Bk-9 failure

L

ls1

Joined
May 28, 2009
Messages
36
Was chopping hemlock and I look down to see this...I don't think chopping wood is out of the realm of a big survival blade. I don't bellieve I was abusing it either. Bad heat treat possibly? Sometimes stuff happen with mass produced blades. Outside temp was about 50F.

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Sigh...well I guess Ka bar gets a call monday.
 
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Yowch. That is unusual for a high carbon blade to chip so drastically. I'm sure Kabar and Mr Becker will help you find a solution.

Testimonial is not always positive, so thank you for sharing.
 
Well, I'm gonna give Ka bar the benefit of the doubt and not bad mouth them just yet., I'll give them a call and see if they'll send me a replacement (assuming I send this one back). I have another Ka bar product I love so...
 
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That is a real bummer. it can happen. Here is a pic of my 1085 cutlass machete that blew a chip out. It was about .5" accross. I was harvesting fatwood and hit a very hard knot at an angle. You could hear the chip fly out like a bullet richoceting.
I ground the chip out and convexed it. No problems since.
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Ka-bar will replace it. I have no doubt!!!
 
I used my BK-9 a lot today clearing trails and I caused a little ripple right above the edge. The actual edge held up perfectly, no chips or rolls.
As much as I love the ultra thin grind Becker is putting on their knives, I think they may want to consider thickening it a bit for the BK-9.
There's a lot of force in a full power chop and if you hit the wood at the wrong angle it seems like it can be a problem.
The OP may have had the same thing occur before the steel became brittle in that section and blew out.
The BK-9 has by far the thinnest grind of any factory-made chopper I've seen.
 
cody1 said:
That is a real bummer. it can happen. Here is a pic of my 1085 cutlass machete that blew a chip out. It was about .5" accross. I was harvesting fatwood and hit a very hard knot at an angle. You could hear the chip fly out like a bullet richoceting.
I ground the chip out and convexed it. No problems since.
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IMG_4076.jpg


Ka-bar will replace it. I have no doubt!!!
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Man, Fatwood can be the hardest stuff you will ever chop.

I have two big stumps in the back yard. I got them to throw tomahawks and knives at. Well, they won't work for that......at all. They will bounce a well thrown hawk or knife right off. I have a 9lb or 10lb maul.....a real beast for chopping the wood. A good log with a fatwood core will bounce that maul even. I had one I was splitting, after about 20 or so full power swings, I had barely creased the center. It was like I was hitting concrete. I did not realize the piece I was splitting was fatwood. I don't even know what kind of tree it was (we harvested that wood well over a decade ago). I got some great fatwood out of those though. Much too pitchy and smoky to burn in the wood stove, but the cores were great for firemaking kits.

I have a thrower made of high carbon steel. Thicker grind I have bounced it off the hardened hammer poll of my Hawk a few times with out too serious of damage. I had a real hard throw hit perfect point first, but the knife bounced away with a clang (same with heavy hawk throws with perfect hits, barely marked the surface of the wood, and bounce off with a clang). Bent the tip 1/2 inch up almost 90 degrees. this is a knife I have been using hard for years and years without ever an issue.

So you can find wood that is as hard as stone almost!





I would contact Becker, and send that puppy in for a replacement.
 
Even well heat treated steel can fail when hitting hard wood and knots. Some are as hard as glass. Kabar/ Becker is a respectful company , and I'm sure they will help you.

I noticed the 9 has a thin edge also. ( just got mine last week). I plan to convex it to sturdy up the edge some.

Hope you get that resolved soon.
 
hiwa said:
Even well heat treated steel can fail when hitting hard wood and knots. Some are as hard as glass. Kabar/ Becker is a respectful company , and I'm sure they will help you.

I noticed the 9 has a thin edge also. ( just got mine last week). I plan to convex it to sturdy up the edge some.

Hope you get that resolved soon.
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hemlock cores, especially the knots, is a very touch HARD wood. the knots on many kinds of such slower? growing everygreens/fir trees are often silicated (impregnated with sand basically). so, you ARE hitting rock, literally...

i've bent a quality axe head while limbing a downed old hemlock, was going through the knots at a nice angle, and sometimes i was getting SPARKS... and then i bent the head. hammering it back actually worked to 98% and hopefully work hardened it some - reprofiled and polished it up at one point later - it's a keeper.

several other people have BROKEN clean through some Patrol Machetes while chopping up a XMAS tree. yes, a pidly little XMAS tree limb broke a 1/4 thick knife. another one was chipped.

i think we also saw another BK-10 get chipped while chopping daDaDA some kind of fir tree through the knots.

so, where am i going with this? wear gloves and eye protection. XMAS trees are killers!


Bladite
 
Bladite is right -hemlock has lots of small hard knots. We have many hemlocks here in the Catskill Mtns and the area was famous for tanning operations where hides were sent from long distances. Places like Tannersville !
 
mete said:
Bladite is right -hemlock has lots of small hard knots. We have many hemlocks here in the Catskill Mtns and the area was famous for tanning operations where hides were sent from long distances. Places like Tannersville !
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i've been to Tannersville. good icecream. brought my Becker's when camping :>


Bladite
 
hemlock is brutal stuff, esp the knots. I've had thickness planers blow out blades on hemlock knots.
 
Hey Everybody......

Horace Kephart, the greatest of all outdoors writers warns specifically about hemlock knots chipping axe blades....Had it happen to me with a brand spanking new U.S. made Plumb Axe about ten years ago and I assume it had an R-C in the low fifties......In my experience the only other thing that will screw up a well made knife is throwing it.....There is a reason throwers are kept in the high forties to very low fifties.....I do not know what does it (my best and only guess is a resonance that does something to the crystal structure but I do NOT know) but, I know it happens and the longer the blade I THINK the more likely it is......

Check with Tooge on monday......

All Best....

ethan
 
Well, I don't throw my knives that much I know for sure. Esp not knives like this.
 
Hey Is1.....

Usually if you get a throwing failure the knife snaps in two.......BTW Kephart also warns about balsam knots, for what it is worth....My Plumb lost a chunk about the size of half a silver dollar........Hate it when stuff like this happens and I am sorry that it happened to you.....

All Best....

ethan
 
Hey Is1.....

Usually if you get a throwing failure the knife snaps in two.......BTW Kephart also warns about balsam knots, for what it is worth....My Plumb lost a chunk about the size of half a silver dollar........Hate it when stuff like this happens and I am sorry that it happened to you.....

All Best....

ethan
 
Thanks Mr. Becker. I'm not bad mouthing your product, stuff happens. I don't think I hit a knot, but you know, it's just hard to remember sometimes.
 
Why does it half moon in shape when it chips ?

Got me curious to why.

Regards, Tim
 
Just stumbled into this thread when I was looking for bk9 pics as I was considering one as a project knife to full convex/satin/switch scales.

A blade designed to "chop wood", should be able to handle chopping wood, i've yet to have an edge blow out like that against any kind of wood. The worst i've experienced in that regard would be a Busse Sarsquatch which I thinned/convexed the edge to roughly that of a scalpel to see how it would perform in with that geometry, I also reground the entire primary grind to thin that some starting with 40 grit belts and working up to high grits for the satin finish, I wanted an insane slicer and that's what I got.

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The edge held up fine, chopping smaller, lighter stuff. In fact it held up perfect until I brought it ice fishing one day and was using it to chop up some frozen wood for our burn barrel.

What did it in was a combination of frozen wood and lateral force being applied to the knife to pull the blade out. This coupled with the fact that I had very literally ground the edge into a straight razor caused the edge to dent and bend to the side.

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In the end, I reground the knife slightly more obtuse and it held up perfectly, even very thin.

What I didn't experience is any tear out or chip. A hard use fixed blade should be heat treated so that it shouldn't be chipping out, but rather denting instead. Especially a fixed blade made of 1095 meant for hard use. I honestly know NOTHING about Beckers and I just kind of wandered in here looking for a project blade to mod, but i'm assuming this is a bad HT. For the record, I was chopping up and splitting some larger pieces of hemlock yesterday filled with knots with a battle mistress and experienced no chipping or denting, knots should not remove a chip from a blade, the most i'd expect from a blade designed for use as a survival blade is denting if the blade was tempered properly for the application.

I'm not saying beckers aren't, so don't jump down my throat, just offering some input. I'm still going to purchase some beckers to mod.
 
Hey Is1 and Cody1,

Call me @ 1-800 282-0130. My extention is 208. If you guys send the knives in, we'll replace them.

Best Regards,


Paul Tsujimoto
Sr Eng.
Prod Dev and Qual
KA-BAR Knives
 
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