Definition of "forged"...

[Ed Fowler]

Andrew: You have brought up a very significant aspect of forging.

All Steel is forged! (unless it is cast to shape)

There is very little difference between the stock removal blade and the blade that is forged to shape from bar stock that is close to the size of the finished blade. Take a 3/16 inch thick X 1 inch bar, heat it up and give it a few swats with a hammer and if you have not heated too hot or cooled too quick you may have improved the steel some. But there is a whole lot more to the equation.

Grain size is amoung the most significant variables as it also functions as an indicator of forging temperatures and ratios.

That is why I mentioned in a previous post that the most significant aspect of a forged blade is a statement of the ratio reduction by forging. Another significant aspect is forging temperatures and thermal cycles.

I believe that through thermal cycles and some planning the average stock removal blade could compete very favorably with most "forged to shape blades".

We have been working on understanding the forged blade for over 30 years, the team has varied greatly over the years, but always a team . Last week Rex, our metalurgist and I spent four very intense days and learned a lot, also came up with some significant questions. All understanding to date matured a lot in the last 3 months. Quite an experience!

[Andrew Garrett]

I don't want to get too far off track here Ed, but you triggered some thoughts I want to share with you in the hope that you can help me understand steel a bit better.

In my minds eye, this is how I 'picture' forging works. Don't laugh, but I think of forging in terms of link sausage. Yes...link sausage. With the skin on a link of raw sausage, you can shape and mold to you hearts content without losing any meat. The integrity of 'skin' is unbroken regardless of the shape you achieve so the 'grain' is intact and at its strongest. If I used a tool to cut away some meat in order to achieve my final shape, then I expose the 'grain' of the meat creating a sort of opening in the stucture that permits easier breakage. The best way I can picture this in my head is when I look at my favorite back-scratcher. It's one of those bamboo things that flexes real easy, but on the end where the bamboo has been bent over to provide the scratching tines, it has also been sanded (or 'ground' if you will) across the grain. This presented an 'opening' in the grain which has since started to split a little. In my head, I think of the point on a stock-removal knife the same way I think of that bamboo. It has an 'open' and thus, a weaker (even if very slightly) grain structure.

I know I'm looking at it all wrong, but maybe you can tell me why.

Thanks,
Andy

[Ed Fowler]

Andy:
Your thoughts are music to my ears!!!

You have the idea, your bamboo analogy is exactly on the money.

Now consider the thought if reduction by forging ratios.
The larger your sausage, the greater your ability (opportunity) to refine and alaign the internal structures or grain. Rolling requires higher temperatures and negates some of the properties we seek in high performance blades, therefore reduction by forging at a lower temp and with the right plan affords the opportunity for finer grain through forging and thermal cycles.

I just picked up a book, "Prevention of Fatigue of Metals" it has a lot of ideas, good stuff. I wish the author was still alive so we could talk to him. Rex and I just put in a very intense week investigating where we are and working on some new stuff.

Some microstructers can provide a crystaline fillet within the steel, that is why multiple quench and edge quench can be beneficial.

We stress tested what I call a 52100 'Wootz' structure that was amazing and provided a lot of knowledge and questions that will only be answered when Rex gets aback to the lab.
Don't be reluctant to ask more questions if you like, the more bladesmiths who seek great blades the greater our success.

Thanks Friend

[Andrew Garrett]

Keep talking Ed. I'm glued to this stuff!

[Ed Fowler]

Andrew:
For some more ideas, go to the high performance section and read about the torque wrench test, this little addition to our testing regimen has provided a great deal of information.

[Ed Fowler]

Andrew: While Rex was here we video taped 6 hours of our thoughts on forging, both theory and practice. I got to watch some of it tonight, if all goes well it will soon be available to all. It is not just one event that puts the best forging a blade has to offer, but a very careful but simple system that took over 30 years to develop.

We did not have the book on metal fatigue when we filmed the events. At the time we had some questions that evaded explanation, after reading the book for the second time I think we have more answers.

One aspect that kind of hurt my feelings when Rex first mentioned it was the fact that all we have acomplished came from a shop that is devoid of "high tech" equipment. Most of what we have learned has been through simple testing of blades doing what knives do. You and anyone who makes knives has all the equipment necessairy. All the bladesmith needs is a desire, and couriosity.

The cornerstone of our experiments is my Paragon oven. Without it we could not have achieved the kind of knives we make. Next would be my Mankel 3 burner forge. Everything else that we use (with the exception of belt grinders, buffers and drills etc. is pre 1920.

The Lab that Rex works in is High Tech, he evaluates what we have made, asks a few questions and keeps me busy in the shop for months. The knife making itself does not require high tech, just desire.

[first twin]

I hope none of you mind me stepping in here with a question but this thread and another similar thread have confused me. It seems that as I read these forging threads they start out asking about forging and end up talking about hardening and tempering the steel after they have shaped it. From what I gather many knives start out forged and end up being ground on surface grinders and belt grinders but that is another issue altogether. To my question. Assume that I grind a blade identical to a blade of Ed's, same shape, same steel, and he heat treats it. Would it be inferior to Ed's forged blade based solely on the fact that mine was ground and his was forged. If so how and why? Please feel free to use some detail if necessary.

[fitzo]

The following link has not been listed in this thread anywhere, but it contains the article Romey mentioned. The third article is a pertinent viewpoint from another ABS MS, Kevin Cashen, and merits "airtime," so to speak. It is also the reason for the off-forum discussion that led to this thread.

http://www.cashenblades.com/hype.html

I think it important that those interested in this discussion read Kevin's comments, too. The other two articles on Kevin's page also make for some humorous and interesting additional reading.

[Ed Fowler]

First Twin: you are most welcome, ask any questions you like.

I will start off by saying that there is no such thing as a bad knife. If a maker wishes to make his kind of knife and is proud of it, that is all that matters. We are all free to make what we want to make.

I chose to make the kind of knives I seek when I experienced knife failure at times when I truly needed one.

Years ago Wayne and I made two knives from the same steel, one stock removal, the other forged. The initial stock was 3/8ths X 2 therefore there was not a great amount of mechanical reduction by forging, but as much as we could do. We then triple puenched them. On the first quench the difference in the steel we were working with was apparent. The scale from the quench peeled off of the forged blade, but stuck tenaciously to the stock removal blade. Through all three quenches the forged blade out performed the stock removal blade. By performance I am talking about edge flex and cut. The test is in my book Knife Talk I.

The reason the forged blade could outperform the stock removal blade was (I feel) due to the refined grain in the forged blade.

Forging provides the opportunity to work the steel, the greater the ratio of reduction by forging the greater the potential of the steel. (I believe) There can a whole lot more to forging than heating up a piece of steel and beating it into shape. We have been investigating the influence of forging temps,theremal cycles and reduction ratios for over 30 years and finally we have some answers. Rex is going to analyse the test blade we just worked on and I am anxious to see if what we believe actually happened. All previous lab work points in the same direction.

Some grinding will not hurt a blade, actually it is beneficial. The best potential steel lies below the surface of the blade as forged. Years ago it was believed that a forged blade had to be broken in, all the break in stage did was remove decarb and forging and hardening errors.

You mentioned that all discussions about forging lead to heat treat. It is a natural progression, everything before heat treat sets the table for the results of the heat treat system. The proof of quality is in testing the blade. Every bladesmith has everything he needs to evaluate the performance potential of his blade in his shop. Steel rod for edge flex, hemp rope to test cut and a vice to test over all toughness of the blade.

I seriously doubt that any knife maker can afford the equipment to know the science behind performance. That is why Rex is the man of science, he has spent a lifetime studeing the science. There have been and are other knife makers working toward the same goal, it is only through sharing information and knowledge that we have achieved what we have. We are fortunate to have a team working on our goals, I know of no single man who could possibly do it alone.

I believe that stock removal makers who chose to push their steel to the limit can do so and make better knives than most of the forged blades out there. The least expensive investment we make is in the steel we use, Rex and I bought our steel as scrap. It was great scrap, all the same pour, high quality, closed center and made right. It is large enough stock 5 1/2 round bars that we have the opportunity to enjoy it as much as we wish.

I do not mean to say that knife makers should not endeavor to explore the science, many books have contributed, but many more lead to mediocracy.

It is through the investiment of quality time and sweat that steel gains its value.

I hope that I answered your question, if not please ask again.

[sdcb27]

what Fitz said.. First twin, my advice to you is to read , read everything you can. Some people choose to beleive mystery and legend and some choose to beleive science, its up to you and only you to exsperiment and decide. Dont beleive ANYones hype, just use it to seek out the truth and what can make you the very best knife you can. If you are always strive for better you cannot ever be satified and youll always learn and improve.

[Ray Rogers]

Thanks, Fitz for pointing us to Kevin's articles. I read every word of all three of the articles and couldn't agree more with his findings and opinions....

[Harry Mathews]

Thanks for all the good info and reference material. We will continue to read as much technical stuff as we can find. This area is very interesting and I think some hands on testing will be a great help. Harry and I can't wait to get the forge working. Should happen a week or two after the Guild Show. Until then, and probably after, we will just grind away on our CPMS30V and CPM3V.

[first twin]

Sorry about the previous post. I didn't realize I was signed on as Harry(Second Twin).
I do appreciate all the input. There is a wealth on information on these forums. Harry and I both look forward to getting into forging and doing a little testing on our own. I am not sure I will ever be able to test a good knife that I have made to destruction. I would have no problems testing one of Harry's though.

[Ed Fowler]

Charlie: Don't be afraid to test a knife to destruction, that blade is finished, the only one that matters is the next one. Rex and I just destroyed a blade that I put over 40 hours in. The informatin from that blade will hopefully make a difference in the next. WE can read all we want to, but that actual blade is a combinatin of all experience and only through testing it all in one package can we learn truth. All theory, all dreams are on the left side of the equation, the blade is on the right.

Traditionally "forging" simply means to form or force the metal to shape using "hammers". However, in modern smithing it has also come to include "pressing" the metal to shape. "Rolling" is a specific kind of forming, which is not normally referred to as forging, but may have many of the same effects.

I agree with Ed that forging from lower temps can promote and encourage grain refinement,... thermal cycling in conjunction with forging. However, I think there's a limit to how much. I'm not sure what the actual mechanisms are, whether it's the pressure, stress or shock vibrations that do it. With simple steels the amount of reduction through forging doesn't seem to play that great a roll. I've experiment with 1065 and 1095 and as little as 1/32nd to 1/16th an inch reduction will get the job done much better than thermal cycling alone. I've worked with some new 1/8th hot rolled 1095 recently. And it came with a very course gritty grain. The thermal cycling alone had an effect, but would not reduce the grain to my satisfaction. However, the thermal cycling in conjunction with some light rapid hammering worked great! Quenching this particular steel also had a noticeable effect on the grain size, more so than the normalizing cycles. Multiple quenching did not seem to improve the grain size noticeably, but it did radically "embrittle" it. Anyway, for this particular “batch of steel“, the light forging definitely improved the grain. Not all 1095 is the same, and not all steels respond the same way. Some seem to respond just fine to the thermal cycling alone.

So, if someone were to ask me if forging “in general” makes a better blade , I would have to say,… "maybe".