A2 Steel Update

goldie said:
Not sure why theres so many complaints about the sheaths; ive been using them for years never saw any dulling of the blades,and i like that i can remove the belt loop and add a teklok to it.
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It seems to be a YMMV thing. I haven’t noticed any significant dulling on my end yet, but then again I consciously apply pressure on the spine as I unsheathe and resheathe.
 
Mine was fine until my Recon Tanto was dropped while in the sheath, it dulled it instantly and ever since that it'll dull it if I put it in the sheath and carry anywhere. I had great deal of issue because of it.
 
As promised, testing 4034SS. Andrew took the time to take an off the shelf Outdoorsman Lite in 4034SS (4mm thick) and ran it through its paces for you all. Spine whacks at weights far beyond what we normally test and and even further beyond the capability of hand held exerted force. Over 200 1" rope cuts (definitely could've kept going - he can chime in on that), bending further than would ever occur by hand. Now, take this 4mm knife and double it in thickness and imagine the strength. We hope you guys will watch this and understand that it is not a crappy liner steel and when done properly it can be great.

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" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
DangerZone98 said:
It seems to be a YMMV thing. I haven’t noticed any significant dulling on my end yet, but then again I consciously apply pressure on the spine as I unsheathe and resheathe.
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This is my experience too. Applying pressure to the spine when drawing the knife has always elliminated edge rubbing. But perhaps some sheaths don't offer as much clearance.
 
Cold Steel Knives said:
As promised, testing 4034SS. Andrew took the time to take an off the shelf Outdoorsman Lite in 4034SS (4mm thick) and ran it through its paces for you all. Spine whacks at weights far beyond what we normally test and and even further beyond the capability of hand held exerted force. Over 200 1" rope cuts (definitely could've kept going - he can chime in on that), bending further than would ever occur by hand. Now, take this 4mm knife and double it in thickness and imagine the strength. We hope you guys will watch this and understand that it is not a crappy liner steel and when done properly it can be great.

<iframe width="560" height="315" src="
" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
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Thanks for the video! Very interesting.
 
I love the Outdoorsman Lite. And I like 4034 too. It seems to hold an edge at least as well as SK5 but it's tougher. SK5 is easy to sharpen but 4034 is just as easy and gets sharper easier. Using a steel from this class is a brilliant idea. I'd prefer AEB-L or 12C27, but my guess is that 4034 is the highest carbon member of this class that can be blanked. These steels have a very fine grain structure and form very small and hard chromium carbides that make them tough and take a fine edge. For the same reason they're easy to grind, polish and even blank. If the price is what I expect, I'll buy every model.
 
Nice video, but how does the “accelerometer” work? Wouldn’t the falling plates fall at the same rate (the rate of gravity). The acceleration would be the same regardless of the amount of weight. The stopping force would be different, due to the change in mass, but since the blade is free swinging, it is not stopping the momentum.

n2s
 
not2sharp said:
Nice video, but how does the “accelerometer” work? Wouldn’t the falling plates fall at the same rate (the rate of gravity). The acceleration would be the same regardless of the amount of weight. The stopping force would be different, due to the change in mass, but since the blade is free swinging, it is not stopping the momentum.

n2s
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I believe the speed will be different until Terminal Velocity is acheived, that being the maximum speed an item can fall due to gravity. The heavier weight should achieve this speed faster. *It's been a really long time since I took any science class, so please correct any mistake:D
 
It's not just falling...it's pivoting on an axis, creating torque. The heavier the weight, the more torque. Can google the physics of a trebuchet for more info...very similar.
 
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jdk1 said:
I believe the speed will be different until Terminal Velocity is acheived, that being the maximum speed an item can fall due to gravity. The heavier weight should achieve this speed faster. *It's been a really long time since I took any science class, so please correct any mistake:D
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It has been about 35 years for me as well (I am getting old). However, my recollection is that objects on earth will drop at 9.8 meters per second. They are subject to air resistance or water resistance (eg. if thrown in an ocean), but otherwise constant. In a perfect vacuum it wouldn't matter if I dropped a sheet of paper and a cannon ball, they would both fall at the same rate. Here the air resistance is negligible. Just the small amount displaced by the weights as they fall and the drag of the arm and knife. The arm also acts as a counterweight, and detracts a bit from the mass, but the object will still fall at the same speed, because whether the 10 lb weight drops with a net mass of 5lbs, or 100lbs would not change the rate.

n2s
 
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jlauffer said:
It's not just falling...it's pivoting on an axis, creating torque. The heavier the weight, the more torque. Can google the physics of a trebuchet for more info...very similar.
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Yes, the momentum is different, but the knife is not trying to stop the motion of the device, it is just impacting at a constant rate of rotation. On a trebuchet, an increase in the counter weight can be used to throw a heavier projectile at the same speed, or to extend the arm which would throw the same projectile at a greater speed.

n2s
 
not2sharp said:
Yes, the momentum is different, but the knife is not trying to stop the motion of the device, it is just impacting at a constant rate of rotation. On a trebuchet, an increase in the counter weight can be used to throw a heavier projectile at the same speed, or to extend the arm which would throw the same projectile at a greater speed.

n2s
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All else being equal, a heavier counterweight would throw the projectile farther than a lighter counterweight, so obviously the arm is moving faster with the heavier counterweight.
 
It may not be faster but has more momentum. You can tell just by watching the video that additional weight made the knife smack harder. I’m pretty sure A.D. knows how to test knives and which tests are relevant from an engineering perspective.
 
Momentum = Mass x Velocity, so since the mass of the knife is fixed, the only way to increase its momentum is to increase its speed, which is done by increasing the counterweight.
 
not2sharp said:
Yes, the momentum is different, but the knife is not trying to stop the motion of the device, it is just impacting at a constant rate of rotation. On a trebuchet, an increase in the counter weight can be used to throw a heavier projectile at the same speed, or to extend the arm which would throw the same projectile at a greater speed.

n2s
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The knife goes faster with heavier weights. The weight is not in free fall. Its force toward the Earth is resisted by the rotational inertia of the arm and knife. More weight-> more torque -> more knife/arm acceleration -> more knife speed. As someone said, you can see it going faster too. (Aced physics 110 decades ago.)
 
Mark Spark said:
I'd prefer AEB-L or 12C27, but my guess is that 4034 is the highest carbon member of this class that can be blanked
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Nope. It's one of many steels that can be blanked/die cut and 4034 isn't the anything performance wise. My guess is it's the most available in the quantity/quality/price/location needed for Cold Steel to get to the vendor in a timely fashion with the reliability to not have what happened with the A2 happen again.


"It seems to hold an edge at least as well as SK5 but it's tougher"

I'm curious about your test knives and methodology or are you figuring things out from reading posts and watching videos?

"SK5 is easy to sharpen but 4034 is just as easy and gets sharper easier."

Huh? Can you explain this please?
 
Let me try to explain. I've been comparing a 4034 Outdoorsman against a SK5 SRK for a few days. I sharpen them variously with DMT diamond plates, waterstones, and a Sharpmaker. Also use leather strops with good Russian diamond paste. Then I test sharpness with computer paper and my fingers. Then I dull them carving Doug fir. Then check sharpness again. Most people can't distinguish sharp from really f'ing sharp. To push-cut paper at a 90 degree angle requires really sharp. If you tilt the knife any, or move in a slicing motion any, it's much easier to cut paper. Knowing this I can distinguish high levels of sharpness from ordinary sharp.
What you find is some steels are easy to get really sharp, and some are difficult. For example, to get S110V to even cut paper requires diamond abrasives and good technique. To get it really sharp requires good strops and a lot of patience. On the other hand, you can get 4034 to push-cut paper properly in no time at all. Just apex on a DMT fine plate, then 10 strokes each side with Spyderco extra fine rods, and voila. Crazy sharp. No battling burrs, no progression through strops. The only other steel that behaves as well is LC200. 8Cr13MoV is close, and AUS8 also.
Also I find, and here this is anecdotal, not scientific, that edge retention at very high levels of sharpness does not depend very much on the steel. It's not like a Catra test which measures gross wear. Those big Vanadium carbides don't wear but they aren't very sharp either.
I've been studying metallurgy and there are good technical reasons why 4034 is very tough, takes a super fine edge, and is low cost to blank, grind and polish. I believe it will give superior performance to many surprising steels including 1085 and 52100 when it's hardened to 57.5. I believe they're using cryo to get this, like Buck and 420HC. Time will tell.
If people like 3V, I think that's great. I see using Japanese 4034 with cryo as an elegant engineering solution and that really appeals to me.
Any questions?
 
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