Better quality knife, forging or stock removal

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Just as an aside, I asked my primal buddies about the origin "edge packing". Turns out it was a technique used ages ago when blades were made of wrought iron. Apparently it's basically a type of work hardening that only works with wrought iron. Anyone here still use wrought iron for blades? ;) It probably keeps resurfacing due to people either getting half-information or reading outdated texts on bladesmithing. Anyway, just thought I'd pass that along.

Tim
 
In the old days ,and still today, you sharpen a scythe or sickle two ways ; you can use a stone or you can work harden the edge. The work hardening is done cold (cold working)with a hammer and small anvil which you stick the sharp end into a stump.A search on 'scythes' will get you a source for these anvils. Of course the steels are fairly soft. ......Having seen the crowds at blacksmithing demonstrations at renaissence fairs etc there is obviously something fascinating to people of all ages to see the smith 'play with fire and hit stuff with a hammer.
 
Ok, you guys have pounded the "edge packing" argument to dust...

But, what about the "grain of the steel" argument?


(as it has been explained to me: )

On a forged knife, you can pretty much keep the "grain" running straight from bolster to tip, regardless of the shape, curves, bends, etc. This is why you "pinch-form" the end of your bar when making the tip, etc.

On a stock removal knife, 9 times out of 10, the "grain" of the steel does not run directly to the tip. Worse yet if there is a bend or a curve.


Fact or fiction?
 
Originally posted by pendentive
Ok, you guys have pounded the "edge packing" argument to dust...

But, what about the "grain of the steel" argument?


(as it has been explained to me: )

On a forged knife, you can pretty much keep the "grain" running straight from bolster to tip, regardless of the shape, curves, bends, etc. This is why you "pinch-form" the end of your bar when making the tip, etc.

On a stock removal knife, 9 times out of 10, the "grain" of the steel does not run directly to the tip. Worse yet if there is a bend or a curve.


Fact or fiction?
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OK, what happens on a pattern welded or damascus blade?

Craig
 
Originally posted by C L Wilkins
OK, what happens on a pattern welded or damascus blade?
Click to expand...
Yes, an answer to that would be nice too...
 
We covered this one quite a bit in another thread; I think it was the one dealing with triple quenching. Remember I said that hot rolling the as-cast ingots helps to close up voids, porosity and inclusions? Well then these single point defects get drawn out with the surrounding steel they form long lines in the steel that will give it a “wood grain” like appearance (the inclusions will form the nasty stringers that we encounter form time to time). This fibrous texture or “flow lines” are NOT to be confused with the austenite grains. The flow lines will remain throughout the heat-treating process because they physical defects and cannot be affected by diffusional processes. If you take a sheet of steel and shear a strip off it, with the flow lines running the length of the steel, you can see how the toughness of this strip will be greater than one sheared perpendicular to the flow lines. In things like crank shafts (which is the most common example used in metallurgy) great benefits can be gained from forging things to shape and not cutting across the flow lines.

But with a knife blade, as long as the flow lines are parallel to the length, how much benefit is there to be gained from it? A few lines will run off the tip of the blade if it is ground, will this manifest itself much in performance? Not likely.

All of this is completely independent of austenite grain structure, which can have profound influences on strength and toughness. Austenite grains can be affected by deformation and by heat, with heat having the greater influence. One may be able to induce changes in austenite grain by working the steel, but all previous affects will be undone and reformed as soon as one approaches Ac1 (the heat at which recrystalization begins). The only way to maintain the affects of hammering is to do all of it via cold working and never heat treat the results. The simple facts are that if somebody is telling you that they make a better blade because they “align” austenite grain at the edge, they are either ignorant of the basics of the behavior of their medium, or they are flat out lying to sell something. You can do a few things to make grain finer, but not maintain “alignment”.

Damascus poses many questions in metallurgy. This one is one of those exceptions. Which way the pattern flows can have some affects on cutting action and how it degrades and quite possibly an influence on directional impact strength and other factors. All of this would be massively influenced by the alloys used in the mix, of course.
 
Ok, so flow lines do matter, in terms of overall toughness.

But what about at the cutting edge itself?

I'm thinking mostly of a recurve, khukuri-type blade which if it was cut out of a steel bar, would have the "grain" running nearly perpendicular to the edge at the "sweet spot".

Does it matter?
 
The inclusions are the problem , "dirty steel" with a high amount of inclusions will have more "grain" than clean. So how do they make the steel ? If you look at something like BG 42 you will see that it is originally a bearing steel and is double vacuum melted , that's CLEAN . ....BTW Kevin didn't answer a previus question of mine . What happens to the oxides and flux in between the layers of damascus ?
 
Originally posted by XRAYED
Dan....make sure you bring a video camera....I am currently hunting for Bigfoot.
Click to expand...

stop hunting Greg he's been out in back of my place for the last
2 years.:D :D and Nessie is on Vacation in the dead Sea..:)

Thanks Mete and Kevin and the rest of you..
we need this stuff out on the table
if we are too truly make the best knife possible..
Quoted By many a Maker..

This thread is so Cool
I'm posting it on the knife making site.
under
forging or stock removal, Best quality knife?
Is Edge packing is a myth??
edited to add
see http://www.cashenblades.com/articles/lowdown/lowdown.html
:)
 
Originally posted by mete
Dan, maybe put stuff under the heading "Knife Making Myths"
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it's under
the Interesting Information section right now as..

forging or stock removal, Best quality knife?
Is Edge packing is a myth??

if I get enough of that stuff and can keep up with it
I may dedicate a page for it..

Myths in Knife Making :)

if Kevin wants to separate what he has from this thread
and you the same together or separate I'd be glad to
put them on a Page of their own. but right now the link points to this thread.:)
 
Originally posted by mete
The inclusions are the problem , "dirty steel" with a high amount of inclusions will have more "grain" than clean. So how do they make the steel ? If you look at something like BG 42 you will see that it is originally a bearing steel and is double vacuum melted , that's CLEAN . ....BTW Kevin didn't answer a previus question of mine . What happens to the oxides and flux in between the layers of damascus ?
Click to expand...

I'm sorry, I assumed it was a rhetorical question so I was actually waiting for you to give the answer. As for the possible affects of residual boron from the flux, I have not done enough study into that area to make any safe statements about it, so unlike too many other bladesmiths I must plead ignorance so as not to disseminate bad information by making assumptions or conclusions.

The fact that oxides and fluxes are present at the weld zones is fairly self evident. The borax seems to result in a lighter colored weld seam. It does appear to have an affect on how the edge cuts and wears as it cuts. This is another reason why it is so hard to come up with concrete conclusions about the behavior of pattern welded. There are just too many variables. Are we changing it's behavior by the contaminates we add in the welding process? I have a lot more testing aheadf to determine much of this.
 
As far as the knife as a crowbar is concerned, I generaly am not interested. In my particular case craftsmanship often concerns finding ways to align force with the edge rather than across it. Such are the myths of woodwork.

I thoughtt he point of the bendible knife was that you could have a harder edge than would be practical in an all say 62RC knife, since such an object would be too prone to cracking or something. At least that is somewhat the purpose in the Japanese product.

I do agree however that it is at times something that one can have that may or not be particularly useful.
 
This is a messy debate however you look at it. Everyone believes in the method they use.

All I can say is that at a minimum, forging allows you to do a lot with a little. You can get an entire blade out of a few inches of 3/4" round stock.

BTW, if there have been any threads on forging CPM steels, could someone point them out to me. Thanks! (I'll try searching too, but nothing ever seems to turn up when I try to search for it)
 
I can't believe I could ever inspire such a debate, this is great! I've read the whole thing twice. The first time I crusied right through it and the second with a dictionary. I learned a bunch.

From what I gather from this thread, the highest quality blade is one that allows its maker to have the most fun. The best performing blade is accomplished by negotiating the heat/material relationship in a way that will perform most affectively for its particular application.

When I start forging blades, I won't "pack" the edge. Which brings me to a question I asked a few dozen replies ago... I need to know more about medalurgy and bladesmithing, is there a good book or books for this?
 
I wish I could say yes, but to be perfectly honest, I haven't really liked the books I've purchased. They're either too dumbed down, or way over my head.

The best learning experience I've had to date was on a cold October morning having Larry Harley yell at me while I hammered the @#%#$ hot steel..."You're going to hell"..."Swing it at your d*ck"..."C'mon, hit that thing with authority!"...

:eek:


Good 'ole Harley...;)


Seriously, attending a hammer-in or visiting another blacksmiths/bladesmiths' shop is priceless for the beginner...
 
Originally posted by mattd
...From what I gather from this thread, the highest quality blade is one that allows its maker to have the most fun.
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There is more thruth in this than what many people know. Blades that enjoyeable and fun to do always come out better than the ones that you have to force yourself to work on.

Which brings me to a question I asked a few dozen replies ago... I need to know more about medalurgy and bladesmithing, is there a good book or books for this?
Click to expand...

Many have found "Metallurgy fundimentals" by Daniel Brandt to be a good introduction. "The Heat Treaters Guide" by ASM, will be quite expesive to purchase, but if you can barrow, from a library or a friend, it is full of most of the information that you need to heat treat. "Introduction to Physical Metallurgy" by Avner is an excellent book for much of what we have been talking about here. Unfortunately some of th worst information will be found in publications dealing specifically with knives and bladesmithing, though there are some exceptions. Magazines have a nasty tendancy to print anything without verifing if it is nonsense or not.
 
Tim,

I am the one that brought up balance differences in the other thread.

I tried to be clear that I was not necessarily attributing the difference in Balance to the process but I still maintain that there tends to be a difference.

I still don't know if the difference is because it is easier for a Smith to achieve balance while forging or if it is because Smith's are more focussed on balance.

Scott
 
I understand the "balance" thing better now. I think what you are noticing, at least this is what I have observed, is with high production grinders and those who haven't got quite as many under their belt yet, there is a tendancy to buy the steel in flat stock and just grind the edge on. This results in a blade that is 1/4" at the guard, and does not taper but remains 1/4" until a short distance form the tip where it is suddenly reduced to t poit by the edge grinds converging. I completely agree that bldes that are cut from flat stock and have just an edge ground on will be "heavy" in an uncomfortable way. But really good grinders will understand this and will grind a taper in and balance the blade out very well.

In fact, on larger blades I rarely do much balancing or tapering on the anvil, I will save this "fine tuning" for the grinder where I have much tigher control. I think your hunch is right that forgers force themselves to be more conscious of balance and that is the reason that it seems more prevalent in their blades.
 
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