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OutofGum
02-06-2005, 11:30 PM
Is there any? In the world of kitchen knives forged blades are considered superior to stamped ones. Almost all high end knives are forged. I know that for the most part, stainless steel can't be forged (I think one guy does it), but in the world of non-stainless steel, is there an advantage in having a forged blade?

JD Spydo
02-07-2005, 07:07 AM
When I had the pleasure/privaledge of meeting Bill Moran in person at the 2002 Atlanta BLADE Show I asked him that question. He told me that the forging actually increases the density of the blade steel. I have personally noticed that the forged knives I have really hold an edge well. That may not be true for all forged knives because I am sure the actually type of blade steel plays a huge role in that. You can certainly tell a difference when you pick up a forged knife. The weight difference is very obvious to me anymore. ;) :spyder: :)

OutofGum
02-07-2005, 10:52 AM
That makes a lot of sense. I never realized that before, but now that you mention it, it seems very clear. There was always a feeling of quality from a forged blade, but I couldn't put my finger on exactly what it was. Thanks!

spyderknut
02-07-2005, 12:29 PM
I have read that steel density change with forging is a myth. I think the weight difference you feel between a forged and stamped kitchen knife is the amount of steel and maybe more attention to balance on a higher quality blade. I think the forging process does align crystals and that is the main reason for performance difference.

Jimd
02-07-2005, 02:13 PM
I enjoy owning/using handmade knives. Just something about it being "handmade" that I like.

Currently, I don't own any blades that have been forged. All my handmades right now were made using the stock-removal method, ie., beginning with a bar of steel and grinding away everything that's not a knife.

thombrogan
02-07-2005, 04:48 PM
The density changing thing ("edge packing") may have been true 300 years ago, but not since steel-making techniques have improved. The only thing that seems to be better about forged knives is that their makers tend to have more fun beating stuff with hammers than they or the stock-remover folks have when using a belt-grinder or hollow-grinder.

fret
02-07-2005, 04:48 PM
I have some old kitchen knives, butcher knives and paring knives my Grandparents had, that are carbon steel and hand forged. I can get them razor sharp and they hold an edge great. They will rust just laying on the counter top tho. Not dishwasher safe either. But they do get extremely sharp and stay that way. ;)

thombrogan
02-07-2005, 06:46 PM
But is that from their forging or from having a good steel? :confused:

OutofGum
02-07-2005, 08:28 PM
The expensive knives are definitely more weighty than the cheaper stamped knives, but the steel is of similar thickness. I the metal is more dense. The knives also feel different when slicing - even after they have both been sharpened. Maybe its the ergos.

JD Spydo
02-07-2005, 09:47 PM
I don't see how anyone can say that forging a knife does not make it more dense. I on several occasions had both forged and regular just cut out of stock type knives and there is definitely a weight difference in the forged ones. The blade steel that even has pretty much the same physical dimensions is noticably heavier. Considerably heavier to the point that you don't need a scale to prove it either. If forging does not increase the density or improve the properties of the blade steel then the custom knife makers wouldn't even fool with the extra work. Plus the man that told me that I give a great amount of credibility to. But obviously some don't agree me. But we can respectfully disagree and I do on this point. :) :spyder:

CutEngineer
02-07-2005, 10:42 PM
I used Google and looked up 'forging faq'. The most informative that I spent the time to look at is given here. (http://www.rsrfasteners.co.uk/rsrforgings/rsrfaq.htm#two)

Apparently, the biggest advantage now is to improve the 'grain flow' of the metal. I can see how this might improve blade strength in knives, but I don't know how this applies to edge holding.

spyderknut
02-07-2005, 10:57 PM
Here's what I found on google:
http://www.newwestknifeworks.com/answer.shtml
Blade magazine had an artice a few months ago that explained this pretty well IIRC.

dialex
02-07-2005, 11:46 PM
From what I know, steel is a mixture of cristallin molecules, of different sizes. Normally, they are arranged more or less evenly in the material. Heating and then rapidly cooling the metal makes it harder, because this way, bigger crystals are formed.

By forging, the crystals are rearranged. The bigger ones are pushed towards the edge, while the small ones stay in the middle of the blade. A good forged blade will have big crystals on the edge (therefore the edge will be tough) and the middle of the blade will have smaller crystals (therefore the flexibility).

Obviously, larger blade benefit more from forging than smaller ones. IMHO, forging a 2" blade won't add much to its functionality.

JD Spydo
02-08-2005, 06:52 AM
To "CutEngineer" & "Spyderknut". Can you guys tell me your sources. I am home all day and I am going to research this more. First of all "CutEngineer" can you give me your website/reference for your info. Say "Spyderknut" can you tell me which issue of BLADE you found that in. I have every issue going back to 97. I would like more precise info on it. Now for everybody concerned. Mr. Moran did tell me that about the "grain" just like CutEngineer mentioned. I will admit I am no bonafide metallurgist but I have read tons of stuff out of these knife magazines over the years and now I would like to get the straight scoop on it. I have all day so lets all get to the bottom of this. I welcome anyone else's input as well. PEACE brothers. Now let's find out. :)

CutEngineer
02-08-2005, 07:03 AM
The word 'here' in the message above is the link. Here it is again.

http://www.rsrfasteners.co.uk/rsrforgings/rsrfaq.htm#two

thombrogan
02-08-2005, 07:52 PM
I don't see how anyone can say that forging a knife does not make it more dense.

Unless the steel is riddled with hollows and inclusions, it will have the same density as non-forged steel which has received the same heat treatment. The iron, carbon, and alloying elements will arrange into a finite amount of crystals and the crystal size (i.e. density) will be the same whether a hammer smeared the metal into place or a stone wheel hogged off all of the non-knife steel.


I on several occasions had both forged and regular just cut out of stock type knives and there is definitely a weight difference in the forged ones. The blade steel that even has pretty much the same physical dimensions is noticably heavier. Considerably heavier to the point that you don't need a scale to prove it either.

Are you saying that the steel of both filled the exact same volume? That's a hard one to eyeball. Also, since balance effects perceived weight, a scale would be a better judge (it takes more force to open a door at its hinges than at its doorknob side, but the door weighs the same). Ironically, in the sword world, buyers look for the lighter sword.



If forging does not increase the density or improve the properties of the blade steel then the custom knife makers wouldn't even fool with the extra work. Plus the man that told me that I give a great amount of credibility to.

That's not true. The blacksmith/swordsmith/knifemaker who explained why edgepacking is a myth loves banging molten steel with a hammer. The other smiths who forge tend to hand their time at the grinder and love their time at the hammer or the power hammer. Also, while no measurable performance improvements may be found from forging, one can fashion tools and fittings which cannot be made with a bandsaw and grinders (unless you're insanely skilled).

Did the man who told you about edge-packing/density explain how it occurred or was his say so good enough? I know a guy who has more talent after being bitten by a rattler than I'll ever have in my most lucid moments and he's incorrect when he says forging makes steel more dense at the edge.



By forging, the crystals are rearranged. The bigger ones are pushed towards the edge, while the small ones stay in the middle of the blade. A good forged blade will have big crystals on the edge (therefore the edge will be tough) and the middle of the blade will have smaller crystals (therefore the flexibility).

The smaller martensite crystals are the harder ones and the smaller pearlite crystals are the tougher ones. Even there, highly-tempered martensite can be insanely tough, especially it forms in lathe-shaped crystals instead of plate-shaped crystals. Flexibility may be enhanced through having certain types of crystals, but it's mostly a function of blade thinness. The hammering can rearrange the crystal size, but most of that is achieved through heat-treating versus hammering.

JD Spydo
02-08-2005, 10:36 PM
The following is right out of one of my Metallurgy textbooks I have from when I took a metallurgy course in college in the Machine Tool program that I trained for. It says this: "Forging is the process of working metal to the desired shape by impact or pressure. The process is formed using hammers, upsetters, presses, rolls, and related equipment. The principal advantage of forging is that it orients the grain flow to the contour of the component. This often provides the highest strength in the direction of greatest stress. The higher strength-to-weight ratio achieved results in the use of smaller or lighter components." end of text. ---- That was not my words about the subject of "Forging". It was out of the college Textbook entitled "METALLURGY" 3rd edition B.J. Moniz ISBN#0-8269-3512-5. This is a very respected college textbook and it was a textbook used in 3 of my classes. It evidently indicates that there is a beneficial result of Forging. Although it did not make any mention of density but it does reinforce the fact that forging does have positive attributes and it is not done in vain. I rest my case. PEACE and thank you all. :)

Jimd
02-09-2005, 02:09 PM
Some say that forging has definite advantages, and have backed it up with publications sources.

Others say it's worthless.

Personally, I don't care. If I ever see a forged knife that I really like, and I can reasonably afford to buy it, I will. Will I buy it because the molecules are aligned, etc.? It's a neat concept. But most likely I'll buy it because I like it a lot, and it was hammered into shape by a person's skill. Such knives are artwork in the form of the tool that they are.

And that's good enough for me.

thombrogan
02-09-2005, 07:13 PM
Good book, JD Spydo!

Great point about forging, too. With steels used for knifemaking, the flat plates leave the steel mills with the grain already going lengthwise (or cross-rolled for some of the newer powder steels such as S30V). So the advantage would go to forging if you were comparing forging a knife from a giant ball-bearing versus stock-removing a blade from the same bearing.

You'll find that even if the edge could be packed during forging (big if, there!), the subsequent heating, quenching, and tempering would unpack it, especially if multiple normalizing cycles were used to control grain growth.

Otherwise, I think that what you're finding is a larger pool of skilled blacksmiths than you are stock-removers.

Jim,

That's the best reason to choose a forged blade that I've seen.

JD Spydo
02-09-2005, 09:16 PM
well Thombrogan I am glad I am getting closer to what I need to learn. The book that I mentioned is truly one of the most decent textbooks I have ever come across. The book is an unbelievable source of info for exotic metals and non-ferrous metals as well. You make a great point by the fact that a lot of things you learn by actually being in the shop and actually doing it is info that hardly ever makes it into college textbooks. You know it really makes me wonder if Nickola Tesla would have ever liked Spydercos or knife making.
That's what I am loving about this Forum. There is just so much out there if you look for it. If they have this textbook in your local library you would like thumbing through it. With all of the new innovations with Cera-Titan, Ceramic, titanium alloys and such it just makes one wonder what they will be making blades from 50 years from now. :spyder: :spyder: :)

thombrogan
02-10-2005, 05:32 AM
That book is at my bedside as I type.

You've read more of it than I have.

If you want to hang out where a lot of smiths and metallurgists yuck it up, go over to SFI (http://forums.swordforum.com). I don't have the URL handy, but a ton also go to Don Fogg's forum, including Ed Schempp.

The University of Cambridge (http://www.msm.cam.ac.uk/phase-trans/) has a lot of great resources on metallurgy, too, including a free (http://www.msm.cam.ac.uk/phase-trans/newbainite.html) online book about bainite.

JD Spydo
02-10-2005, 06:39 AM
Say Thombrogan you got my curiousity going. We have a School/College here in Missouri that is supposed to be the one of the very best in the US ( according to them I guess). It is called the University of Missouri at Rolla/school of Mining & Metallurgy. My nephew who is truly the genius of the family has taught Calculus at that University. He told me that people from literally all over the world go through great pains to get into that school. I am just curious if you have heard of them or not? I met a guy who had a Master's Degree from that school who only graduated with a C average and told me he was glad to get that. He seemed like a pretty bright guy too. I have always heard how academically aclaimed they are. Have you heard of them? :spyder: :spyder:

dialex
02-10-2005, 03:26 PM
Thanks for the corrections. Looks like I knew lots of distorted facts (not that it would be for the first time) :(

thombrogan
02-10-2005, 05:25 PM
Looks like I knew lots of distorted facts

If what I believe to be true turns out to be a pack of lies, it wouldn't be the 9000th time.

JD Spydo,

I know of that university because of computer programming. Scott Mitchell (http://www.4guysfromrolla.com) is an author of computer books whose claim to fame is graduating from University of Missouri Rolla (that and being very helpful and smart). Something/somewhere new for me to check out. Thanks!

turebrand
02-10-2005, 06:11 PM
This a little of what I know of the subject.

Forging , or deformation of steel, will at first lead to a slight increase in grain size but when you reach the point of critical deformation, or to be precise go beyond it, the larger grains will dissolve into a smaller, more desirable grain size.

Everything is controlled by energy, if left at a high temperature, the steel will strive to lower the internal energy (surface energy) by growing larger grains, by introducing enough deformation, you not only break up the larger grain structure but also introduce the energy to form new smaller grains.


And it should only be done at the proper temperature, or else (as someone stated earlier) youīre likely to introduce tension and cracks in the material (too cold) or grain growth (too hot)

All steel is basically forged (between rollers) when manufactured.

I do think that forging a blade is a skill well worth preserving, if not for performance, then for nostalgic reasons. Thatīs where steel working came from :)

/Anders

thombrogan
02-12-2005, 12:50 PM
I do think that forging a blade is a skill well worth preserving, if not for performance, then for nostalgic reasons. Thatīs where steel working came from

Great points, Anders.

There are scholar/swordsmiths trying to resurrect wootz steel for European and American audiences. There's still plenty of info available to our Farsi-speaking friends, but info in other languages is few and far between. From what I've read, wootz is a hand-forged steel which can live up to its hype (though that's still entirely dependent on the smith's skill).