Endura 4 Lock Failure

Sal Glesser said:
Hi Vivi,

If it was the lock that broke, it wasn't the ZDP, unless the hardness of the ZDP tang somehow transferred the energy and snapped the lock. The lock isn't made from ZDP.

I would like to see the knife. I'll trade you for an Aqua Salt for it and you can hammer on it.

sal
Click to expand...

It's the blade tang that broke, leaving nothing to engage the lock bar. I sent you an email about mailing the knife out to you. Thanks.

Dog of War said:
Understand, this isn't something I personally do (well, I've done a few tests is all) ... but I'm talking about stuff like Romex, the 14 ga. or larger copper wire used to wire homes and buildings, as well as coax, even soft steel wire.
Click to expand...

I've cut similar things with little to no edge damage using a variety of steels, but part of this is as you explain, I use careful technique. In a similar way if I ever were going to do something like this in a survival scenario or something, I'd be more careful and use carved wedges to take the majority of the stress.
 
Normally it's hard to do edge damage even batoning wood. Logically thinking about it properly batoned the edge only cuts initially once you get the blade in the wood to the full thickness it splits more than it cuts. Sure it cuts but that's not the main force separating the wood.

ZDP is a high wear resistance HARD steel. When you pound on a lockback knife all the force directed onto the hand and not the blade travels to that small little tooth that is the lock face on the blade, do to the location and design hitting the handle with a wood stick put tremendous force on the lock face which cause the lock face to snap of completely.

You did do damage do even your VG10 blades but due to their softness and relative malleability they didn't break like the ZDP did. Don't worry you did damage do the lock face none the less.
 
Sal

The hole cut into the lock bar almost looks like a "keyhole". Is that for stress relief or does it serve some other function?

Also is there also stress relief notch cut into the backside of the lockbar cutout on the blade. i.e. similar to the one seen at the front of the cutout
 
Last edited:
tomcrx said:
Sal

The hole cut into the lock bar almost looks like a "keyhole". Is that for stress relief or does it serve some other function?
Click to expand...

yes it serves for stress relief. It also catches lint.

tomcrx said:
Also is there also stress relief notch cut into the backside of the lockbar cutout on the blade. i.e. similar to the one seen at the front of the cutout
Click to expand...

No, the lockbar is a different material and it's heat treated to a softer Rc.

sal
 
Thanks Sal

I was curious because it seems if the lockbar was static, i.e. could not pivot around it's pin, a fracture like that could be induced.

A couple scenarios would be:
-you batoned on the handle, therefore the lockbar
-the lockbar got "pinched" between the two liners
-The lockbar pin got peened or deformed
 
Vivi, I don't know what you make of this , if anything. I'll also state that with over 20% carbide percentage,and a RC in the middle 60's the steel is not the best to resist impacts and shocks. I recall a picture of an S7 blade OTOH posted by one of our forum knifemakers twisted up like a pretzel, but not broken.

In addition, you are a pretty large, powerfull man. Maybe stronger than you know eh? :)

I've always been told to keep folders unlocked when batoning too. I believe that's proper batoning etiquette nowadays.

I do enjoy your zero edge sharpening tests though. If I ever get an extra ZDP endura I'll send it to you. Now I don't have one available unfortunately.

BTW, that scenery reminded me of the Cuyahoga river valley where I grew up. I was about halfway between Akron and Cleveland. Joe
 
Last edited:
I suppose this is one of those instances where a laminated ZDP/420j2 blade would have fared much better.
 
65535 said:
You did do damage do even your VG10 blades but due to their softness and relative malleability they didn't break like the ZDP did. Don't worry you did damage do the lock face none the less.
Click to expand...

Agreed. I could see the VG10 knife flex in the wrong direction in the vid. Vivi, is there any vertical play in the VG10 Endura? If not I gotta get one.:)
 
I suppose this is one of those instances where a laminated ZDP/420j2 blade would have fared much better.
Click to expand...

Probably not much. If so it would be other reasons, like shorter length blade/handle building up less force. The lamination isn't really thick enough to make much of a difference, IMO. Just a guess though. Joe
 
The 420 laminated sides on my calypso 3 make up over 2/3 of the blades thickness. The ZDP might still crack but the 420 should keep the lock functional and in one piece.
 
Yoda, that is still assuming you use proper battoning technique by releasing the lock, right?
 
tomcrx said:
I disagree on this I have used CS Voyagers and Enduras to cut through Romex and extension cords. I used it just like you cut line, i.e. loop the wire and pull cut through the loop. I have not had any damage on the knives. I have also used both to cut through asphalt shingle, aluminum and vinyl flashing with no issues. Many times I have trimmed these materials like you would whittle a stick. This puts tremendous lateral force on the edge and had nary a problem except an occasional rolled edge. You are in fact cutting material that is significantly softer the hardened cutlery steel and should not pose a huge problem.
Click to expand...
Well, you and I may just have to agree to disagree. :) I've seen the damage this can cause, have replicated same in my own tests, and still hold that materials significantly softer than than a steel blade can seriously damage an edge.

.
 
Dog of War said:
Well, you and I may just have to agree to disagree. :) I've seen the damage this can cause, have replicated same in my own tests, and still hold that materials significantly softer than than a steel blade can seriously damage an edge.

.
Click to expand...

I can agree to that :) In my experience the only time I have broken folders, i.e. caused either gross fracture of blade or lock, is by prying or batoning. I have rolled and dented edges, I just don't consider that serious damage since it is easily sharpened out.

I really like what Vivi is doing in practically demonstrating that thin edge profiles are more robust then the normal knife user has imagined.
 
tomcrx said:
I really like what Vivi is doing in practically demonstrating that thin edge profiles are more robust then the normal knife user has imagined.
Click to expand...
Yes, I've been advocating on these forums for some time that a good "default" primary sharpening angle for most knives is 12 degrees/side, assuming of course the addition of a microbevel. 15 deg./side IMO is a very robust profile suitable for the heaviest work, anything more obtuse than that just isn't necessary.
 
hardheart said:
cause that would really help when evaluating a knife
Click to expand...

How does an uncontrolled test, testing a function for which the knife is not designed of course, offer any real help except to say, "folders are not the best tool for batoning"? Something that most of us already realize.

If it were controlled, and repeatable within an acceptable margin of error, it would at least allow us to discover roughly how much force it takes before the tang/lock area fails.

But, as it is, what we get is one guy recording himself beating the bejesus out of an elegantly designed little folder and some other guys coming along and acting as if it is necessarily a design or production defect. I don't mind this, and actually think that Vivi has something to offer here, but call it what it is. The only real useable information to be gathered here, short of analysis at Spyderco, is that folders are not designed for batoning.

Introducing an axe into the mix makes as much sense as just about anything else I've seen here.


Vivi- You don't test a knife edge by stressing the locking mechanism. Try cutting stuff. :D Cardboard and hemp or manilla rope are both reasonably abrasive and uniform, good for testing the steel on a folder's edge.
 
Last edited:
Yes, lets beat on a folder until a small piece of metal (maybe the size of a dime or less) breaks off. Then we can all scratch our heads and ask Sal, gee, why did it break?

Defect? Bad heat treat? Yeah yeah, that must be it...nothing to do with totally unreasonable abuse.

To accept a free knife from Sal is shameful.
 
You must log in or register to reply here.
Back
Top