Why there should be no more tang failures.

Bill Martino

Bill Martino

Joined
Mar 5, 1999
Messages
34,096
My ucler has been activated because of these tang failures. I have been wracking my brain trying to figure out a good fix. And yesterday it hit me.

I was thinking about the entire manufacturing process and I suddenly realized that I had never seen a kami test a tang -- nor had I ever even heard of it! Maybe some do but I am not aware of it.

Think about this. The kami forges the blade and tang and gets it to the point where it is time to harden the blade. He hardens it and tests the BLADE for hardness. He never tests the tang! Then he puts the handle on the knife, edges and finishes it up. This is standard procedure all over Nepal and in both shop 1 and 2.

I called and got Gelbu on the phone and asked if tangs were tested. Reply no. So, now a testing procedure is being implemented. Henceforth the tangs will be hammer and bend tested after hardening and before handle is mounted. Problem solved!

Upon relection I wonder why the kamis do not test tangs. They know that 1 in a thousand will fail so my guess is they must figure that this small number does not merit a test. I just don't know. But it seems very strange and puzzling to me. I guess it is just one of the mysteries of the Orient.

Now, how can I get this information to every village kami in Nepal? If I am successful I may become known as the white monkey who changed the centuries old khukuri manufacturing method (or at least QC method) in Nepal.

Namaste!

Uncle Bill
 
Uncle Bill- Does that mean we address you as "The White Monkey" or just plain old "Uncle Bill"?
 
I was thinking of something similar; is there something that can be done to minimize the impact of manufacturing variation on the design ? One can make a change in the fabrication proces, testing process, design, or any combination thereof. The short term solution of sorting by testing seems ok, but the fact that the problem happened suggests that as you've noted some other improvements might need to be implemented.

Often a problem like this opens up an avenue for some more development and hopefully improvement, and as long as one can afford to do it such development is the most interesting work that one can do in a manufacturing environment.
 

If we have any MBA candidates out there this would be a great thesis - Distributed Rural Continuous Process Improvement Procedures
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Namaste,
Jeff Paulsen
 
And maybe get a grant to study and implement the KUKRI (katmandu urgent khukuri rural improvement) program :^) It should start with a two year trip to Nepal, to visit as many kamis as possible.
 
In Nepal I was often referred to as the "White Monkey." I didn't mind.

We set into effect in shop 2 a larger tang and I asked for a radius rather than the square cut. We will see. Sometimes the kamis resist any change to a centuries old design. However, they are not adverse to spending a couple of minutes to bang the tang with a hammer and try to bend it. I will have much more success with the testing than a design change. But I have tried both.

I like the idea of the KUKRI project. I have seen many with much less merit.

Namaste!

Uncle Bill aka "quiri bandar" (white monkey)

 
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That will be the permanent fix.
Great idea Uncle.

There was only a 'big deal'about all of this with Uncle Bill.
I doubt any other manufacturer of anything has had so few failures.
Considering the working conditions and methods of manufaturing that are used to get our precious Kuhkuri's to us. It is absolutly unthinkable that there has been so very few that has caused a problem.

I don't think anyone else in the world could make these knives so consistently perfect using the finest in new materials and testing procedures.If anyone was able to do it then we wouldn't be able to afford them.These Kukkuris are more than bargains at the regular price!!!!

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>>>>---¥vsa---->®
The civilized man sleeps behind locked doors in the city while the naked savage sleeps (with a knife) in a open hut in the jungle.

 
Thanks, Yvsa. At least I won't wake up because of dreams of tang failure if they start the bang the tang amd bend the tang test procedure. Whether they will change the design I'll have to wait and see. As I mentioned the kamis do not take kindly to a white monkey telling them how to design a khukuri.

Uncle Bill
 
I am an ignorant white monkey with no experience in bladesmithing, but I wonder if there are reasons the design has evolved the way it has.

--Maybe-- the kamis prefer to keep sharp angles on the blade/tang juncture to help ensure a crisp lock for the handle? (i.e. no round corners so that there is no possibility of handles twisting or sliding and stuff?)

Granted, I am just talking out of my a** here, so you should all feel free to ignore, ridicule, or otherwise laugh at my speculating.
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Namaste!

-Dave

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"Smooth Bastard..."
 
I am sure the kamis have a reason for doing it as they do. Putting a radius on the top of the tang is no problem for them but they don't do it. I am not sure I'll get them to change but the tang testing procedure is underway in shop 2 and will be in shop 1 as soon as the message gets there.

Uncle Bill
 
Dave K, I think you hit the nail on the head.
Was rereading an old "Blade" magazine article on tangs, and the Sheffield cutlers used a square tang for exactly that reason, to prevent twisting and loosening.

I know the kamis don't like "panna buttas". Given their tools and resources, no wonder. But over here, with modern epoxy and drills to put in pins, I don't see why 1) just bending the tip of the tang's tail into an L shape, 2) notching the tang in several places, or 3) drilling and pinning w/ 1/8th or 3/32nd brass rod thru bolster and tang tail ( maybe bending tail into an eye and pin thru eye ) and just filling the handle up with epoxy wouldn't be just as permanent as tang thru the buttcap and mushroomed. I may try something like that on the villager I'm sprucing up.
 
Rusty, it's a good idea. I asked why they couldn't drill a 1/8 inch hole and pin thru the existing tang. They said, "we never have." And that was the end of that story.

Uncle Bill

[This message has been edited by Bill Martino (edited 20 August 1999).]
 
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