Functional knives?

Great thread by the way. I am still having trouble envisioning a forged blade not having a dropped edge. Where does the steel go when the bevels are forged?
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I am a little lost on this part too. I understand that in forging the edge on the blank you are going to move material out and probably drop the edge. What I do not understand is why grinding seems to be offered as the only solution to this. Why not just draw the excess material down, cut it off, and finsh forging the edge?

n2s
 
Or after the general shape is forged push the steel that will become the edge inward towards the spine so that it is below the ricasso. now draw the edge and bevels down to even with the ricasso and wala. you have a blade that is forged to shape with the bevels and plunges already in place. It takes a little more pounding to do this but with the idea that forging at the proper temp., does more good things than bad??
 
When you start with larger diameter round stock, 3 inch or more, the bladesmith does not need to forge the edge down in order to achieve the benefits of forging. By the time you have it worked down you have had plenty of opportunity to fully develop the potential of the steel.

All it takes is practice, a 100 pound power hammer, a forge and time. You learn how to work the steel, naturally all the finish work is done with hand held hammers.

For those of you who don't have the equipment to work steel, pick up some modeling clay, put some concentrated dish soap (keeps the clay from sticking on the hammer) on a rubber mallet and work the clay. Try with and without a dropped edge. Your experience will be essentially the same as we know when working steel. You can do it in your kitchen without all the smoke and noise we know. Thhre is only one rule, have fun with it!
 
You are most welcome Keith: A few suggestions, First try a forging from the clay just like you get it. Then try from a round bar or ball, then a try a flat bar, say 1/4 X 1 X 6 inches. Play with it and make as many knives as you like. Make them your way, any way you like. that is what it if for. A plastic mallet will also work. There is only one rule, enjoy the voyage!
 
So what you are saying is, if I understand correctly, is that you are using a power hammer to reduce 3 inch round stock into barstock. For example size 1/4x1x whatever length. Then you use stock removal to grind the profile and bevels. And by forging the barstock, you obtain all the benefits of forging, without the need to forge to shape. Is that right? Brett
 
Brett,

I'm not exactly sure what you mean by "forge to shape". I've watched Ed forge a few blades, and when he's done hammering, it's pretty much to shape. If I'm not mistaken the bevels are included. Everything is just left thick and has to be ground down some later. I don't have a good pic of a blade at that precise moment in time, but here's a few pics of Ed in his shop, that might help answer your question. There's a LOT of forging done before the steel is the size that you see in the first picture. I hope you don't mind me posting these here, Ed.

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-Jose
 
Brett: Presently we start with 5 1/2 inch round stock, Doc forges it down to 3 inch square stock. I then forge it down to billets 1" x 2" on a 100 lb Beaudry power hammer using low temp. (1625f max) and flat dies. Then forge these billets into knives,on a 50 pound Little Giant, again low temp and flat dies in order to work the steel as much as possible. Then comes the hand work, hammer and anvil stuff. The knives are then forged to shape, leaving about the thickness of 2 25 cent pieces around what will be the cutting edge. We keep the edge forged level with the ricasso. From the 3" stock, all hammer blows are to the future cutting edge and sides of the blade, rarely hit the spine with a hammer, thus providing maximum benefit to what will be the cutting edge.. Rough grind, a little oversize then polish to 220 grit. Then harden temper etc. Then final grind to finished knife. All steps are based on well thought out forging practices, backed by photomicrographs and chemical analysis. No measurable carbon loss in finished knife when compared to parent stock.

There is a lot more to it, but this pretty well covers the shaping procedure. Thanks to Rex and his laboratory we keep learning, and have some intersting experiments planned as soon as we can afford them.

I hope this answers your question.
 
''If you want to forge that way, fine, they can be beautiful but you are face to face with a functional design fault.''

Ed, I have to disagree on your point of a drop edge being a functional design fault. Over the years I have forged a lot of work knives for professional shooters here, most of them with dropped edges similar to those shown in Terry's posts, quite a few of them without guards. These guys work every night processing up to 50 animals a night, usually in the dark, these are people who depend on knives that perform well and are efficient . The majority of them actually like that the edge drops below the bottom line of the handle.I have personally worked as pro shooter myself for a few years and used many different knives and have found that I always go back to knives with a dropped edge, nowdays this is all I will use. The type of knife used by anyone for any particular purpose is simply personal taste, I think its a bit over over the top and unfounded to conclude that every hunting knife with a dropped edge has ''a functional design fault''.

Steve,,,,,,,,,
 
Ed: I have seen your video and already heard a lot about what you have to say about the benefits of forging. However, I do wonder, does it really take three inch stock to get benefits of forging? That is virtually impossible to work by a hand-held hammer. I have worked with 52100 in 1-1/8" round stock and I can't hardly imagine trying to work a huge ball bearing! :eek:
 
The way I see it, if forging 3 inch round into barstock makes a blade forged, then virtually all mill run steel could be considered forged blades. Also, what type of oil do you use to quench in? That is quite a flame you got!! Brett
 
Steve F: If you like that kind of knife, use it, enjoy it. For me and my kind of work, I like the blade clean, I seek to reduce as many unnecessairy potential problems as possible through design and the nature of the steel in the blade. To me design is a serious matter, not only is it a matter of convenience for the user it also strongly influences safety.

If your cleints want them and you want to make them go for it.

Steven Roos: I learned early in the game that the greater the the degree of mechanical reduction by forging at appropriate temperature for the steel and in the right manner the greater the potential for increased performance. I do not know what the limits are. I do know that I never had a blade from a 2 inch ball out perform a blade from a 3 inch ball. The five inch stock we use now produces blades that highly out perform the old blades from 3 inch stock. This may be due to several reasons, this steel is very clean and consistent, all from the same pour, a tremendous advantage!

We plan on an experiment in the future starting with a 10 inch or greater size round bar. We will turn the same stock down to several diameters, then forge the resultant bars, (all from the same larger bar) and compare the blades. It is going to cost money and time, but hopefully we will be able to determine the limits of the advantage to the potential blade performance.

Yes it is very labor and time intense working down larger stock. I do it because I deeply want to achieve the highest performance blades possible. It is not within the possibility of many blade smiths who work totally by hand. I would very much like to determine what is necessary and also learn ways of enhancing blades from smaller stock.
Many variables influence the nature of the steel, some are within the realm of all of us. Most significant are many low temp thermal cycles, both while forging and planned normalizing cycles between forging steps. Not to forget heat treating stuff. I could state lots of variables we are working with now, but they are unproven and could be confusing. We will share them when we are sure we are right.

WE hope that the new shop we are building will afford the opportunity to bring together knife makers who share the desire for high performance blades. The more individuals involved the quicker we all learn.
 
Brett: Industry forges most steel at much higher temperature than the 1625f I call the limit. Higher temp forging, (over 1750f) grows grain, low temp forging permitts (or sets the table for) the development of much finer grain. The flame is kind of exagerated by the camera. The oil that I have found to work best for 5160 and 52100 is Texaco Type A. No other quenching oil has worked as well for us.
 
Hello all, sorry for jumping in here so late. This is a very interesting thread. I have been making stock removal knives as a hobby for 4 years and am now making the jump to forging. Many thanks to a lot of you on this thread for the help you have given to me in my quest of the forged blade.

It seems to me that a lot of this thread is about the dropped edge or heal and whether or not it is of consequence in the overall performance of a knife. I personally feel that any tool if used consistently enough will eventually become comfortable to its user. However, the problem arises when we step out of our comfort zone and use the tool to perform a task that is unfamiliar at the moment. In my humble opinion, it is at this time that functionality being built into the tool is of utmost importance. As knife makers we can never know what our knives/tools might be called on to do. More often than not, our knives (with or without the dropped edge) will perform the task without any issue. But the last time I checked “Mr. Murphy” is still alive and doing well… Just ask Mr. Shipman and the unfortunate man out here in Utah that had to amputate his own arm to preserve his life. You never know.

It has been stated that the dropped edge is a natural effect of the forging process when a blade is forged to shape. This statement raises a question with me… What benefit is there in forging a blade that closely to shape? Someone mentioned a maker that forges his blades to about 95%?? of final shape. Does it add anything to functionality or performance level of the final product? It seem to me that the law of diminishing returns would apply here somewhere.

I hope that I am not stepping on anyone’s toes here. I’m just trying to understand, being so new to all of this.

Thanks,
Rick
 
Originally posted by Ed Fowler
Steven Roos: I learned early in the game that the greater the the degree of mechanical reduction by forging at appropriate temperature for the steel and in the right manner the greater the potential for increased performance. I do not know what the limits are. I do know that I never had a blade from a 2 inch ball out perform a blade from a 3 inch ball. The five inch stock we use now produces blades that highly out perform the old blades from 3 inch stock. This may be due to several reasons, this steel is very clean and consistent, all from the same pour, a tremendous advantage!

We plan on an experiment in the future starting with a 10 inch or greater size round bar. We will turn the same stock down to several diameters, then forge the resultant bars, (all from the same larger bar) and compare the blades. It is going to cost money and time, but hopefully we will be able to determine the limits of the advantage to the potential blade performance.

Yes it is very labor and time intense working down larger stock. I do it because I deeply want to achieve the highest performance blades possible. It is not within the possibility of many blade smiths who work totally by hand. I would very much like to determine what is necessary and also learn ways of enhancing blades from smaller stock.
Many variables influence the nature of the steel, some are within the realm of all of us. Most significant are many low temp thermal cycles, both while forging and planned normalizing cycles between forging steps. Not to forget heat treating stuff. I could state lots of variables we are working with now, but they are unproven and could be confusing. We will share them when we are sure we are right.

WE hope that the new shop we are building will afford the opportunity to bring together knife makers who share the desire for high performance blades. The more individuals involved the quicker we all learn.
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I would be very interested to know if there is a absolute maximum stock size where performance levels off. There is a limit to how fine the grain can be...or is there?
 
Jose,

O.K. fess up , who is that in those pictures . We all know it is not Ed as he has no hat on .:D

Baumr: yes sir Mr. Murphy is still alive and kicking. That climber has a major set of balls . I know how bad it hurt using my broken arm. I just could not imagine cutting my arm off .

I have learned a great deal from this thread and have enjoyed it . The one concern I have is that folks keep talking about hunting as if it is the only use for the high performance blade . I carry my Pronghorn daily , and I travel from coast to coast . It has not been used since I got it to clean one game animal but has been worked like a $2 whore in town for shore leave .My idea of performance is that no matter what I have to do my carry blade will do it without hesitation and no quirks . This just my out look on the subject at hand but I carry a fixed blade about 18 hours a day and it is used hard everyday period.Someone elses milage may vary .
 
From my very small knowledge of metallurgy, if grain size is 6, then it cannot get reduced. It can grow, but not reduce. I do not understand the benefit of forging barstock from 10 inch round stock. It cannot reduce grain size, only stock dimensions. I could be wrong, it happens alot. Also, regardless of the steel mills forging temps, theyre still technically forged. But if I grind a blade from it, it is not a forged blade. A forged blade, in my opinion, is one that is forged as close to its final shape as possible, and still account for forge scale and decarb, and in my case, stray hammer marks. Brett
 
Brett: Recducing grain size is the why and what for of forging. From the 5 1/2 inch round bar, our methods have resulted in grain size of 7 to 8 in the spine and 10 to 11 in the area of the cutting edge before hardening and 14 and finer in the hardened portion after hardening and tempering. This was verified by photomicrographs. By placing most of the hammer blows to the area of the cutting edge obviously has some effect. Not only is forging of significance, the nature and number of thermal cycles also highly influences the nature of the resultant steel.

Grain size alone is not the holy grail. 14 and finer, the AND FINER is much more significant than a uniform 14 grain size would be. The nature of the aggregate seems to be the key. The amount of thermal mechanical reduction by forging is what we are all about. Smaller uniform grain size allows grain slip in flexing of hardened steel, grain slip prevents stress risers from forming, thus toughness.

Back when I started forging 5160 I started using 3/8 x 2 inch stock using a 10 puound double jack with a 18 inch steel handle. I immediately noticed greater cutting performance over the 1/4 X 1" stock I had been forging. I could not achieve the performance level of the larger stock from working down the smaller stock. By working the area to be the cutting edge in and out while forging down to the ricasso resulted in higher levels of performance than simply forging the cutting edge to the gants eyebrow. Simple facts. These are the lessons we have learned, others may be able to achieve high performance blades using their methods.

The guiding light in all the experiments was the testing of blades. No one can achieve high performace without the benefit of thorough testing. Thus the edge flex and rope slicing tests, followed by repeated 180 degree flexes to determin the exact limits of the blade. You can skin animals all week and not achieve the knowledge gained by flexing the edge and slicing a couple feet of rope.
 
I like this discussion. Many good points and many more questions keep coming up.

I must agree with Steve F. on the droped edge issue. I like a droped edge for many reasons. First of all is the added width to the blade giving it a more accute angle to the spine. The easier the knife cuts, the less pressure needs to be exerted and therefore stress on the knife. I also like the edge to be close to the level of my fingers for cutting on flat surfaces. This is the reason for the droped edge on a chefs knife. It allows the user more of the blade for cutting. Another reason is the life of the knife. There is more material to sharpen away before the edge is just too thick to be serviceable. I know it sounds like a small issue, but I have seen several old knives that were truly worn out from sharpening. Regardless of how well a knife performs, it will need sharpening eventually. I also like the asthetics of a dropped edge. The wider blade on many bowies provides amore balanced look to me. I like elegant horses, guns and...of course knives.

As for forging large diamiter bars. I have not found any benefit from this practice. Once a steel is annealed properly, the grain size is as small as it will get, and as uniform. Essentially, all the grain manipulation done during forging is erased, and replaced with a sress free and uniformly disperssed peice of steel in a new shape. Stress is the biggest killer in knife blades. Forging builds A LOT of stress in the steel. In order to releive it, the steel must be normalized and annealed properly. Doing this erases all the grain manipulation with exception of grain flow. This is of course providing the forging was done properly at lower temperature ranges to prevent enlarged grain to begin with. If this happens, the steel needs be be annealed several time to reverse the effect.

The major benefit from forging is the allighnment of the steels grain with the flow of the blade. I worked for a Caterpillar dealership for three years, and went through a failure analysis class. After looking at failed engine parts, both forged and stock removed, it was clear as to the benefits of this effect from forging. The stock removed parts had cleaner shears or breaks with small shear faces or burrs from the initial fracture before plastic deformation took over and separated the part. The forged peices tended to be more twisted and mangled, but actually separated fewer times. Crank shaft failures were usually sheared or cracked in stock removed, and twists or deformation in forged cranks. All of this is due to the flow of the steels grain.
 
Steven Roose: Sorry I did not answer you question. The 14 grain size we have achieved exceeds what once was the theoritical limit in grain size refinement in 52100 steel. New steel, is a significant contribution. The and finer is finer than we can currently measure. Who knows where the limit is? That is why the experiment with the 10 inch round. There are other variables we can play with. This is the fun stuff!
 
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