Another Blackbird down(updated-got replacement)

I don't know why it broke. I would have to see it and know more about how it was used. However I thought it was meant as a "survival" knife. I would think it would be stronger.
 
Maniacal Pete said:
There's a sometimes unexpected bit of physics that occurs in a flash when you hit a small branch with a knife,
that causes it to to snap back and grab the blade with a great deal of force.
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Aye - especially if you are not putting force on the branch with your off hand.
 
liamstrain said:
Aye - especially if you are not putting force on the branch with your off hand.
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I've got a phobia grabbing branches n chopping after almost chopping my finger off, doing just that. Blade was too dull and skipped over. To the bone, not through
 
With tension cutting, it's not so much chopping as it is a push cut...which helps minimize those kinds of accidents.
 
Maniacal Pete said:
There's a sometimes unexpected bit of physics that occurs in a flash when you hit a small branch with a knife,
that causes it to to snap back and grab the blade with a great deal of force.
Click to expand...

Yes, this is inline with my thoughts.
 
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This whole "don't chop small sticks" thing has been discussed here before, and with the overall conclusion being that it's complete BS.
http://www.bladeforums.com/forums/showthread.php/980561-What-can-you-fairly-expect-a-knife-to-do
Do you guys honestly believe that something like that could cause such a catastrophic failure in any modern, well heat treated steel? It's ridiculous. 154CM isn't as tough as something like 5160, but it won't shatter like glass any time moderate force is applied. The knife obviously has a heat treat issue. (And this isn't the first time something like this has happened with the Blackbird, either.) As someone said in the thread I linked to, it's a safe bet that a five dollar kitchen knife wouldn't have taken the damage that this knife did.
 
Dan57 said:
This whole "don't chop small sticks" thing has been discussed here before, and with the overall conclusion being that it's complete BS.
http://www.bladeforums.com/forums/showthread.php/980561-What-can-you-fairly-expect-a-knife-to-do
Do you guys honestly believe that something like that could cause such a catastrophic failure in any modern, well heat treated steel? It's ridiculous. 154CM isn't as tough as something like 5160, but it won't shatter like glass any time moderate force is applied. The knife obviously has a heat treat issue. (And this isn't the first time something like this has happened with the Blackbird, either.) As someone said in the thread I linked to, it's a safe bet that a five dollar kitchen knife wouldn't have taken the damage that this knife did.
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Dan 57
It's about geometry and not heat-treatment!

Regards
Mikael
 
It's about both. But in this case, unless the knife was ground paper-thin half an inch behind the edge, the problem is with the heat treat.
 
It broke. Ipso facto bad heat treat? Not much control for all the probable variables.

From the pictures, the blade did not "shatter." Half-moon pieces broke out.

If you had your choice of all commercially available steel, who would deliberately select 154 to resist lateral loading of the edge of a knife? 1/8" FF = pretty thin in that last 1/2"
 
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Heat treat seems to be the most probable cause, especially seeing as the Blackbirds have had HT problems in the past.
"Shatter" was a hyperbole.
154CM isn't a particularly strong steel, but it isn't weak, either. It should've handled this no problem. (And I still haven't seen any evidence as to this whole "lateral load on edge" thing.)
 
Dan57 said:
Heat treat seems to be the most probable cause, especially seeing as the Blackbirds have had HT problems in the past.
"Shatter" was a hyperbole.
154CM isn't a particularly strong steel, but it isn't weak, either. It should've handled this no problem. (And I still haven't seen any evidence as to this whole "lateral load on edge" thing.)
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This. I'm going to stick my neck out and call this a genuine case of bad heat treatment. I've seen Benchmades in 154CM with tips that got bent from abuse--they didn't break. Let's face it, Ontario isn't known for having the most consistent heat treatment. Yes it's 154CM, and yes it's a FFG knife, but that doesn't mean that it's a design flaw. I think it's an execution flaw, especially given the track record of the company, and the knife specifically.
 
Dan57 said:
Heat treat seems to be the most probable cause, especially seeing as the Blackbirds have had HT problems in the past.
"Shatter" was a hyperbole.
154CM isn't a particularly strong steel, but it isn't weak, either. It should've handled this no problem. (And I still haven't seen any evidence as to this whole "lateral load on edge" thing.)
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What "evidence" - one way or the other? He was chopping branches on a tree and they were small. That is so unspecific as to provide no basis for reasoned analysis. Dead/live? If dead, dry or wet? Oak/poplar/hickory? Did they or did they not bend when struck? How deeply imbedded was the blade when the two pieces broke out? What WAS the RC of the blade in the two places where pieces chipped out?

No need to explain hyperbole. I saw the "reviews" of this knife. 0___0 Finest survival knife ever made. (the 1932nd "finest" this year [hyperbole]) Apparently made of finest unobtanium masquerading as CM154..

We have seen one other break in an entirely different place (about where that 1/4" thick Cold Steel famously broke) and not when chopping - much less branches on a tree that may have moved while being chopped.

I am not saying you're wrong. I do believe there is insufficient evidence (to use a word) to come to any firm conclusion.
 
Sonnydaze said:
Good factory customer service means that they will stand behind their product. No sweat, friend.
Sonnydaze
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Called ontario knife co. They would be glad to replace it(after examination), basically send a new one scales and all. I sent it out today as well, so I will find out what they decide in a couple weeks or hopefully less. Cool beans!
 
Thomas Linton said:
What "evidence" - one way or the other? He was chopping branches on a tree and they were small. That is so unspecific as to provide no basis for reasoned analysis. Dead/live? If dead, dry or wet? Oak/poplar/hickory? Did they or did they not bend when struck? How deeply imbedded was the blade when the two pieces broke out? What WAS the RC of the blade in the two places where pieces chipped out?

No need to explain hyperbole. I saw the "reviews" of this knife. 0___0 Finest survival knife ever made. (the 1932nd "finest" this year [hyperbole]) Apparently made of finest unobtanium masquerading as CM154..

We have seen one other break in an entirely different place (about where that 1/4" thick Cold Steel famously broke) and not when chopping - much less branches on a tree that may have moved while being chopped.

I am not saying you're wrong. I do believe there is insufficient evidence (to use a word) to come to any firm conclusion.
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Between light to moderate chopping and batoning during its life. Only trees its seen were alder and spruce. We have some cedar, but I don't recall cutting any. The branches that did the damage were on a dead fallen spruce(damp too). At the base of the branches(where it was damaged) they didn't bend much. Could've been technique, could have been weakened from the cold weather, who knows/who cares. It's all up to OKC now
 
Fourtytwoblades,
Who, of the mass producers, do you think has a consistently executed HT?
Just wondered what you thought..
 
Tbaggin said:
Fourtytwoblades,
Who, of the mass producers, do you think has a consistently executed HT?
Just wondered what you thought..
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ESEE, for one. Spyderco is another. Most of the big names have got their stuff pretty together. Ontario's Taiwanese contracter does their HT consistent, too, it's worth noting. It's just the USA-made stuff that's been known to have a good deal of fluctuation.
 
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