is continuously forged. The combination of thousands of pounds of forging force, tool rotation, and temperatures above the transformation temperature produces dramatic reductions in grain size. The grains are in effect torn apart and reduced in size by the combination of very high pressure and heat. Transmission Electron Micrographs indicate that the grain size is reduced due to Friction Forging from 5 microns in typical heat-treated D2 steel down to 0.5 microns, a superfine "nanograin" size. As the steel is brought up to transformation temperatures while Friction Forging®, the carbides dissolve and go into solution. Because the quench occurs so rapidly, some of the Chromium does not have enough time to reform as a Chromium carbide and is "frozen out" in the ferrite and a stainless zone is created where the Friction Forging® has occurred. This zone is so corrosion resistant that a 10% nitric acid etchant will not etch the processed zone.
The primary benefit of rapid cooling (quenching) is that the higher HRc values are obtained (65 to 68); yet because the grain size is so small and thus tougher and stronger, the brittleness normally observed in steel taken to these high HRc values does not occur. The higher the HRc values, the better the cutting performance and edge longevity-as long as the brittleness issue is managed as it is with Friction Forging®.

http://www.diamondbladeknives.com/frictionForging.aspx

 

[stephanfowler]

T
I UNDERSTAND that there is no physical way to effect the grain structure of steel with a hammer, i get it, really i really really do. i promise.


I don't look back at the knifemakers who USED to claim that hammering could change the grain structure of steel and laugh, I'm HONORED that they would even ATTEMPT to explain the verifiable results that they were demonstrating with their heat treat process. With their limited ability to truly STUDY what was happening, the most correct explanation was that the hammering had something to do with the results...................

NOW, the guys who still to this day claim that hammering has an effect on the grain, wake up, I mean, really, c'mon now.

I'm afraid that the edgepacking was disproved years ago. You simply cannot compact the molecules with the pressures from a hammer. As to breaking up molecules., they are much smaller Much, Much smaller than the grain. It would be impossible to break metal on at molecular level with a hammer. A Nuke could do it.


Mike

I believe you and I agree sir.
Stephan

 

[Tai Goo]

To give science too much emphasis and authority on what is traditionally considered an art form, (such as bladesmithing), really spoils it and takes the fun out. It becomes tasteless and sterile after a while... Keep it up and the day may come when the "best knives" are made by robots.

What happened to romance, mystery, man, fire and hammer?

Science is fine (if kept in perspective), but knifemaking is not a science, nor should it be dictated by science. There are just too many non-scientific subjective intangible aspects, variables and considerations to the art/craft to take any strict scientific approach seriously... There is no genuine scientific approach to any art form,... only pseudoscientific.

You can't use science or logic to prove you make a better knife or the best knife. That's just marketing, promotion and hype.

So is this what bladesmithing and knifemaking have become,... a pseudoscience?

Is this what we want?

Is this where we are all headed?...

I can lump all of the scientific type knifemakers into one group very easily right now... "pseudoscientists".

 

[Keith Montgomery]

I think there should be a mix of science and artistic creativity. A maker needs to have an understanding of the science of knifemaking. I don't think they need to be metallurgists, but they should understand enough about steel and heat treating to be able to do the best work they can. However, someone can know everything there is to know about the science of steel and not be able to make a knife worth a darn. To make interesting and beautiful knives of their own creation, makers have to have an artistic bent.

 

[Tai Goo]

I think there should be a mix of science and artistic creativity. A maker needs to have an understanding of the science of knifemaking. I don't think they need to be metallurgists, but they should understand enough about steel and heat treating to be able to do the best work they can. However, someone can know everything there is to know about the science of steel and not be able to make a knife worth a darn. To make interesting and beautiful knives of their own creation, makers have to have an artistic bent.

I agree!

There are "scientific aspects" to all of the arts.

 

[Lorien]

I totally agree, Tai.

As a former art student/ist, dismayed by the hyperbole and semantic self congratulatory aspects of modern art academia, I quit university after many years to learn the deep, dark art of bicycle mechanics. I am now at the top of my game, melding years of experience fixing things that, to most, are unfixable, with the new school technologies which require study and careful attention to procedure.

Psuedoscience is okay, and probably a good compromise for a knifemaker in general, so long as the maker freely acknowledges that compromise. But as Tai said, for a knifemaker to claim that they are first and foremost scientific in their approach to making knives is for the knifemaker to claim that they are a scientist, more than a knifemaker. Bladesmithing relies too heavily on artistic intent to ever completely fall within the realm of science, as do all creative acts.

Artistic intent can often lead to high performance, while at the same time imparting qualities that fill the knife user with a desire to utilize the tool for its intended purpose. Whether the tool actually gets used, or just lovingly handled, is not really the point. It's about the desire. I trust that a bladesmith who has a reputation for creating high performance knives deserves it, in general.

Science does all it can to remove mystery, desire and romance from everything, leaving sterile logic- kicking Emotion out of its bed after its had its way with it.

 

[David Schott]

I think that once you have developed a style that is desirable enough that people want to buy your knives, you owe it to yourself and your customers to learn the science behind the art in order to add performance value to the style you have developed. Sure, you can make a great performing knife by accident or through a series of accidents (learning process,) but I would always rather know WHY something worked or didn't work so that I could replicate a process or avoid it without being forced to do everything trial and error.

Sure, its a art form....but it has all its performance-roots in science. I think all makers would agree that we'd rather make knives that look shoddy but outcut everything on the market than pretty knives that can't even open letters without having problems. (at least I hope so!)

 

[Tai Goo]

Performance is the "art of cutting".

Performance is subjective,... and there are always compromises and trade offs.

... Have you ever noticed that a clean car seems to run better than a dirty car,... and is more of a pleasure to drive? It's only scientific from a psychological standpoint.

 

[Tai Goo]

I think that once you have developed a style that is desirable enough that people want to buy your knives, you owe it to yourself and your customers to learn the science behind the art in order to add performance value to the style you have developed. Sure, you can make a great performing knife by accident or through a series of accidents (learning process,) but I would always rather know WHY something worked or didn't work so that I could replicate a process or avoid it without being forced to do everything trial and error.

Sure, its a art form....but it has all its performance-roots in science. I think all makers would agree that we'd rather make knives that look shoddy but outcut everything on the market than pretty knives that can't even open letters without having problems. (at least I hope so!)

Yes, it's all an ongoing study. And there is always room for learning and improvement. However, if you understand the "process" and can make a consistently good knife,... it's not an accident. You don't even need to know the science to understand the process, and can explain the process scientifically or unscientifically... just like baking a pie.

A great painter doesn't need to know the chemistry of the paints (outside of basic compatibility. Oil and water don't mix, obviously), or even anything about color theory. It can be done instinctively and intuitively.

There are also many great musicians who don't know squat about music theory. They do it all by ear.
They don't need to know the metallurgy behind their piano strings to play... That's ridicules!

"Concept" dictates art, and we don't all have to work with the same concept or concepts of performance or aesthetics. Depending on the concept, performance may play a greater or lesser role... there is no right or wrong to that.

 

[tvandeventer]

When is "pseudoscience" ever acceptable or okay? It means "false or fake science". Even being called a pseudoscientist should be taken as insulting, especially if the person offended is indeed, a real scientist. Pseudoscience has no place and should always be discouraged.

In fact, packing the edge and manipulating crystyline structure with a hand hammer simply falls withing the realm of "common knowledge" among the smiths of old. Several professional slaughter house butchers in the hills of eastern Tennessee concured when it was said that placing a sharp knife in the light of a full moon will dull it. Others say that a blade placed under a pyramid will sharpen it. What happens if you put a blade under a pyramid in the full moonlight???!!! But I don't think that there are a lot of knife makers out there these days who really believe the old stuff. A few but not many. And there are a few hucksters in every walk of life.

People who are interested in making good knives are interested in testing and research, if for no other than to make one for their own use. How many times have you heard, "I started making my own knives when I could not find a commercial blade that I was happy with."? Since most of my cohorts happen to be ABS guys, I can only base my observations on this faction of the industry. ABS makers are brought up through the ranks being taught to test blades. Most have continued this practice as part of their quality control. Can't speak for the rest of the community but I think we all in one way or another want the perfect blade, who's shadow will shave hair and never needs sharpened. Hats off to the guys who try to take it even further. We all learn from them.

Cheers,

Terry Vandeventer

 

[Tai Goo]

The best way to avoid being called a pseudoscientist is,... not to profess to be a scientist in the first place...

I am not a scientist.

I am a bladesmith,... a student and practitioner of the "art of cutting", and the "art of cutlery".

I use science, but science will only get me so far.

Art transcends science.