Cracks at the cho: PICTURES ON Pg 3

SkagSig40 said:
It was talked about above that there are tests that can be done to see what the "cracks" are.
Click to expand...

The knife would not end up as sent....at minimum the area would need be taken to smooth fresh metal, and then harmless (if removed) dye penetrant and developer sprayed on and then examined....the dye pen might not even be needed if an actual crack were detected after cleaning and smoothing........it might not be to your liking to do that to an old favorite as area would always stand out to you.
...and i wanted to say how sorry i was to hear of health issues forcing sales of knives as i know all about that, and here i was jumping up and down on you......

Personally, i think you just need to hold onto those favorites and if an actual issue, some newer examples are bound to turn up for examination...
 
Moonw said:
Would cracks in the original leaf springs caught earlier? I know they are inspected, and I am sure the visual acuity / assessment of someone doing this for living would be nearly always accurate. But, even if I throw this into discussion, it would still not account for a huge number of issues. I mean, repeatedly missing cracks. Or maybe through forging. If tiny, these would go away...I am just thinking out loud. I suspect hammering hot iron would "pack" them, unless air is trapped, which would be bad?

I am still relieved, seeing that the original poster has good intentions, and I agree that such marks would make me look twice and thrice at a knife. But they are most likely not cracks.
Click to expand...

Hahahaha....ok, just when it seems settled chos are at least started with forging, here again under my own nose proof that the only universal constant is change.....my Tarwar smith hard at work on somebody else's or maybe mine own next knife....and no cho when blade about finished....

 
SkagSig40, Not experiencing what you have in person, please take my comments as you see fit. I have never experienced steel or iron "tearing" while being forged out. Wrought iron is not being considered here. I have experienced what one might possibly term "tearing" when punching rivet holes in the tang. When this has happened, the metal has been thin, less than 1/4 inch thick. Usually old buzz saw blades that someone has brought over. I will not say that what you are seeing are cracks, but it is possible that if your chos were punched out, as most of mine were, there could be tiny "cracks" on the downward side of the blade caused when the slug shears free of the slightly cooled metal. If so, I don't believe the cracks could go anywhere unless you were using the khuk as a froe and giving it a mis-lick with your maul. Not a common occurrence, but there's always that one time possibility when dealing with the law of averages.

I have had blades crack upon being quenched whether it be in water, brine, or used motor oil. Again, it has been due to the metal's characteristics, such as age, composition, thickness, and etc. My personal opinion is that if this were the cause of your particular "cracks", you would have no trouble seeing them and more than likely, in multiplicity. My bottom line is that I do not believe that you have anything to worry about and that you and all your khukuri are going to be just fine.

I, for one, am glad you brought this subject up as it has a great plus side: It has obviously made several of us examine our blades rather minutely and the end result appears that we all have reconfirmed HI's high quality standard.
 
Ok I found a crack too :) But this is NOT a HI Kuk :D (Seriously, it's not)
CrackedCho2.jpg

Full size URL
http://images59.fotki.com/v255/fileq6nF/15eb7/2/1343482/9537974/CrackedCho2.jpg

As you can see on this example, the Cho is no clean cut. Speaking of clean, I used a Q-Tips to remove the protective grease and I ended up with Q-Tips hairs all over.
 
mtngunr said:
The knife would not end up as sent....at minimum the area would need be taken to smooth fresh metal, and then harmless (if removed) dye penetrant and developer sprayed on and then examined....the dye pen might not even be needed if an actual crack were detected after cleaning and smoothing........it might not be to your liking to do that to an old favorite as area would always stand out to you.
...and i wanted to say how sorry i was to hear of health issues forcing sales of knives as i know all about that, and here i was jumping up and down on you......

Personally, i think you just need to hold onto those favorites and if an actual issue, some newer examples are bound to turn up for examination...
Click to expand...

It is no problem at all man! I'm overall pretty healthy and with a little luck I'll be back at work soon! I just tore my Achilles and lower calf to heck and the reconstructive surgery has been a long hard road but getting better daily now. Sold knives and guns to help pay medical and missed work income.

Being off work has given me time to play on the net and now I'm getting the desire to collect khuks again. I'll come across another one with a perfect example and I'll send it to you to test. Maybe we can get to the bottom of this and it will be a learning experience for the entire forum!

Again no harm no foul! :)
 
Last edited by a moderator:
snowwolf said:
Ok I found a crack too :) But this is NOT a HI Kuk :D (Seriously, it's not)
CrackedCho2.jpg

Full size URL
http://images59.fotki.com/v255/fileq6nF/15eb7/2/1343482/9537974/CrackedCho2.jpg

As you can see on this example, the Cho is no clean cut. Speaking of clean, I used a Q-Tips to remove the protective grease and I ended up with Q-Tips hairs all over.
Click to expand...

This is EXACTLY what a lot of mine look like except it does not curve at all. It just goes up mostly and right from the corner.

EDIT TO ADD: I'd take a dermal and clean that cho up. Looks like a lot of slag is still on there.
 
snowwolf said:
Ok I found a crack too :)
.

As you can see on this example, the Cho is no clean cut. Speaking of clean, I used a Q-Tips to remove the protective grease and I ended up with Q-Tips hairs all over.
Click to expand...

this cho appears to be stamped out poorly with a.cookie cutter die, and outline visible where punch failed to cut cleanly or at all.....
 
My last is rougher, and again, i have always been rather amazed that every single khukuri in the world does not break in half right there, every time they are leaned on in any way.....and the rougher, the more prone.....

But they generally do not, and generally no problem at all.....what i do NOT expect are only nearly invisible cracks which go nowhere....

To my eyes these last two HI chos appear completely file worked....clean sharp edges and all....
 
mtngunr said:
Hahahaha....ok, just when it seems settled chos are at least started with forging, here again under my own nose proof that the only universal constant is change.....my Tarwar smith hard at work on somebody else's or maybe mine own next knife....and no cho when blade about finished....

Click to expand...

Good catch.
 
I expect there is a great amount of latitude in how these knives are made so long as knives meet quality standards, and kamis do most certainly get an earful if anything they do turns out not to be up to HI standards.....HI is not a "not invented here" company and responds immediately as possible to customer input.....heck, just look at the wild line of knives up for sale!.....and dearest Yangdu totally understands how important quality perceptions are to the health of the company...
 
snowwolf said:
That's how I read them too.

The Cho is in the softer area of the blade and less susceptible to break.
Kukri working edge: http://www.bladeforums.com/forums/showthread.php/720287-(WiP)-A-kukri-s-quot-working-edges-quot
Click to expand...

Just as an fyi, on things such as turbine blades, aircraft propellors, etc., cracks are not ok at all......a blade under centrifugal force is awesome in destructive power if it fails...and those blades are not taken to high hardness values either, to minimize chances of cracks....but no crack is considered "safe"....any suspect crack is "blended"/smoothed/radiused away until gone and if amount of metal removed is still within specified limits, the assembly is rebalanced relative to other blades (ie balancing your car tire but via matching weights of blades on a turbine or adding weights on a prop), and then tested and put back into service....but they are never ignored.

And neither are they normally subject to high impact stresses as a matter of course....this is all to say, again, for safety's sake, if anyone ever suspects any sort of crack, deal with it immediately via blending if not concerned enough to think it a warranty issue from ANY knifemaker....this also goes for nicks and notches in blades....there is not one of them a safe condition.

Edited in PS....am 99.999% sure these exact sentiments are echoed somewhere on this site under an official safety thread or statement.
 
Last edited:
mtngunr said:
Hahahaha....ok, just when it seems settled chos are at least started with forging, here again under my own nose proof that the only universal constant is change.....my Tarwar smith hard at work on somebody else's or maybe mine own next knife....and no cho when blade about finished....

Click to expand...

Maybe I'm misreading the photo, but it looks to me like the kami is about to pound on cold steel, which suggests that this is a posed picture. Also, the handle doesn't seem to be fully shaped yet.

So maybe he's going to heat up the handle and cho area (after the photographer goes away) and put in the cho at that point. He might have done things out of order and put on the edge first so that the blade looks more finished than it really is. I'm betting that it isn't edge-hardened yet.

That's the trouble with still photos. Like taking a still photo of a bird and wondering how it manages to fly.
 
It is a still (accessible on this page) from a video (i believe) and the steel is quite hot, and in midstrike impact, operational forge to right and glowing...color depends on light...the kamis all did a bit of ceremonial pounding at the big celebration of new shop opening...it is not nor was ever represented to be a normal workday shot....observe the anvil freshly blessed...
 
Last edited:
mtngunr said:
this also goes for nicks and notches in blades....there is not one of them a safe condition.
Click to expand...
Chips and nicks are a different category than actual cracks, to use te Japanese example regarding swords-nicks and chips were generally no polished all the way out on fighting swords, unless they passed all the way through the hamon into the softer body of the blade (in which case that blade was retired or made into something else). No sense removing valuable hardened edge when it'll be gone in a couple of polishes/sharpenings.
I think a lot of us on the HI forum echo this regarding dings and chips-especially on a blade 3/8" or 7/16" thick, there's not much going to let gofrom a nick that wasn't going to let go anyway. Now I have been known to sharpen out chips that were just wacking me out, but that's different...
Now cracks (as opposed to little cold shuts from forging) I'm with you 100%. Same with defects on (closest analogy to propellers) lawnmower/bush hog blades- if it's cracked or has a huge ding that can't be gotten rid of, buhbye...shrapnel bad. Shins good. :D
 
Well for sure i was probably more thinking of normal heat treated knife blades and sizes when i just had to add the chips and dings thing, and unspoken/unwritten was also thinking huge more notching chips/nicks when i was applying to the huge HI blades, not minor edge damage and i was guilty of very poor choice of words. Rest assured we do not blend out every single ding on turbine or prop blade as soon as it happens. But we DO have regular inspection of same and you might notice a small plane pilot who knows his stuff runs a hand down prop before a flight....looking for the whopper which might mean a thrown blade and then engine ripping free of front of plane a micro second later....there are limits.

To me, a sword whirling in an arc around a central point is no different and props and turbines and mower blades are not normally expected to survive coming to a crashing stop against a fixed and immovable object, so i do not tolerate a sharp edged/cornered notch, and it will be blended out locally to leave a radius....my arm or my head or leg if a blade snaps and rebounds, and i had one recently of another make/model fly past my head on rebound when it failed when new....it is a shame we actually have no standard to go by but only personal feelings such as yours and mine......in the aircraft and power generation industry there have been extensive collations of data from deadly failures over 100 yrs so NORMALLY we have an idea of what is "ok"......but even headlines showing a disaster involved aircraft had just been inspected shows we are not right all the time....just most.

...i do not know what manner of damage any ancient warrior found acceptable on his expensive and hard to find battle blade, but legends and ancient histories are full enough of mention of broken blades that it seems they often estimated wrong....and i agree swords would have a short service life when cleaned up immaculate and so did not happen....and many a warrior of old also had a short service life.
 
Last edited:
Many nicks and other damages were simply tolerated due to not only the expense of replacement, but simple logistics. You simply get what you can when you can.
 
Absolutely.....most armies had smiths and portable forges but your average foot soldier fought with what he had....not with what he wished he had....
 
You must log in or register to reply here.
Back
Top