hard testing

E

Eric_425

Joined
Sep 21, 2002
Messages
460
It's probably paranoia, but seeing the thread about the bent sirupati... I've come to think I haven't really tested my knife under any sort of demanding condition. I looked at the testing thing under the FAQs on the HI site. I've also looked into some stuff from other manufacturers like Busse and swamp rat, as well as a few Cliff Stamp reviews. Lateral flexing for sure. Probably according to HI's specs, I'll put it in a padded vice and put weight into it. I don't expect any damage though, since this is a THICK piece of steel. To test edge strength and retention, HI's site also talks about chopping nails, and SR/Busse/Cliff reviews have shown tests which involve chopping concrete, with dulling and scratches. Which tests should I duplicate? And what results should I expect?
 
I've cut through coins before with an 18" AK with no damage. That was more for fun than anything though. If you want to test the blade, do some heavy chopping with it. Make sure nobody else is around if the blade should fail, find a big stump, and chop the hell out of it. To a lesser extent, you can give the khuk a few whacks on the stump with the flats to see if it's ok. Wedge it into something and push on it to test the lateral strength. I guess what tests you choose to employ will depend in part on what you plan to use your khukuri for. If you plan on chopping up a lot of concrete blocks, maybe you'd better chop a few to see how it holds up.
 
I would not consider chopping nails or concrete as a way to "test" your khurk. I have used nail chopping and chopping a mild steel bar as a way to test a steel to see if I wanted to make knives out of it. I did not use the test as a way to find out if knife "A" could chop nails I wanted a general test of the steel. Cut some hard wood, give it a good bend side to side but you should not consider it a failure for a blade made to cut wood to chip or break if you use it to cut things like concrete. I think that many of H.I. products could pass any crazy test that we could come up with but that does not mean that we should expect it to be invulnerable. Just my thoughts.
 
Go to the local hardward store, buy some pressure-treated 2x4s (cheap) and beat the heck out of them. Then, kindly recycle the wood....no harm done to the forest. :D



[edited to add]
If you can find the "pink" kind...they are super tough. They use them in cutting competitions for the ABS now because the guys were going through the regular 2x4s too fast....now it takes 4 times as long to cut - even for the fastest/sharpest of the bunch.
 
I'd go for some sort of oak, dried maple or pine, the actual tree limb sort. I mean really go for it. A 2x4 might show if you had a very weak blade, but the weak ones I have had would easily chop a 2x4 without problems.
 
Chop wood, dead hardwood. You have to do enough natural activity with it (chop wood, separate wood when needed, etc) that you know you can rely on it. Anything past that is your call.

IMHO, you can take any blade to failure if you keep trying. It's a matter of what is acceptable and what isn't. What job do you want it to do in what environment?

I used a Hanuman for a long time in the woods and never had a problem with it. I also wasn't trying to create unnecessary problems for it. I just wanted to be able to use it to survive, make tools and keep me warm with firewood.

Above all, no matter what kind of test you want to do, safety first.

All that being said, Josh, I never heard of cutting coins before. That's a new one.
 
I cut through some nails but that wasn't on purpose. There happened to be nails in the fenceposts that I didn't notice. Some prying too, when breaking up some old furniture (a '65 VW isn't conducive to trips to the dump). I wouldn't chop a cinderblock on purpose, though. Just my two bits.

Frank
 
I'm obviously not going to be cutting concrete or nails on a regular basis... but I want to see what the blade will handle, if the situation will ever arise. I'm kind of iffy on wood testing. I mean, pretty much any fixed blade would handle something like that, right? The sirupati with the supposedly bad heat treat also got tested by chopping hard at wood, but did fine until the blade bent and cracked on a prying application. I'm thinking I need to try something harder, to really test the tempering of the steel at the edge? I expect a little damage to occur, scratches and dulling, but nothing that can't be taken care off by burnishing and sharpening? If the blade is going to fail, I'd want to know now and not when I'm out in the woods. Testing beyond the typical use of the blade, to know a safety margin for when it's actually out in the field. I wouldn't want the typical, daily use to be right at the limit of the blade's capability... does that make sense?
 
Eric_425 said:
... does that make sense?
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Yes. That's why you want to hit something solid like a heavy piece of hardwood with each side and the spine of your khuk several times. Then chop into a heavy piece at the end and try to split the wood by pushing and pulling from each side or twisting the blade in the wood if you have the strength.
I mentioned it before about Uncle Bill once having a pic of him trying to bend an AK in the center of one of those huge wire spools.
You dan't want too get carried away and do something stupid with your khuk as obviously a Sirupati isn't going to withstand the same force that you could apply to a heavier blade.
 
If I didn't respect the tool too much, I'd try to destroy my chiruwa AK just to let it laugh at me...but I do.

The idea of testing is to make sure it is up to it's intended use...and I have seen wood choppers, cutters, slicers and other such blades from HI. I never saw any promoted for chopping cinder blocks...just a few folks who did it just to see where a breaking point was for a particular blade.

Wow...it'd be like taking my Chevy truck up progressively steeper hills to see at what point it would tip over backward.

Actually, *that* sounds like fun too...
 
If the edge is really hard, I'd expect it to fail when you hit something hard as concrete or nails. Frankly, I would expect a pretty bad fracture, and loss of the sharp edge if you hit really hard stuff with hard steel.
Knives are not made to cut steel. You have a hacksaw for that.
I would use a hammer and cold chisel for concrete.
 
It's an AK bowie. Chopping wood is something I'd do on a regular basis, it's day to day activity, so I wouldn't really consider chopping more wood as a "hard use" sort of test. Even the siru had been used to chop wood, and it didn't reveal the potential problem until it occured. That's why I think it should be subjected to some test that goes beyond it's day to day activity, to know how it'd perform under demanding circumstances. I think chopping a cinder block is done by other manufacturers to see how the knife would hold up when you get a bad or missed cut and end up hitting a stone out in the woods. Chopping nails is one of the tests demonstrated in HI's FAQ's.
 
Eric,

if it's an AK bowie then i would suggest a couple of things:
1) don't chop nails with it. Will it survive it? oh yes, very well indeed. Will it require extensive sharpening to repair? you betcha. AKBs generally have pretty thin edges that will roll or dent when you hit metal...but not chip.
2) don't stab into a piece of wood and torque it sideways a la cold steel 'Proof" the tip is designed to bend on the AKB so that they won't snap off at the worst possible moment...a la cold steel.
3) Do bury the edge deep into a stump and give the knife a few strong but CAREFUL pulls in each direction.
4) stick it in a vice and give it some full force pulls.
5) put on some leather gloves and a padded long sleeve shirt and wack the bejeezus out of it on it's flats.
6) chop and torque and just generally use bad form to work your way through a couple 5-6" logs.

If done correctly, testing can be completed in 15 mins. You should be dead tired and should feel fairly foolish for even thinking that you could defeat the mighty AKB:)

just my humble opinion, though.
Jake
 
Hard wood or nasty resin soaked pine.
My standard test is to swing as hard as I can- or as if I'm going to pass right through the wood. I don't like doing it because I fear I'll chip the blade. But it must be done. It is not standard cutting, though. It is deliberate and inefficient abuse- a proof load.

<<<I've cut through coins before with an 18" AK with no damage. That was more for fun than anything though>> Josh

As we've known for a long time now, Josh enjoys commiting petty felonies in the privacy of his own home. And that psycho tropic cactus in his front yard? The latest satellite photos show a large bite missing from one of the trunks. It also appears someone put green paint on the gap to fool the eye.

munk
 
munk said:
Hard wood or nasty resin soaked pine.
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Why do *I* always have to be the one resin soaking the pine? Maybe some of the other guys would like a chance to do it for a while!!! :mad:



;)
 
munk said:
Hard wood or nasty resin soaked pine.
<<<I've cut through coins before with an 18" AK with no damage. That was more for fun than anything though>> Josh

As we've known for a long time now, Josh enjoys commiting petty felonies in the privacy of his own home. And that psycho tropic cactus in his front yard? The latest satellite photos show a large bite missing from one of the trunks. It also appears someone put green paint on the gap to fool the eye.

munk
Click to expand...

Haha, if you guys only knew. On top of it all, I fear I might be a Thoughtcriminal as well. It'll be Room 101 for me one of these days.
 
munk said:
Hard wood or nasty resin soaked pine.
My standard test is to swing as hard as I can- or as if I'm going to pass right through the wood. I don't like doing it because I fear I'll chip the blade. But it must be done. It is not standard cutting, though. It is deliberate and inefficient abuse- a proof load.
munk
Click to expand...

That's exactly how I do it.


The only 2 HI blades I have ever rolled were my first Ganga Ram on a downed oak that was real dry, and an AK bowie on a pine that was super resinous as Munk mentions. Both I managed to straighten back out, but I have had others with even thinner edges that survived, but yeah get it down in that notch and slam it!
 
I bent the edge on my first YCS.....that's actually what gave me the guts to start putting convex edges on my khukuris. And the rest is history. ;)
 
Dan, that's probably because just as you'd entered the forum, and myself several months later, the Maoist uprising was happening and HI not only had a run of very thin edges but some blade failures as well. Yvsa was in the background, always saying, 'convex, convex." (not that I understood what that mean then.)

Anyway, I think for those of us around then and witnessing the failures, the point was made in a way it could not have been otherwise.



munk
 
Yeah....technically it was supposed to be the "Last of the YCS". Quality control was a big issue - Uncle had me take it off the store permanently. Sad day......I would love to see it as a regular item.

Honestly, though, I think it was too much work for regular kamis....they want the knives to be done fast and these just take too much time.



(If you do a search on it, you can find it. ;) )
 
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