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Main Boards => Hunting Knives and Crafters => Topic started by: Scott Roush on July 19, 2010, 09:38:00 AM
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I've been getting more into hidden tangs now and was wondering what the easiest way to forge a stick tang from from wide stock. I've only been able to get 1 1/2" x 1/4" 1084 from Aldo and I find it very easy to forge the blades.... but what about the tang? So far, I've just narrowed it down a bit on the anvil and then ground the rest... but it's such a waste of steel...
thanks a lot for any suggestions!
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Scott,
I try to judge the amount of material to displace into the tang and hold that part on the edge of the anvil striking the material only on the part that is on the anvil. Notice that the hammer is flush with the anvil edge.
Here is how I choke the material in and toward the rear of the blade.
(http://farm4.static.flickr.com/3246/3032725531_4f86ed5113.jpg)
(http://farm4.static.flickr.com/3594/3677026710_6d9d6ef68f_o.jpg)
Then just hammer where I think it needs to go. I keep drawing the material in much the same way from all sides. The clsoer to the anvil edge, the lighter and more careful I have to be. Accuracy is important, so take your time. Here are a few shots along the way. This is a small blade, but the principle is the same for large blades. Lin
(http://farm4.static.flickr.com/3629/3677026638_806fd86cbb_o.jpg)
(http://farm4.static.flickr.com/3655/3676216893_a621f14277_o.jpg)
(http://farm3.static.flickr.com/2651/3677031572_5beff70f5b_o.jpg)
(http://farm3.static.flickr.com/2574/3677031654_be4f763159_o.jpg)
(http://farm4.static.flickr.com/3619/3677031768_51753c2425_o.jpg)
(http://farm4.static.flickr.com/3631/3676217357_9d5b3eaa04_o.jpg)
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Perfect tutorial, Lin.
Scott, you may not have as good of aim as Lin does when starting out, so you can make a guillotine fuller to "set" the tang shoulders at the beginning of the tang then work it down from there.
I'll show you in a couple weeks.
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Thanks guys... I'm basically trying as you suggest, but starting with such wide/thin (1 1/2" x 1/4")stock, the steel wants to cave in, then I try to flatten, etc. I did notice in those pictures that you leave your tang wider than what I have... I guess that would cut down on the work!
Karl... I made a Godzilla guillotine and it works great for some things, but I still have the issue of the edges wanting to bend over. The problem with my 'Godzilla' is that there is too much lateral movement... I need to make a beefier 'pivot' point I think...
Anyway.. I feel like I would rather have thicker, more narrow steel to work with and things would be easier....
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Scott,
What kind of hammer are you using? Lin
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Scott, here's another thought:
You mention the "edges wanting to bend over".
That says something to me.
It says you may not be getting enough heat into your steel. If only the edges are folding over, then maybe only the outside edges are hot!
Or, at least, hotter than the middle portions of your bar. Hence, they move more.
You need to heat your steel through and through!
Forge HOT!!
We'll take care of excess grain growth when the forging is done.
Forge HOT!!
Forge HOT!!
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Lin.. I'm using a 3 lb drilling hammer for heavy forging and a 2 lb Hofi type for flattening and lighter stuff.
Good point Karl... I tend to be pretty conservative on my heats...
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What the guys above said. Also, don't try to move it all at once. GET IT HOT and start the taper slowly! A couple of blows while in the guillitine tool to get things moving properly is all it takes.
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I think the guys are right. I have to agree that your steel needs to be hotter. Also when it starts flaring too much, turn it over (90 degrees)and work it the other way, back and forth. Lin
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and dont hit it when it is too cold...like they said forge hot. takes quite a bit of forging for "hammer control" also. But again Scott, you are ahead of the curve judging by your pics.
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forging hot! hot damn I moved some steel today... thanks a lot!
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Great advice here for sure, for years I was forging on the lower end of the curve. Then I met Jimmy Fikes and started working some with him, among the things he taught me was to GET IT HOT and HIT IT HARD!
When I say hot, i mean bright orange to yellow, yes I understand that defies most common wisdom, but when I started forging in this manner a few things happend- Steel started to move easily, allowing me much more "input" on the steel. The blades really started to "come to life" during heat treat, which is probably due more to the normalization/thermal cycles run after all the "hot" forging.
Dont be afraid, but do have fun.
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Originally posted by Lamey:
The blades really started to "come to life" during heat treat, which is probably due more to the normalization/thermal cycles run after all the "hot" forging.
Dont be afraid, but do have fun.
That's exactly correct, Matt.
You'll be doing the steel - and yourself - a favor by forging hot, but then you have the ultimate responsibility and need to reduce and equalize the grain structure following the forging cycle.
This is a VERY! specific process that behooves the maker to learn so as to get the most out of the steel and minimize certain failure if not done correctly.
It's not difficult - but it is extremely necessary.
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Experience is speaking in the above two posts. New guys please take it to heart.
I have found that to accomplish the necessary tasks to have the best blade it takes my absolute full attention. I suspect this may be why some makers only work alone and dont have folks over to watch.
I can allay some of the danger by adjusting my forge hot enough, but not TOO hot for the task. Develope good forging habits and know your steel. When you get these things down, you can work in a crowd and make a good blade. Well almost. Lin
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"Good food is not fast and fast food is not good." Thats the long and the short of it. A well made, properly forged blade is a blade that the maker can take pride in and the customer can believe in. The maker has taken the time to understand the nature of the steel he is working with and has done his best to manipulate that steel in such a way as to get every bit of potential from it. Forging it "HOT" is a terrible idea and generally ruins any benifit that the proper forging process puts into a blade. Correct heat treatment starts with the first thermal cycles and the first hammer blows and can go wrong at any time there after. It is true that you can "correct" grain growth at the end with normalizings, fast quenches and so on, but this is a "band aid" or a "good enough" approach to knifemaking. Once any carbon steel reaches nonmagnetic it is at proper forging temp. Getting it hotter makes it easier to forge but increases grain growth and cancels out alot of the benifits of the forging in the first place. Yes you can "refine" the grain later but you can't get back to where you started and you won't have the quality of blade you could have had by taking the time necessary to properly forge the blade in the first place. At just above nonmagnetic you should have almost no visable scale coming off your steel when you forge it. Thats a good indicator of proper forging temp and correct forge atmosphere.
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...which behooves each and every maker to "filter" all the information he receives as best he can and put to use those things which benefit him the most.
I make a lot of Damascus. If I was to forge my Damascus blades at barely over non-magnetic, I'd have welds tearing all over the place. That stuff needs to be forged at almost a welding heat.
At the Master Smith level, those very Damascus blades perform exceedingly well when subjected to abusive tests following proper grain reduction and thermal/quenching cycles.
We deal with a lot of different steels.
Saying "..you can "refine" the grain later but you can't get back to where you started.." doesn't hold water.
How do you think the steel mill got it "to where you started" in the first place? They had aaalllll kinds of grain growth and distortions and got it "to where you started" by simple grain reduction and properly controlled thermal cycles and quenches.
It's pretty easy stuff.
If they can do it - we can do it, and we DO do it on a daily basis.
I recently sent two knives - one in my 5160 and one in W2 - to a fellow in Texas who tortured them side by side with a Randall fighter - one of the most respected names in the knife industry - and a fighter in the high dollar S30V. My knives left them BOTH! in the dust.
Even I was impressed.
And both of mine were forged hot, to minimize the number of forging cycles, and properly treated post-forging.
This poor old cat has been skinned countless times.
Good thing we have nice knives to do it with!
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my ears are perked on this discussion... great stuff.
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Scott, this is simply the tip of an "iceberg" that has been floating around the ocean for decades.
It's important that we understand the knife world is accompanied by many philosophies, different "schools", etc.
But, behind it all is the steel industry itself that is made up of people far smarter than most of us when it comes to metallurgy.
It's what they do.
Chris knows full well that I am a close acquaintance and student of Ed Fowler, a man who I respect whole heartedly.
Ed's main focus is 52100, a steel which is prone to extreme grain growth when we exceed about 1500 degrees. That's why Chris talks about forging at not much over non-mag.
When we deal with stuff like 1084 and W1/2, we're working with steel that has much higher levels of vanadium, which those "smart" guys in the steel industry put in there to reduce and minimize and control grain growth.
So our forging temps become far less of an issue. That very vanadium then also contributes with vanadium carbides in the hardening process.
(At this point I refer back to the previous post when I mentioned how my W2 performed!)
I went and did Ed Fowler's "Seminar of the High Performance Blade" because I had just acquired 2400 feet of 1 inch square 5160 that was all made in one batch in 1984. Far as I'm concerned, it's the BEST! 5160 being used by any knife maker today.
I had a group of professional hunters from the Outdoor Channel field dress, skin, quarter and cut up for the freezer 8 bucks and 11 does with one of my hunters and never sharpened the knife.
It was forged hot. And I did the proper post forging cycles.
The guy I mentioned above who abused my knives has since ordered a field/camp knife. We're still working on the design, but earlier this week I took out a knife I haven't used in some time, cleaned up the edge, and took it to the wood pile.
I did this in an effort to reacquaint myself with how my 5160, forged down from 1" stock, performed.
I found a 6" diameter piece of oak that I had given to me from a pile of firewood of my neighbor's since they quit burning in their fireplace years ago.
I don't know how old this piece was.
But when I started chopping on it, it was like whacking a concrete block. I could barely get through the bark!
So, I chopped away until I felt it was certainly enough abuse to determine integrity of the blade.
She still sliced through paper with no snags, and shaved hair like I had done no cutting at all.
Do I want more from my knives?
Nope.
Do I forge them hot?
Yep.
Do I take responsibility for my grain growth and put it back where it needs to be before hardening"
Yep.
The picture you see below is not after chopping on some pine 2X4. It's after beating relentlessly on solid oak that laughed at me!
The next knife I forge, I'll forge hot.
(http://i28.photobucket.com/albums/c247/kbaknife/Knives%2010/test-a-2.jpg)
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thanks Karl... it all makes sense and makes me glad that I'm sticking with 1084 for right now. I also need to spend more time abusing my knives....
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A large number of my knives are forged from load control shaft 5160, the same times and temps that are used with the virgin 52100 that Mr. Fowler and I use are used with the 5160 to achieve almost as good of performance. "Industry" standards have very little to do with knifemaking standards, temps vary by many hundreds of degrees and industry guidelines are just that, for industry uses. Like Karl I test my knives, every one. One in ten is tested to destruction. On average I can expect 400 to 500 clean cuts on 1/2 inch hemp rope and between 8 and 12 180 degree bends before the edge cracks. The last blade tested has done 9 180's and will be tested further at the next High Performance Knife Seminar In WY. I forge the way I forge not only because I was taught this way by Ed Fowler, but because I have tested these methods and find they work. I don't understand all the fancy words and metalurgical formulas but Rex Walter, one of the most respected metalurgist' in the industry says that what we do works, that forging hot results in unrepairable grain growth, and results in an inferior blade. We are all free to do as we please, this is why I do what I do. I am by no means an expert or a master smith, only a knifemaker who will stand behind my work. For a more detailed explanation of High Endurance Performance Knifemaking feel free to visit. Knifetalkonline, Ed Fowlers web site. It has answers to almost any question you might have. You might even find Karl there once and a while!
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I stand behind everything that Ed does.
He is one of the major factors in my 5160 success.
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I haven't been taught by any of the master smiths, nor stood over their forge watching. But I do know people who's livelihood is in the proper heat treatment of steel (and other metals) where the tolerances are literally a matter of life and death.
To say that working metal hot results is unrepairable grain growth is in direct contradiction to everything learned in the science of metallurgy in the last 50+ years (and I'm only counting that far back b/c that's the earliest X-ray diffraction data I'm aware of).
There are dangers to working steel too cold, and I haven't seen those mentioned here yet. There are three temperatures to be concerned about. The first, Ac1, is "the point at which the shift from alpha iron to gamma iron first begins." Uh, simply means the ability of carbon to move around in the steel increases, but there still isn't enough heat to break the heavier carbide bonds. If you hang around this temperature for too long, either by forging at too low of a heat or taking too long to reach non-magnetic (which the the second temp to be concerned about Ac2) you get carbon segregation and banding in the steel. The worse this problem becomes, the longer you need to hold the steel at the third temperature (Ac3 or Acm) to properly normalize the steel.
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Strange how this thread has evolved.
The knife world is a big place, and it is occupied by lots of people, makers, enthusiasts, etc.
It's the people we choose to travel our chosen paths with that make the entire adventure worthwhile.
The knives, and how they are created, are almost secondary.
Not quite - but almost.
More like hand-in-hand.
Without the other, neither one has any value.
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As Karl pointed out this could go on forever. The proof is in the pudding. If you are a knifemaker testing your knives and getting good results then whatever you are doing is working, go with it! As far as the big words, again, I don't know about that. I do know that while banding is bad in industry because of the variety of ways a part will be stressed due to machining, temerature, pressure, etc, it is a good thing, and a goal, in the type of knives I make. Great care is taken to promote banding in the grain of the steel from tang to tip. It adds strengh and toughness, much like the grain in wood.
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To back up a little bit, I would be very interested to learn more about the knives that "Lamey" talked about forging at a yellow heat. That seems a little to hot to me and I know you said that in your post. What is the reasoning, beyond the ease of forging? What steel are you using and how do you treat it, hardening and tempering wise? If your getting good results that is very interesting to me. Well done. How are you testing your finished knives?
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Chris, most of what I forge is W2 or 1095. In the case of W2, I start with round bar varying from 1.5" to 2" round, with the 1095 its 3/8" thick. In my view you have less of a chance to induce stress/ harm to the steel by forging the upper end of the limit. You will spend less time in the heat, fewer cycles for the same amount of movement.
There is nothing "harmed" or lost when forging at higher temps, im not keeping the steel at those temps for extended periods of time, and use proper "cycle down" heats toward the end. Ive been to industrial forge operations and they forge on the upper side as well, and are making very critical parts.
After the "cycle down" (dropping the forging temp the last few passes that im basically just getting everything "straight"), i do a fairly standard 3 tier normalization process.
I bring my blades up slowly to 1500 and quinch in Texaco "Tuff" quinch warmed to 120+/-. Depending on the blade and its intended use I will do at least a double temper, sometimes tirple, again depending on the blade and its use.
Ive done alot of testing, chopping both green and dry bamboo (no shortage of that in my yard), rope testing (on the table, using multiple cuts checking abrasion resistance), all kinds of chopping in the woods as well. Also done ALOT of flex testing in the vice (testing flex vs bend on varying differentially hardened blades, finding that perfect "blend" of having enough hard steel not to take a "set").
Ive got over 1000 blades out there, with many hundreds actually being used hard, get lots of feedback from my customers which helps me in my work greatly.
I take great pride in my work, and will put my blades with any made for toughness, performance, ergonomics etc...
Heres a 10" chopper blade pic was forged from 1.5" W2 round bar (started as a 3.5" piece, the blade was 10" x 2" with a 4.5" tang)-
(http://lameycustomknives.com/Site/Contact%20Info._files/100_1521.jpg)
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Originally posted by chris amos:
Great care is taken to promote banding in the grain of the steel from
Chris,
It's been a while since I've visited Ed's site, but the banding you and he are talking about is the micro banding that runs parallel to the edge, right? That's still an even distribution.
Take a blade and do half a dozen or so cycles at just below non-magnetic. What you'll end up with is not the even micro banding; it's fairly large and random swirls and bands visible with the naked eye. You're right, "great care" must be taken to get the fine structure and distribution you're going for.
Forging too much at too low of a temperature causes problems that DO need to be corrected by a longer soak time to normalize... which is beyond the capabilities of most here who do not have proper temperature controls on their forge. It's very easy for beginning smiths, or for most hobby smiths, to fall into the trap of working the blade when it's too cold.
IMO, it's easier to forge at a higher temperature and then correct any grain growth with proper reducing heats after forging. That's managable by most smiths and results in a fine grain with even particle distributions. I don't see that result as evidence of "unrepairable grain growth" (though I must admit to getting a smile knowing I made Ed laugh with my comment :wavey: )
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Chris and Karl, it sounds like you both very much have your methods down and although have both atended Mr Fowler's workshop have taken slightly different philosphies away from it. That's the way I see it, as different philosophies. Both of your methods work for the type of knife you want to build and for the performance you want to see.
Whereas most, especially budding knife makers, are happy with just making a knife that will cut and somewhat hold an edge along with looking decent, you both have taken your work to a different level by tailoring your methods with a particular performance in mind. That's not a bad thing. It shows a lot of experience and testing has gone into it.
Getting it HOT is relative. The only way to know just how hot is to describe it in degrees, but as a rule, the more mass in a piece of steel, the more heat you need to be able to move it with the same size hammer. Then reduce the heat as the material gets thinner or in smaller cross sections.
Matt said something interesting about bend and flex which goes along with what I try to acheive in my knives. Like him, I want my blades to flex as far as possible without taking set.
Lin
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I also want to add that I do what works for me, It may not work for some one else. Im not saying its the "only" way, but for me it works the best. Ive blended a bit from different makers, different books, and 15+ years of being a fanatic about forging, heat treating and good cutting knives.
Was also fortunate enough to "refine" and put some important "touches" on my skills with the best person ive ever seen with a hammer, or blade, Jimmy Fikes. If any of the old timers here were fortunate enough to see him in action years ago at some of the Hammer Ins (He was a major influence in starting Ashoken) you will know what im talking about.
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I added an important picture that helps me explain how I start the tang back at the beginning of the thread. Page 1
Lin
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great pics Lin, do you ever "set" your choil, then pull your edge down from the "set"?
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Thats a great looking blade Lamey, nice job! Its good to hear you are into serious testing. Sounds like you have what works for you worked out. About the banding, perfectly even grain isn't what I am looking for when I etch a blade. A blade with the uneven, swirls and grain pattern will, in my destructive testing, always be stronger. Think of it like cement. A cement slab for a building or other heavy use is mixed with aggregate of all sizes from sand to gravel to large rock, maybe 1 1/2 inches in diameter. These variations in size distrubute the stress's over a larger area and interlock to create a stronger structure. A cement with a small aggregate only like sand will go down smoothly and look great, like plaster. But it doesn't have any strength. You can break an inch thick piece of plaster with your hands. The "rules" used in industry are for making money. They are the largest margins for error allowable to achieve an exceptable product. Each formula and pour I am sure is different, some are certainly more exacting than others depending of the purpose of the steel. The margins that I use, and that work for me, and are specialized for my purpose. my desires for the steel and the industry standards are not the same thing. That's ok, just like all you guys have said, you have found what works for you and we are all looking for a way to make our knives better. That's what it's all about.
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Matt,
I think I know what you mean. I usually do it just like the photo shows, but I never say never. I forge my main stock slightly larger than my finish ricasso size and pull everything from that outward, only having to resquare the ricasso some. If the blade is a particularly wide one, I may have to start with wider stock, pull down the choil, then reduce the ricasso upward, the net effect dropping the choil even more. Sometimes I will start with the tang just to see if I can forge it backwards. Aint knife makers crazy? Lin