Cutting Coins

Ah the whole its there reasoning, something I can totally get behind :D Ive done enough wierd things myself because its there. My only gripe about extreme testing is when people apply it out of context. Certain things will do certain jobs well, while others wont. Its when we get our expectations wrapped around a certain set of results to apply to everything regardless of intended purpose that the whole testing thing becomes tainted for me. Meaning I dont mind if someone decides to attack a concrete slab with their khuk (hey its their money), its when they attack the slab and break their knife and complain about their knife is my main gripe. But I dont count coin cutting as too extreme a test, though going after a car with a knife/sword/machete/khuk/head, while a great stress relief;), in my books is.:eek:
 
there are certainly those who would misapply stress testing to other items. Like it doesn't tell me much that an AK-47 can survive being run over by a tank, because it's something the bearer of the weapon could not survive. I think an assault rifle should be durable, but small arms vs. a tank is unrealistic.

Also,` if you know a knive is left softer inn the tip, then expect it to fold or chip if you work it over. I have never had a tip failure in my tests, as the tempered area in the belly is where and what I cut with.

Keith
 
Pappy :

... some of the experiments you folks are talking about tell me next to nothing. Electric fence wire? Armor? Stainless steel knives cut in half? What the hell is the point in that?
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It is exactly to determine its meaning that you do it. The reason that I cut coins in the first place was because Rob Simonich was using it to promote the toughness of Talonite and since I had never done it, I had no way to guage if the performance was impressive or not.

As for what it means, well if you do it on multiple knives then you can extract more normal performance information. For example, if a knife dents up readily on a quarter and another doesn't it tells you that the edge on one is much stronger and this can be used to predict all kinds of performance and possibly steel characteristics.

Coins are really soft metal, as is most fence wire and such, a piece of hardened spring steel is much harder that these metals and should only take minor blunting. Bone, which is a very real consideration for a lot of khukuri application, is much harder to cut.


-Cliff
 
Hunting season is coming and I'll test a khuk or two on Deer or Elk bone. I'd hoped to do some penetration testing on animals..what with all the gut shot and car struck critters, the snake bit cows and what have you. But the other day I saw a dead deer and didn't even stop. By the time I rememmbered my plan the deer had swollen a size too big for my tastes. No penetration testing of gas bags, please.



munk
 
Originally posted by Pappy
I guess I am in Uncle Bills neighborhood when it comes to taking a chance on damaging my own property.
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Pappy-- you might want to take a look at the part about extreme testing at the end of this section on testing khukuris on the HI website. I think cutting a couple of coins is pretty mild compared to some of the stuff mentioned in the FAQ.

--Josh
 
So your khuk can cut a quarter, huh? Well, my khuk's four times tougher than yours; it can cut a dollar bill...
 
So your khuk can cut a quarter, huh? Well, my khuk's four times tougher than yours; it can cut a dollar bill...
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Another reason not to extreme test, it can get mighty mighty expensive:D
 
The real point is Cliff STamp goes places so we don't have to.

wish more manufacturers would test their stuff hard...

Pappy once opined that if you severe test a Khuk, he would never trust it the same..meaning a knife has some strenght in it, and you may 'use it up'. How many times could a Khuk be bent in the concrete test before you'd elect not to take it with you to Afganistan?

Don't ask me. I don't know metal or knives. I don't.



munk
 
That is a good point about testing which damages a knife, you basically know after breaking it that it would have been a good one to depend on, these are tests like bending it until it breaks, or takes a set. These are tests that a maker / manufacturer should do, and are frequently used as QC checks. You just pick blades at random from each run and make sure they break where they are supposed to.

For the user, you can't go this far and have a workable blade left so most people don't do them for good reason. However hard edge impacts and such don't leave the blade with that much damage. Because spring steel is so tough, and the blade is only selectively hardned, the cracks won't propogate up very far and thus even if you really beat on the edge, the blade as a whole won't snap in half later on.

One thing I would suggest to anyone who is interested in performance of this nature is to buy a few really cheap "made in taiwan" (or whatever) knives. Test these to destruction and use this as a lower limit. There is obviously no need to tolerate anything lower than this, and a decent khukuri should blow past all that testing without any significant damage.

-Cliff
 
If your blade might have to save your life either in combat or the field I'd strongly suggest severe testing before the fact. Would you take a gun into the same situation without putting numerous rounds thru it? Just good common sense.
 
well, yeah, but I wouldn't want to put a hundred severe overloads through it..

a balance here, Bill? In your experience of bending blades, you havne't had problems with the ones so bent later on, have you? I'm guessing.

munk
 
I've never been able to bend a khukuri blade without the help of a long pipe and that's like shooting overloads thru your gun. How much overload does it take to make it blow up?
 
If it is a mauser action, one hell of an overload. Im not sure it can be done with a sngle round. the design is foolproof.

munk
 
Originally posted by munk
If it is a mauser action, one hell of an overload. Im not sure it can be done with a sngle round. the design is foolproof.

munk
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If you ever come across volume 2 of 'Handbook For Shooters & Reloaders' by the immortal P O Ackley, take a look at chapters 1 and 2; "Strength of Military Actions" and "A Few Causes Of Blowups". There's a picture of a Springfield (ie Mauser) action, wrecked by an overload, that'll make you reconsider. According to Ackley (who should know) it's alarmingly easy to scrag any rifle through a moment's carelessness.

That said; many years ago a friend of mine (motivated purely by scientific curiosity, you understand) tried a series of experiments to blow up a side-by-side shotgun. The gun in question was a cheap Belgian rattletrap, external hammers, over 100 years old, black powder proof only, that had been condemned as unsafe to use; its (Damascus) barrels were paper thin and pitted, the action was off the face, and nobody in his right mind would even consider shooting the thing from the shoulder.

Would that old beast blow up? Would it heck. 3" magnums in both chambers, a foot of mud in each muzzle - no effect. A massive overload of nitro powder, two ounces of shot, three 10-bore wads hammered halfway down each tube, and then driving the gun 12 inches into the ground with a sledgehammer - one tug on the string and the gun went up in the air like a rocket, came down and smashed the stock, but barrel & actions unaffected. Finally, some time later, since night was closing in and the experimenters had homes to go to, someone suggested using black powder instead of nitro, having seen pix of massive muzzleloader tubes mangled by short-started loads. Several attempts later, with a charge in excess of 150 grains of black powder and a *steel* interference-fit plug hammered halfway down the bore, the old warhorse blew - interestingly, *lower down* the tube (ie towards the muzzle) than where the plug had been seated.

By the time it finally expired, the experimenters had lost count of how many viciously abusive charges had been loosed off through that fine old gun; and it's worth mentioning that most of the tests involved a simultaneous double discharge (ie both triggers pulled at once); and that although the right barrel blew under the combined effects of black powder and steel plug, the left barrel shot out the plug without any perceptible damage; and the action appeared to be as good at the end as it had at the beginning.

My friend's comment at the end; "If I'd known it was that good, I'd have kept the f** thing..."
 
Perhaps I shouldn't have said, foolproof, though it is still difficult to imagine a single round blowing the action.

The Springfields are not exactly replica mausers, having some design changes. They are weaker, and in fact, are part of the reason Saami sets a 49000 cup limit on the 30.06..or whatever the precise number is, it is not up to the 52,000 to 55 of todays cartridges. YOu are right, though, in that anything can be blown. I've read Ackley. The Mauser is arguably still the strongest bolt action on the market and the safest. More than an overload, you might be referring to a blocked barrel path and locking lugs that are worn or not locked. I'm sure there are many other things I am not aware of. Chambering the wrong cartridge usually just results in a mess, not a blown action.
What he says about wildcats cartridges is still true today.

I had an engineer friend who tried to blow up a H&R single shot. They ended up welding the barrel shut before it would blow, and standing behind a concrete wall when it fired.

edit; to give you an idea of what they went through, they kept rechambering the rifle to larger cartridges, finally the 460 Weatherby....
munk
 
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