Fallkniven A1 Destruction Test Video Completed

So what are you going to break next?:D

Seriously great test. I've always shyed away from an A1 since it's not carbon steel but this has got me looking again. Thanks!
 
I bought an A1 a while back, after using it I dumped 20 yrs worth of collecting knives into a drawer, bought the full set of Northern Light and was done with it. :)
 
Dinkum said:
I bought an A1 a while back, after using it I dumped 20 yrs worth of collecting knives into a drawer, bought the full set of Northern Light and was done with it. :)
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Excellent! :thumbup:

I intend to do pretty much the same thing, as soon as the money comes along.... ;)

Stay sharp,
desmobob
 
Noss4

Great test. You are getting better and better. Watch out myth busters ! :)

I noticed that you mentioned that you got cut when the knife fall from the sheath or s/g in that line. I bought the A1 with both the Kydex and Zytel sheaths and returned the Zytel one. The reason is that although the Zytel sheath is narrower and more compact it does not held the knife as securely as the Kydex one.

If you hold the knife upside down and shake it vigorously usually the A1 falls from Zytel sheath but it is much harder, I actually never managed, to disengage the Kydex lock by shaking the knife.

I wonder if somebody has heard why Fallkniven is no longer offering the Kydex sheath as an option?
 
HoB: Thanks. I understand a precise figure could not be obtained. I just thought of maybe a rough unofficial figure.


mmmotorcycle: Your welcome. I plan on testing/breaking:D The SOG SEAL knife next. I'm going to start it this week. The test fully takes place underwater so it may take me a few days/sessions to complete it because of air supply and being underwater. Anything and everything can go wrong but it is going to be a lot of fun and hopefully informative about underwater knife use. I'm a diver but I never get to use my knife underwater. Most recreation divers don't. At least not anything compared to like in the woods.

vvk: Thanks. The underwater test is going to be like myth busters for sure. The zytel sheath does not hold it very secure. The slightest shake and it will fall out but like you mentioned it is very compact. This is one thing I like about it and failed to mention in the video. If I carried the knife as a EDC I would use the zytel sheath.

I want to thank vvk because it was him that requested the A1 a while back that got me seriously looking at the A1. I might have passed it over otherwise.
 
Cobalt said:
here is my problem with the Cold Steel Trail master. If you look at Noss's pics of the A1's tang, you will notice the smooth transition from blade to tang, which eliminates stress risers.

Cold steel on the other hand, makes a square transition under the kraton where you cannot see. this is a severe stress riser and the likely place where I knife will snap in two. In the ic below, is a Busse Basic 9 with well radiused transition and a Cold Steel TM with a poorly radiused transition. Not good on such an expensive knife.

busse-tm-tangs.jpg
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Yes the radiused transition is much better. In the photo below you can see the K-bar heavy bowie is also radiused. During the destruction test I placed the knife in the vice and beat the hell out of the handle with a hammer and you can see it never broke at this location. It surly added to it's strength.

obj363geo291pg17p9.jpg
 
noss4 said:
HoB: Thanks. I understand a precise figure could not be obtained. I just thought of maybe a rough unofficial figure.


mmmotorcycle: Your welcome. I plan on testing/breaking:D The SOG SEAL knife next. I'm going to start it this week. The test fully takes place underwater so it may take me a few days/sessions to complete it because of air supply and being underwater. Anything and everything can go wrong but it is going to be a lot of fun and hopefully informative about underwater knife use. I'm a dive but I never get to use my knife underwater. Most recreation divers don't. At least not anything compared to like in the woods.

vvk: Thanks. The underwater test is going to be like myth busters for sure. The zytel sheath does not hold it very secure. The slightest shake and it will fall out but like you mentioned it is very compact. This is one thing I like about it and failed to mention in the video. If I carried the knife as a EDC I would use the zytel sheath.

I want to thank vvk because it was him that requested the A1 a while back that got me seriously looking at the A1. I might have passed it over otherwise.
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I look forward to seeing that! With new variables and a new environment it ought to be real neat.
 
noss4 said:
HoB: Thanks. I understand a precise figure could not be obtained. I just thought of maybe a rough unofficial figure.
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Well, with a lot of assumptions, we can do some guess work and you can see how the individual components enter.

Energy is equal to Force times distance : E=F*d

Energy is equal to mass/2 times velocity squared: E=m/2*v^2

When you bounce you let the mass of the upper body drop a certain distance and then you suddenly stiffen the knees upon which the blade has to stop the inertia and return it by bending and flexing back.

Since you said you are weighing in at 225 pounds, lets assume that your upper body weighs about 180 pounds which you drop by only 1" (2.5 cm) within about 1/5 of a second (I tried some bouncing and these numbers seemed resonable since you were bouncing only very little, but no guarantee and there is at least a factor of 2 possible error). Which means you are generating an energy of

E=180/2*0.25^2=1.4 (we use meters and pounds which will give the force also in pounds)

From the video, I would say the blade flexed by about 1/4" which means the knife applied a force over 1/4"=0.6 cm to stop the energy and to turn it around (the knife springs back), which means we have to double the force (that is the typical elastic case):

F=E/d=1.4/0.006*2=460 lbs

So you easily double the static load even with just a little bouncing. However, there is one caveat: Many structures will hold a certain load for a short time but not indefinitely. A climber carabine will for example hold 6000 lbs if the climber drops and gerates a large momentary force, while the same carabine will probably not even support a 2000 lbs car hanging from it statically. Finally there are shock loads (such when performing a Charpy test), which are applied very rapidly. So time plays a big role when testing the strength of a material.

You see there are a lot of variables in this calculation, too many to say something meaningful.
 
HoB: Thanks, This gives us an idea of what was happening with the load
on the A1. Very helpful. Thanks for sharing your brain. :)

The numbers you give are not far off from the Fallkniven's break test. http://www.fallkniven.com/test.htm They show the A1 breaks at 556 lbs
 
Pretty good test. I never would have thought A1 could take that much abuse. Fallkniven deffinately know what they're doing.
 
I find it odd that no one has noticed or pointed this out yet- The whole point of using a laminated blade is so the sides are tougher and more ductile than the core steel. This way the softer sides help support the core steel, increase the shock resistance for the blade as a whole, and should still hold the piece together for a little longer even if the core cracks, or stop a crack. This sounds like Fallkniven's goal as well, if they're using 420 to support VG-10.

However, in this case, the side lamination cracked right away, while the core continued to take the punishment without the support from the softer side. To my thinking, the softer steel on the side never should have cracked in the first place. The alloy should be chosen & heat treated for toughness so you could bend it into a pretzel. Likewise, if the core steel held up so well even after the side broke away, what's the point of using laminated construction in the first place? Why not make the whole thing out of homogeneous VG-10?

What we've seen happen to this blade is not consistent with the traditional or accepted reasons for using laminated construction.
 
Take a HSS hacksaw blade and bend it until it breaks, it will take a large angle because it is so thin, the strain through a metal at a given angle will be proportional to its thickness. This is why angles should never be quoted alone and by using this fact, many blademakers get huge bends by just tapering the knives.

Now if you take that same HSS blade and thicken it past 0.050" into 0.25" to make a heavy use knife blade, then it will now crack at much lower angles. If you laminate it with 1045 at 45 HRC then it will bend at much larger angles than the full 0.25" thick HSS blade but still may not reach the extreme angles that the thin 0.050" HSS blade would by itself.

-Cliff
 
the possum said:
I find it odd that no one has noticed or pointed this out yet- The whole point of using a laminated blade is so the sides are tougher and more ductile than the core steel. This way the softer sides help support the core steel, increase the shock resistance for the blade as a whole, and should still hold the piece together for a little longer even if the core cracks, or stop a crack. This sounds like Fallkniven's goal as well, if they're using 420 to support VG-10.

However, in this case, the side lamination cracked right away, while the core continued to take the punishment without the support from the softer side. To my thinking, the softer steel on the side never should have cracked in the first place. The alloy should be chosen & heat treated for toughness so you could bend it into a pretzel. Likewise, if the core steel held up so well even after the side broke away, what's the point of using laminated construction in the first place? Why not make the whole thing out of homogeneous VG-10?

What we've seen happen to this blade is not consistent with the traditional or accepted reasons for using laminated construction.
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I think you're a little confused about the way lamination is supposed to work, but I may be wrong, too. (Only mortal, and all that. Heck, I make a career out of being mistaken. :D )

First of all, the side lamination didn't crack "right away." It cracked after the knife handle was repeatedly jumped on by a 220 pound grown man. What happened there was that the break point of the knife was reached. It couldn't take any more, so something had to break. One of the laminate sides broke. That, to me, seems to be exactly as designed - the laminate protected the core itself from cracking. Without the lamination, the entire knife would have cracked in two. Now, it could still be used, although it was partly broken.
 
Cliff Stamp said:
Take a HSS hacksaw blade and bend it until it breaks, it will take a large angle because it is so thin, the strain through a metal at a given angle will be proportional to its thickness. This is why angles should never be quoted alone and by using this fact, many blademakers get huge bends by just tapering the knives.

Now if you take that same HSS blade and thicken it past 0.050" into 0.25" to make a heavy use knife blade, then it will now crack at much lower angles. If you laminate it with 1045 at 45 HRC then it will bend at much larger angles than the full 0.25" thick HSS blade but still may not reach the extreme angles that the thin 0.050" HSS blade would by itself.

-Cliff
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And what if you take three 0.05" hss blades, tape them side by side for laminated super blade and then bend them?
 
Elen: Yes your correct the outer layer protected the VG-10 layer from breaking preventing a catastrophic failure of the entire blade. The lamination did it's job.

the possum: like Elen said it did not break immediately. I first had the blade inserted in the holder about 7/8's of an inch from the handle and it took my full bouncing load. I moved the blade out of the holder about 2.5 inches form the handle and it took my full bouncing load for a small amount of time before the outer layer gave way.

Like HoB said steel will take a full load for a while but will not hold it indefinitely.

When downward force is being applied to the knife the top outer layer was being pushed down and was being stretched. the bottom outer layer was flexing inward and compressing absorbing the load.

The outer layer is softer from the inner core you can see this in the below photo it is bent and held the bend.

obj883geo699pg38p9.jpg
 
Elen said:
I think you're a little confused about the way lamination is supposed to work, but I may be wrong, too. (Only mortal, and all that. Heck, I make a career out of being mistaken. :D )

First of all, the side lamination didn't crack "right away." It cracked after the knife handle was repeatedly jumped on by a 220 pound grown man. What happened there was that the break point of the knife was reached. It couldn't take any more, so something had to break. One of the laminate sides broke. That, to me, seems to be exactly as designed - the laminate protected the core itself from cracking. Without the lamination, the entire knife would have cracked in two. Now, it could still be used, although it was partly broken.
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Actually I think that with that logic it should have been the vg-10 core that should've broken inside the laminate. Not the ductile sides.
 
PatriotDan: with three layers of steel and top force and bottom force factors happening the same time to me the top layer is going to give first under the load this makes since to me. If I'm wrong then some one please correct me.

The VG-10 layer is thin compared to to full blade made of solid VG-10 so it is going to flex more. Cliffs example with the hack saw blades is a good one. One hack saw blades would flex more by itself then if you had many layers stacked on to of one another but it would increase it's overall force needed to make a bend.

Also with multi layers of steel or any other rigid materials each layer will shift for the one on top of it. If you place hack saw blades of the same length on top of one another and flex the entire structure you will see the the ends of the hacksaw blades move away from each other in a stair like pattern. The will not longer be even.
So there is several different factors happening with the laminated blade under a load.
 
Cliff Stamp said:
Take a HSS hacksaw blade and bend it until it breaks, it will take a large angle because it is so thin, the strain through a metal at a given angle will be proportional to its thickness. ...Now if you take that same HSS blade and thicken it past 0.050" into 0.25" to make a heavy use knife blade, then it will now crack at much lower angles.
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Yes, Cliff. I am fully aware of this. 420 stainless tempered down to provide the lauded "springy" sides should be ductile enough to bend quite a bit without breaking. Take a soft POS pakistani 420 stainless blade 1/4" thick, and you can bend it a huge amount.

It couldn't take any more, so something had to break. One of the laminate sides broke. That, to me, seems to be exactly as designed - the laminate protected the core itself from cracking.
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No, that is not how this design is supposed to work traditionally. The sides are supposed to hold the blade together after the harder core steel has cracked. If this was indeed Fallkniven's goal, I guess that's up to them. But what happened here is not what people usually talk about when they're praising the virtues of laminated blades.
 
the possum said:
420 stainless tempered down to provide the lauded "springy" sides should be ductile enough to bend quite a bit without breaking. Take a soft POS pakistani 420 stainless blade 1/4" thick, and you can bend it a huge amount.
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One thing I would be interested in was the heat treatment, VG-10 austenizes a lot higher than 420 and those cheap 420 blades are likely much tougher if that is the case.

What I would be concerned about if the sides were made that soft that they could hold even when the very thin core would crack would be the strength. Likely it would be very low.

-Cliff
 
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