Video of my first 90 bend flex test.

Pretty cool, Alan! Are you getting ready to test for the ABS or something?
 
MrPurple said:
Pretty cool, Alan! Are you getting ready to test for the ABS or something?
Click to expand...
Nah....It was just a kind of personal test of my knives.

I read about all you other guys who had put their knives to this type of impressive test for so long here, so I wanted to know if my knives could ...or rather, if "I" and my system of heat-treating, could walk the walk and not just talk the talk...
I wanted to know how everything stacks up for me.

and...

Im also a member of Ed Fowlers new forum.
And there Ed sorta dropped the hint to us guys to take one of our knives and see what it can do.

I got the new DVD from Ed and on it you see how to do the 180 flex test.
The moment I saw him do that type of test I knew I might want to give it a try. (Why I had to do this on the coldest day of the year?...I dont know)

And as you can see from this 2nd video clip, I really didnt expect to finish my 180 bend.

http://www.youtube.com/watch?v=pmkuZCUoW04

As I was pulling the knife back over the top, I kept thinking; "Here would be a good place to stop.... and here would be another good place to stop..."
 
Was that a torque wrench setup you used? If so, did you record how much force it took until it took a permanent bend? Would you be interested in repeating the test on a fully hardened and tempered piece to see how it compares in terms of force required?
 
nice alan i like to watch your little video clips, i my self just forged out a JD load shaft and have a 6 foot piece of 1 1/2 inch diameter virgin 52100 that im going to be working once i get my burner made from hybridburners.
 
the possum said:
Was that a torque wrench setup you used? If so, did you record how much force it took until it took a permanent bend?
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OK,,,about that...It is one of them "clicking" torque wrenches. You set it for a foot lbs setting and it would click when it reached that point of torque.
as far as i can remember, this was the only time in the last 10 years i have owned that tool that i ever used it.

Did I record the foot lbs I used to bend the knife?...no
...But in my defense you have to understand, ...
I really didn't think this would work. I didnt think the knife would bend at all...

Now next time, yes, i will pay more attention, I will take note of the foot lbs of torque it takes to start the bend.

I also will not try to do this type of test ON THE COLDEST DAY OF THE YEAR!
You cant see in the first video too well, but I was doing many parts of it with my eyes closed when I would really yank down on the knife. I was totally 100% sure it was about to snap..

I kept stopping to check on what the problem was?

In the Fowler video he bends the knife faster, but I didnt know what to expect from my blade. (Other than it snapping)

In the 2nd video you see it start to bend more, I think this was due to me being more sure of myself, and the steel warming up too.
 
Alan Molstad said:
Now next time, yes, i will pay more attention, I will take note of the foot lbs of torque it takes to start the bend.
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It's not the force at the start (when you just start to flex it) that matters. That only depends on the steel thickness and length; not heat treat. It's at what point did it take a permanent warp/set, and not return to true on its own anymore.

Tim Zowada demonstrated something along these lines at Ashokan this year; you might want to search for it.
 
Thanks, possum. I'm never sure how to approach this. My 'beating around the bush' was more like 'walking on eggshells' here.

Alan, I'm sorry for asking a loaded question, but I think if you research what possum is talking about, you'll see why. This topic is a lot more like religion than science, and I'm not very good at being political.

BTW, congratulations on your successful heat treating! It's quite obvious that you've got the idea. Now, the question is: why is this the idea, and why is it important (or not important)?
 
the possum said:
It's at what point did it take a permanent warp/set, and not return to true on its own anymore.
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It took a lot to bend it.
It sure felt to me like it actually took too much torque to bend it.

I will have to watch that first clip again to see for sure, but as I remember it, I kept stopping to see what the heck was wrong? and why would it not start to bend?
 
MrPurple said:
Now, the question is: why ...?
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My answer...
Back in High School my best friend got a new car....It was what they called in the 70s a "Muscle Car"...
It was a GTO.....

About the first weekend after he got the car , I was with him when we got pulled over by the cops for speeding...
We were doing about 130+ mph in a 55 zone.
We were underage so they called our parents.

Our moms kept asking us, "Why were you guys speeding in such a new car?"
Our dads never asked us anything...

Much like knowing this data about my knife now from testing it like this.

If you have to ask why, you dont understand.
If you understand, you dont have to ask why....

I just needed to know if my knives could do this....
I have been reading here on this forums for a while, and in BLADE magazine about guys who are seeking to test their knives for the ABS.

I could not help but call into question if my own blades could be equal to the challenge you guys ask of your own knives too?

Now I guessed that my heat-treatments are good enough to allow the knife to flex to 90...but to turn back and go 180?....
That I didnt know...
And there is only one way to find out.

I just watched the first video clip again, and Im still amused by the trepidation of that first pull....
 
If it were me I would see how much torque my knife could take to bend 90 degrees one time, not how many bends it could take. I don't want my knife to bend at all.

Edit: I would design my knife to take as much torque as possible, of course.
 
Yes, Different makers have different ideas, and this leads to different designs for their knives.

My idea for the world's best working man's knife, is that it will not break under the normal stress of my own job.
I have one of them jobs in outdoor construction where I dont always get to see what Im cutting.
Many times I got to cut tree roots out of pipes that are under a foot of black water.

Thus, you can see the need I have to design a knife thats NOT GOING TO SNAP no matter what Im doing.
I cant use any knife at all that has even a slight chance that it is going to break in two just because I decide to twist it around a bit.!

Yes, the torque question is VERY important to know..
If I want to be able to trust my blades in tight places where I dont have the room to fool around,then I got to answer the torque questions now before I get into them situations...and now I know just how much weight it takes to bend my blades..and if they snap on a guy when they shouldn't.

...Hence the real value of knowing how my blades react to a 90 and 180 flex test..
 
Alan Molstad said:
Much like knowing this data about my knife now from testing it like this.

If you have to ask why, you dont understand.
If you understand, you dont have to ask why....

I just needed to know if my knives could do this....
I have been reading here on this forums for a while, and in BLADE magazine about guys who are seeking to test their knives for the ABS.

I could not help but call into question if my own blades could be equal to the challenge you guys ask of your own knives too?
Click to expand...

Hey Alan,
I'm not questioning whether or not your knifemaking and heat treating skills are capable -- you've proven that!

The reason that possum and I were calling Tim Zowada's demonstration to your attention was that it demonstrated how a properly hardened piece of steel exhibits FAR LESS ability to break under stress (in fact, under far greater stress than an unhardened piece), thereby NOT deforming and providing a bent, useless knife. If the same knife could withstand the same stresses presented by your examples (like cutting roots and such) WITHOUT DEFORMATION, wouldn't that make it a superior knife?

I can fully understand your desire to compare your knife (and skills) with other knifemakers. It's the best way to know we're doing our best to make the best possible product for our efforts.

The reason that the ABS tests the way they do is NOT to prove that the knife is a superior product, but that you -as the tester- have the understanding of how the steel reacts to methods of treatment, and that you are capable of demonstrating these methods of treatment.

According to the ABS test guides:

“ 4. BENDING: THE PURPOSE OF THIS TEST IS TO SHOW THAT THE APPLICANT IS ABLE TO HEAT TREAT A KNIFE WITH A SOFT BACK AND A HARD EDGE.”

No mention here about it producing an inherently better knife, or even that the knife will be a better knife under certain conditions... just that the test proves that the applicant's ability and understanding are exemplified.

Please don't take this as a personal attack! I respect your desire, and envy your skills! I merely witnessed some things that changed my understanding and my outlook on the topic at hand, and I wish to share them! I shared the same vision you have not too long ago, and now I feel like the lights have been turned on.

I think you understand, because you are so active in posting here -- it's obviously your desire, too!

If you still feel this is just a difference of opinion, I'm cool with that, too. I hope we can still be friends!
 
MrPurple said:
If the same knife could withstand the same stresses presented by your examples (like cutting roots and such) WITHOUT DEFORMATION, wouldn't that make it a superior knife?
Click to expand...
In my own view,,,
What makes a superior knife would be one where the knife is able to be trusted and that you can use it in some nasty situations.

Lets look at "The Worst Case Scenario"
The worst case scenario would be to try to use a knife at my job, and then find that it snapped,,,,because chances are that if I try to really use a blade that "might" snap, well...it's going to.
Thats my luck.
If it "might" break, It will break,
And in the dark, in a sewer, or in places where you best not even think about whats in the water...

Thus the need I have in my own life, (and the reason i started to make my own blades in the first place) for a blade that will not break under torque.

so what have I learned after I did my test?
I learned that I can plunge into cutting situations where I can expect some risk to the blade.
And thats a big deal for me as such situations come up in my line of work about every day.

Knowing that my blade will not easly bend as my test sure proved to me, will help me trust myself as I think about doing some cutting.

Knowing that even if I push my blade to it's limits that it still will not break, means all the world to me.
Yes,its far better to know the facts about how your knife will react, then to find this out later when it's too late.

I can straighten out a bent knife blade with a hammer ,,,But I cant do much for a lost finger or eye.....
 
So when I think about it, What is a knife for anyway?

I think that a knife is for cutting other things.
Not yourself, that would be crazy.
But if I went out to build a knife that I felt deep down, "might" snap and cut me...well that would be crazy too.

Because with my luck, "Might snap in two" is that same as; "Oh you can bet it will snap in two".

I want my cutting edges to be sharp.
Everyone wants a sharp knife. Thats the point of owning a knife. Cutting things is the reason behind making a knife.

But what I also want is a knife that will allow me to use it without thinking about it's limits.
If I have to hold back torqueing on a knife because I fear the chance it might snap, my mind has drifted away from the job at hand...

Thinking about my hand and the risk it would be in just holding onto a breakable blade is a lot of trouble...
More trouble than it's worth if I can test a blade before hand and learn the blade can take whatever I can dish out at it.

The trick of a strong blade is that many times this is at odds with the idea of making a blade super hard so as to be super sharp.
My answer was to use a heat-treatment that hardens only the cutting edge.
The rest of the knife I would want to be about dead soft and very strong.
("Strong" meaning it will not break).
Im always interested in the ideas of others about how I can make my blades fulfiull the idea behind them.

The problem I have with types of steel or types of heat-treatments that make the full knife blade super hard, is that they always tell me "Yes" when I ask, "Is there a chance the blade could break when really torqued and pushed past it's limits?"

If I could learn how to make a blade that is super hard, and yet will not ever break, then that would be great.

But so far, I see knife making as walking on the edge between what you can get, and what you can't get away with....

This also is likely what the Japanese smiths started to use more than one steel in the katana.
I dont want to have to forge two totally different steels to get the the result I aim for,,,

But I still want what the Japanese smiths found, a very hard edge, with a very strong inner-spine.

What I aim for is a blade that is sharp
easy to sharpen
stays sharp in use
and is strong,
will not bend easy at all
and when pushed past it's limit, will bend rather than snap.

a blade that is not sharp is worthless to me
a blade that is not easy to sharpen is worthless to me
a blade that will not stay sharp in use if worthless
a blade that is not strong is worthless
a blade that can snap is worthless to me.
 
Definetly sounds like you're interested in a more Japanese style tempering/heat treatment. I have a katana and wakizashi that are exactly as you described, very strong spine and cutting edge, yet soft inner core that allows for flex and resilience. I've seen videos of them doing the same test you do, and the blade returns to true from a 90 degree bend over time.

The katana is made from 9260 spring steel (website says silicon alloy carbon steel). The wakizashi is 1045 carbon monosteel. The katana is more flexible since it's blade is much longer, the wakizashi is more rigid sicne it is shorter. I won't pretend to know alot about steel (because really I don't) so here is a copy paste from the site I purchased through...

"The 9260 is a silicon alloy which has a significantly increased fatigue resistance compared to standard 1060 carbon steel. The addition of 2% silicon changes the bahavior of the steel drastically for use in a katana. The use of 0.6% carbon allows this blade to be sturdy enough for tatami omote yet forgiving enough to resist dangerous chipping on rigid targets."

Not really sure where I'm going with this, your explanation of the ideal knife reminded me of this though.
 
I'm not seeing the grind type, thickness, or width of blade here. But from what I can see, the knife held up well. Congrats. Now with that said. For what I require of a knife that size, It bent far too easily. I want a blade that will just about rip the vice off the table. But that is just Me.
 
4W4K3 said:
Definetly sounds like you're interested in a more Japanese style tempering/heat treatment. .
Click to expand...
Yes, I think so too.
I do a little KENDO in my free time, and so Im around people who own swords.
As time goes on, I would like to learn how to make a real two-steel katana in the old-school manner.

I do think from my reading that the problems that I face in my search for the trustworthy working man's blade is much like the problems the Japanese smith faced seeking a great blade of war.

The reason I forge Ball Bearins right now is,
1- they are free from my work
2- they are more of a challenge that the leaf springs
3-They make an interesting story to tell
4-they seem to offer me the results that are close to what I am seeking from any steel.

Im not married to 52100 by any means, nor am I married to the heat-treatments I used on my test blade.
Im always interested in learning new tricks to use, new ways to HT steel, and new ideas about what steel might be better for my design needs.
 
mlovett said:
I'm not seeing the grind type,
thickness,
or width of blade here.
It bent far too easily..
Click to expand...

Grind type?.....I do a convex edge. The curve starts near or at the spine and goes in a curve all the way to the cutting edge.
The curve matches the natural effect you get from the slack-belt of my grinder between the platten and the contact wheel.


Width of blade?....Im in the house now, so this is just what I remember.
The "thickness" was at the spine around 1/4 inch thick, more or less...
The "width".at the widest part of the blade is over 1 inch...however the width gets a bit smaller as you go to the tang.

My idea for a cool looking knife is that I like a blade that starts out with a rather blunt point, and the width of the blade is biggest about 2 inches behind the point.
Then I like the cutting area curve to slowly go up a little as you move down the blade..

I like the look of that curve.,(if you log-on to Ed's forum you can see the curved design I love to make all the time at - http://knifetalkonline.com/smf/index.php?topic=42.0 )


It bent far too easily?....Perhaps, To tell the truth I didnt think it bent as easy as I wanted it to.
While I was bending it that first time I felt at the time that something was all wrong.
At the time it felt like it was not bending at all...and that instead it was going to snap on me.

This was only my very first Heat-treating bend test...Im sure in the future I will know more stuff and have different results.

I would like to see what you guys can do...
 
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