Forged/not forged (only grounded) blades?

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pig

Joined
Mar 12, 2003
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Hi blade makers,
I did post this topic (below) to the question forum.
I was surprised about the few numbers of replies (thanks to Rick the only one).
Discussion about problems with alcohol (an example) was more popular in this forum (by the way I have also used alcohol time to time too much, and it is an important topic, but....).
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My hobby is knife making and I forge my blades, but:

There are two opinions.

(1)The classical one is that reduction of thickness (50-80%) by forging is good to fracture the crystalline structure tighter, making much better blade.

(2)A new argument (not mine) is that current new steels (as O-1 for example)are so good (content and handling in factory) that forging do not help essentially as it did in the past.

Have anybody anything concrete about that, not just belief or wish?
Have you seen any published reports of metallurgy?
Have you experimented by yourself?

It would be easy to work the same steel two ways (into same dimensions) and heat threat both similarly and compare blades at work.
Anybody done already?

Good blades! Tuomo
 
dude , im not an expert, nor do i understand what you are asking.

maybe you should repost this in the shop talk area, or maybe a moderator will move this one.


Grinding to make a blade can be done, instead of forging. Its what i have been doing to make my first knife, what i did was get a piece of steel (call it stock) then i cut it into a general shape and then i filed the rest by hand, you can use a grinder, sander whatever. It is a method called stock removal.
 
Tuomo, write about this in shop talk forum -you'll find more makers and answers there.

A bit in Finnish: Muutamat täälläkin kirjoittavat veitsentekijät tekevät molemmilla tavoilla- takoen ja hioen. Monet sanovat saavansa paremmat terät takoen - Ed Fowler jne. Takoja kun itsekin olet tiedät, että takoen terät muokkaava ei ole rajouttunut vakiokokoihin teräsaihion rajoittaessa muotoja...
Takoen saadaan edelleenkin vaikutusta terän teräsmatriisiin ja karbidien jakautumiseen teräalueella - aikaisemmin takomisen etuna oli (ehkä erityisesti) se, että teräkset olivat huokoisempia kuin nykyään ja takoen huokosista päästiin eroon. Luonnollisesti takojan on edelleenkin mahdollista tehdä osittainen lämpökäsittely luontevammin kuin hiojan. Itse en tao teriä (hioskentelen rostereita muotoonsa) - viittaan vain lukemaani aineistoon.
 
I'm not much at reading Finish, but it looks good?
Years ago Wayne Goddard and I compared forged vs stock removal blades from the same 5160 steel. the forged blade out performed the stock removal. The results are discussed in my book Knife Talk available through Krause or me.

The combination of knowledgable forging, thermal cycles and well considered heat treat is hard to beat. There is much the stockremoval man can do to achieve excellent knives, probably as good or better than a lot of poorly forged blades.

Dedication to the experimental method, and desire are hard to beat in either venue.
 
Hallo! This is my first post to this forum...so be gentle with me. In response to your question re: forging vs NOT.
Well Bubba, I'm in the process of working through that one myself. Using 5160 as a test medium. I have a number of blanks made from quarter inch by one inch stock. I have forged a tang on each test model. I will basically be repeating the Fowler/Goddared test published in "Knife Talk" I want to see the difference between single, double and triple quenches in 5160 steel. E-mail me and I'll keep you informed as to the results.
 
Welcome aborad Shane: Your views and results will bring more knowledge to the forms.
 
Hi Shane and Ed,
nice to see this discussion continues.
I conducted few tests myself.
I did take 5 blades.

a) Stock removal Swedish Mora "carpenter knife" (puukko)
b) Stock removal similar stainless knife (very cheap)
c) My own test blade only grinded/edge tempered to dark yellow/brownish
d) My forged test blade (edge packing used)/ edge tempered to dark yellow/brownish
e) My old own forged blade, edge tempered pale yellow

Material of my knifes near American O-1,a German cold tool steel (Bohler K460).

Profile angle and sharpening the same (profile 17 degrees, best for wood).

Test:
Dulling: draws across a round copper bar until not cutting any more arm chair. A weight of about 2 pounds on top of the knife with pliers during draws. (I started first by sharpening 2x4 inch pine boards, it was too slow and painful to get knifes dull! I sharpened quite a pile of boards.)

Results, number of draws:
a) 2 times
b) 2 times
------------
c) 10 times
d) 30 times
------------
e) 80 times

This single test suggest that forged is 3 times better and tempering really matters.
(I think that the steel used is higly "karbide forming" and this maybe gives extra benefit with "metal, copper, based dulling test".)

Now I am starting tensile strenght testing.
My preliminary tests did not show advatage of
forging on the tensile streght.
(Also I was surprised how good a test blade from
an old carbon steel file was as to toughness.
I believed that high carbon content makes the knife crack easily on tip. Right tempering seems to sove the problem.)

I am very interested to hear about test of others!
Please, send me e-mail also directly if not too difficult.


Pig from Finland
 
pig,

I've had 2 or 3 classes in metallurgy while getting an engineering degree, but don't have actual black-smith type experience. So from a book/class point of view, forging should improve most of the characteristics of just about any type of steel vs grinding (material removal). The differences will really become evident when you shift to swords vs knives. In general, forging will align the grain structure so that the stress lines flow smoothly within the object shape lessening the chance for failure of the object when subjected to severe stress. Hardness on the other hand is more a function of quenching and material characteristics than forging related. To avoid having too brittle of a sword/knife, the blade is often tempered to relieve some of the stresses induced by quenching, hopefully with little or no loss of hardness. A flat forged bar that is then ground down to an edge should already most of the needed grain alignment in it, so that it should perform satisfactorily. Forging the edge would improve these properties even more, but the % of improvement would be smaller than the initial mfg.'s forging of the bar.
 
I have Ed's book (it is a good one for knife nuts the world over!) and I read the article about forging vs. stock removal. One thing I'd like to say abou that is Wayne and Ed took 5160 years ago and worked on it. I wonder what results would arise if some super steels from Crucible were used (the particle metallurgy styff), or some high tech stainlesses, like S30V or Cowry-X. I believe that forging some materials definitely will make a better knife than a stock removal, but this will depend on the material one starts with.
 
Hey Ed ! Thanks for the encouragement!

For all the folks reading this thread I'd like to read a bit from the book of Fowler! Could we all take a knee as I read from the good book!

The elements we seek when pursuing high performance steel are sometimes contrary to one another.Hardness would seem to be of primary importance. But a blade too hard will be brittle. And it will be less "machineable", that is, harder to sharpen. Which, for a lot of customers is a down point.

Because of these seeming contradictions the smith must become extremely aware of the tolerance ranges of his particular medium.
And when he decides to test his product, he must do so with the idea that he may have to temper an extra cycle to decrease hardness while at the same time making his blade less likely to snap when pressure is applied to the blade during general use. Anybody who has used a Buck knife on big game will give me an Amen on that!

So to Pig I say,testing IS the way to go. However if you are to determine the qualities of forged vs NOT. You must test like subjects. Apples to apples.

My own test will look something like this.
* denotes quench in Texaco Type A
All hardening is done with a oxy/acetyl torch, #3 victor tip and a 3X flame. Differentially edge hardedned.
All stock will begin as one quarter inch by one inch.
---------------------------------------------------------------------
1 5160 blank~stock removal~normalize~ hardened ~single quench*
triple temper at 350 degrees F.
1 5160 blank~stock removal~normalize~ hardenend with double quench*
triple temper at 350 degrees F
1 5160 blank~stock removal~normalized~ hardened with triple quench*
--------------------------------------------------------------------
1 5160 blank~forged to shape~normalized ~hardened with single quench
triple tempered at 350 degrees F
1 5160 blank~forged to shape~normalized ~ hardened with double quench
triple tempered at 350 degrees F
1 5160 blank~forged to shape~ normalized ~ hardened with triple quench
triple temper at 350 degrees F.
---------------------------------------------------------------------
Just for fun:
1 5160 blank~forged to shape~normalized ~ hardened with water!?!

Testing:
1.) Test for hardness with a new single cut nicholson file.Approx Rc Hardness will be noted. Best guess since I don't have a RC tester.
2.) The dreaded brass rod flex test. I'll look at edge toughness in each test subject. # of flexes without chip.
3.) Rope cuts. I'll a single lay from a 3/4 inch oiled manila rope.
4.) The ninety degree flex test. I'll be able to see if the flex happens evenly along the blade...or if it creases.

Now, before anybody has a cow. When I forge blades for sale I use multiple normalzing and the bladesmith's anneal, as well as multi quench,multi-temper and cryo cycles at -20. This series of test was just for me. In my own mind I wanted to be able to prove to myself that I had paid my dues. So I am following this process to the strictest letter possible. All the steel is from the same bar. Each blade will be handled in the same fashion. As much as is humanly possibe there will be no variances.

A final note about testing. We have to keep ourselves honest by reporting what happens. NO cheats are acceptable.

Ok, Ed did I miss any of the obvious stuff?

Hey Crayola! You brought up a good point! Why dont you get some of those modern steels...run the same tests and we can release our results right here in living color! The gaunlet has been offered! LOL!

Whoop! There it is!
Out for now!
shane
P.S. For all of you guys who are struggling to make your first blades, READ Ed's book! I don't meant scan it. Read it! Pay attention to the work he has already done in this area. There is no testing I can do that Ed hasn't already done. Believe me! Ed will get you through that ABS test and beyond! Forge from thick stock at low temps!
Keep the faith!
 
Scotjute; Yes all steel is forged, some exceptions ie. liquid stuff and the like. How and at what temp it is forged at is significant to grain refinement. If forging is done above 1750f grain alingment happens, but grain refinement is not as great as if it were forged below 1750f because grain grows at temperatues over 1750.This is the advantage the bladesmith can provide the steel if he does everything right. I keep forging temperatures 1625 and below. It is easy to tell when you are at this temperature as the slag that forms is fine, like snow flakes. You are too hot when the slag comes of in sheets. 1625f is a safe temperature and provides a 125 degree safety zone.
I recomend starting forging with the largest stock you can handle, the greater the reduction by forging the greater the potential performance qualities of the resultant blade.

Shane: your experiment looks good, enjoy your voyage and I am looking forward to seeing your results.
 
Shane talks sense,
imortant things about testing and books.
Books are really only help for most smiths without a mentor (in addition to own experiences).

I would add few comments and things.

Testing stock removal blades against hand made is an other imoportant issue but still quite different thing that testing strictly forged/grinded difference!

In my simple test in my last post I got
a big difference between MY GRINDED and STOCK REMOVAL GRINDED (bulk quality). We do not mostly know about the steel and tempering of stock removals. They must compromise between edge holding and toughness. Black smith can temper edge and spine and tip differently.
The big difference I got was mostly, I suppose, due to different tempering.

To really test the effect of JUST FORGING we must by ourselves make both type same dimension and same tempering knifes from the same material.

I tested only edge holding in a single test.I contonue with other things.

One matter is that only edge holding is the area where stock removals can even try to compete. I suppose the best new steel high class stock removals are far behind as to the power neeeded to crack the knife by bending, if hand made knife is tempered "spine blue".

There is also discussion about toughness got leaving spine unhardened as an option to separate spine temepering.

I found that the power needed to bend unhardened spine knife is much more than ten times less than the power needed to bend "blue tempered spine knife"!
(Well, if we have unhardened spine and pale yellow edge, all is weak- spine bends and stays bent and edge cracks.)
By the way, is this mentioned in any book?

I really hope that even more smiths start doing experiments and report about results.


Let's continue Shane and many others: pig
 
Guys,we are onto something here! Let's pay attention to this
discussion.
But first let me say that books are not just for people without mentors. In fact, even when I was in apprenitceship I read voraciously from any book I could get on blades,steel, soldering welding,metallurgy and all other written information regarding metals. I also studied other subjects, such as art ands design. And lastly, I have studied philosophy with many of ther great minds of our planet, Thoreau, Twain, Whitman, Sun Tzu, Loa Tzu, Miyamoto Musashi and many others. I can't help but think that each and every one of them has in some way been my mentor.I would do each of them a disservice if I claimed all of the information that has helped me to this point was completely my own.

In Ed's case... he was my mentor years before we ever met. In the pages of Blade magazine, and later in Knife Talk, Ed talked me through the processes of forging a blade. He never told me to do it his way, he only offered guidance. Many years later, when Ed and I finally looked each other in the eye, it was if I already knew him.

Next,it seems that you and I are folloowing the same path. With slightly varying points of view. I respect your willingmess to share your thoughts.Let's keep exploring bit by bit.

You mentioned the spine area of knives and this in istself has always been a point of contention with me. I will submit to all that even if we are very careful indeed when we use a torch to differentially temper our blades, AND even if we only put heat to the bottom third of the knife, interesting things happen when the quench takes place. That is to say, in my experience, zones of hardness are created as the heat dissipates into the quench medium. So, when all is said and done the etch will show the truth of it.

I don't practice tempering the spine for this reason. Using the method above, I am left with a tough spine which will flex without breaking, and a dead soft ricasso. If I were to guss at approximate RC hardness...I would guess the edge hardness at 57-59 after tempering and the spine at a tough springy 50-52 RC.
Only a guess. However between the spine and edge there is a gradient of hardness. This is a result of a specific heat treatment. The blade is tempered in an oven, and there is no need to temper the spine separately.

Using the brass rod flex test will teach you a lot about thermal cycles.

The ferric chloride etcxh will show you what I mean. Get some blade together, etch them, and under natural light, use a magnifying glass to see what i mean. By the way, buying a knife without an etched surface is like buying a used car without looking under the hood!

Ok, enough for now! Great chatting with you!

shane
 
Nice to find that also basics questions interest, most people talk only about knife brands and new wonder steels solving all problems.

Shane, as a comment: there are at least two things to add.

Someone suggest a method to heat only the edge. Then, you have probably not these differenty hard layers on the spine.

If you on the other hand heat the spine it can harden very much. Many steels, even some not very high percentage of other metals, are also pretty much air hardening, even it is not mentioned in the mill spesification. So, when the edge is in the oil the spine hardens in the air.

What about the tip tempering then?
The tip is the most critical crack prone part of the knife, how you get it good without torch?

Anyway, Shane, we were talking about testing and experimenting.
You gave me a great opportunity to test, thanks.
The steel I use is near O-1 with little bit W added, and I found it really is air hardening also, at least some extent, I do not know how much.
Now I test two different hardening and tempering methods (yours and torch), then I bend both with huge power and measure the difference to crack (or bend and stay bent) if any.
By the way, have you any comments on the opinion that testing mainly forged/not forged difference is quite different thing than testing difference between hand made/ stock removal?

pig
 
Thanks guys, this is a very informative thread. Shane, pig, is there anywheere that I can see some of the knives you fellas have made?
 
Hi Keith,
I did initiate this thread (but Shane did make it really alive) and I want to be the first to thank you about your kind words.
Also encouragement is always important for everybody but very important to me because of I have been feeling some kind of uselessness.(I retired from the computer science field.) I got a brain infarct about year ago and did learn to swallow food (not only into lungs) and walk last summer. I continue my hobby now as before with some minor body balance problems.

I did build my forge 3 years ago and I am pretty much self learned (excluding books).

_______________________________________________

THEN THE MATTER ITSELF, you want to see PICTURES. The picture quality is not as good as could be (old fashioned camera photos and scanning by simple printer scanner cartridge).

_____________________
All the knifes are hand made from forging of blades to details of hilts.
The blade material is a German cold tool steel Bohler K460 (C 0.95%, Mn 1.1%, Cr 0.5%, V 0.12% W 0.55%).

Few new knifes, a general level picture:

http://www.evitech.fi/~tk/general.jpg

From left: A hunter, horn handle. A knife with leather handles. A little bit khanjar type fighter, ebony silver handle. A wire wrapped handle knife.
My Z- like stamp stands for profile of anvil and my initials (TK) with vertical bar forgotten.

The big fighter:

http://www.evitech.fi/~tk/fighter.jpg

The handle black African ebony all metal parts silver. Embedded stamp of my forge in the blade is made of silver plate.
One comment more. I did see a comment in this forum about a very thin tip small knife : "Can I get it the tip already broken?"
Well, if you say the same about my knifes, I undestand it so that the tip is too strong for buyer to broke and he needs help! The tip profile is sharp but it is of the form <>, I mean thick. The thickness of the fighter is half way of the blade 1/4 inch. The lenght of the blade about 9 inch.

The hunter:

Same hunter in the hilt as first in the general picture.

http://www.evitech.fi/~tk/hunter.jpg

a pig from Finland
 
I wish the pictures were a little clearer so that I could make out the knives better. As much as I can make out, I really like. That big fighter looks great.
 
Well Felllas, I probably digressed from the main topic here. My main point is that testing is the only way to determine whether forging is superior to stock removal. However,in order to do that we must be open minded. Also that we must be consistant and focused on the characteristics we want for our knives. Use the same steel, same techniques, vary only stock removal or forged and the number of quenches.

However,I can assure you that there will be gradients of hardness when edge quenching as I described on my earlier post. The treatment I use is very specific. And, I use Texaco Type "A" quenching oil. It makes a tremendous differencr in how the quench changes the steel.
Originally I used Brownell's Tough Quench, a fast quench medium. My results were good but nothing compared to Texaco Type "A". The altered rate of cooling makes a huge difference.

As to destructive testing, my own thoughts are that it should not be the only test performed. Case and point, the Cold Steel Trail Master.
While it is a stock removal blade, attempting to flex one is near impossible with hand pressure. Of coures it is well over the average quarter of an inch that most forged blades in that size are. That does not mean it is superior, just that it has more steel.That's why I suggested like subjects. Forged the same, ground the same. Better chance to see if forged really is better.

Pig asked about tempering. I do all my temepring in an oven. Yep, in the kitchen. I use three different thermometers, and I temper the entire blade. While I have used/seen many methods to temper the spine and edge this is the one that produced the results.

I will say that the idea of the tip being the most likely to crack is more an issue of blade geometry. It is possible to shape a tip that is as strong as any part of the blade. Take a look at a lot of the far eastern blades with a serpentine tip made for peircing armor.

Keith I am sorry, but I don't have any pictures...but you are welcome to come by the shop anytime...with advance notice and we can pound some steel and I'll show you what I mean.

Hope I covered it all. Pig we must test...and test thoroughly, everythnig we claim. A lot of fellows stand behind the data of the "Experts" I am here to tell you that you are on the right track when you ask the question, "Is forged better?"

My opinion is "You bet it is!" If could make a superior quality knife by stock removal I would. But I bel;ieve this is the way to go!
But just saying that is not enough. I HAVE to prove it. No matter what anybody tells me, I have to know. Otherwise when my customers ask about the steel my response will be hollow quotes from somebody I have never met.

I apologize if I got too far off track.

Have a good day!
shane
 
Well everybody on line,
we agree upon importance of testing. The emphasise of the basic idea is important by itself.

What I originally did mean was to encourage lot of smiths actually do separate tests and at detail level PUBLISH RESULTS. THE PUBLISHING IS THE KEY WORD: As for example: "I used bare carbon steel, and forged to geometry A and did use tempering B. I did bend it in a wise way C and it did crack with power D and so and so on."

Because there are so many things to test, the whole workload would be useful to divide using this kind of discussion forum and wide smith network. Everybody tests what seems to be interesting and all together get lot of new knowledge.
I (a hobby smith) even tried to publish one humble test of mine, not to be respected and useful to real professionals but give an example of the basic idea.

However, at least I have even now got lot of useful ideas. I think I will move to bare carbon steels (at least for a while) and forget about fancy alloys. Then I do not need to bother about air hardening and the situation that I must temper the spine with torch. The I can use Shane's technique.

By the way, many expert smiths (Jim Hrisoulas for example) quench the blade tip down and temper separately the spine. At least in his books this is an advice!

Are there any practical comparison of these two "schools"?

pig
 
I believe you. Testing and publishing are the way to go! I wish more of the major maker would publish there results. Even the major publications do not produce the results of their testing!

Let's start a trend where we demand the specific results be published for all to see. No more generalizations.

As a matter of fact, I'll write a letter next week to the magazines in this country who fail to do so. Let the chips fall where they may!

Thanks for the great thread pig!

shane
 
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