List of ZTs that Don't Have Lock Failure Issues

[Steely_Gunz]

I don't spine whack mine either. I just do check a static test just to make sure they're not glorified slipjoint knives, and I've had a couple from ZT with locks that shift from hand pressure. That's what concerns me.

I think I sometimes gloss over this issue when I report my ZT issues. Whacking a spine of a knife is suppose to simulate hard use quickly. I think people put too much stock in this. It's the same folks who get bent out of shape about the FBI recommended bullet ballistic and penetration measurement when 100 other things could affect a shooting.

However, my 350, 630, and 909 slipping off the lock with static pressure worry me a lot more than my other ones jumping off the lock due to the shock. I could certainly see using my 909 for some outdoor task and hitting that sweet spot with enough pressure and causing it to fail. Being that it is a liner lock, gripping it "like a man" won't help like it might on the 630's frame lock. Steel on steel liner locks are pretty dead simple for a manufacturer to get right. Those slipping the lock concern me way more than smacking the back of the blade.

I can live with the 350 slipping a bit as it still has to overcome the spring tension before it comes down far enough to bite my hand. The 909, though, that is buttery smooth to close. If it slips, that big ol' 4" blade is probably going to bite the meat of my fingers if the flipper tab doesn't catch on my hand first.

I'm thinking I may go ahead and send it in. It's not a knife I need day in and day out, and it really does't take much to defeat the lock on my sample.

 

[falar]

Stabbing is exactly what I have in mind, as the forces applied to the lock would be similar. Also, working in tight spaces, one might bump the spine on something. It may not be likely, but it is possible. I prescribe to the maxim that an ounce of prevention is worth a pound of cure, and when it comes to locks, the more prevention the better as far as I'm concerned.

I don't share your concern for stabbing since in that case your hand would be keeping the lockbar in place should it want to move outwards. These spine whack "tests" don't simulate a stabbing motion at all in my opinion.

 

[marrenmiller]

Then my question would be why? ... You wouldn't think a slipjoint would take that type of abuse and a slipjoint will cut and do anything a locking knife will ???

It's just unrealistic and a completely unresponsible way to use any knife ... but ya'll can argue away ... I just posted after it shocked me it was still going after I hadn't looked at the forums for awhile.

Carry on ...

Because it's a locking knife, so the expectation is that it locks and doesn't fold on you when you pull the blade out of something it's stuck in, or stab into material at a bad angle; in my mind this is what differentiates a slipjoint from a locking folder.

Not saying you're wrong. I'm just saying why some, including myself, feel differently.

Not that I do this frequently, but you could also factor in SD as a reason to want a lock. Having a fixed blade or firearm is better, but I can't legally carry either where I live.

 

[Night Rider]

Looking at the design, thickness among other properties I consider the 0393 a linerlock. Linerlocks are weaker than framelocks (scientific fact that ofc has variation on how well produced and many other factors, but as a general rule stands true). While a knife like my Skaha 2 CF can stand some light taps, it is not an overbuilt knife, it is an EDC knife with a lock that won't fail on me. In general I will stay away from hard use knives with a linerlock. I think it is a mistake to consider a linerlock(ish) a hard use knife.


You just listed two liner locks(0350, 0909)... friction and tension plays a large role in lock slippage and linerlocks are far inferior to framelocks in that regard. Linerlocks just aren't as strong as framelocks, especially when you're looking at negative pressure, so your results really aren't surprising. That is why I will always say the ZT 0909 is NOT a hard use knife, along with the 0393. Now, with all that being said, I do think linerlocks on many knives are fine and strong enough during normal use to prevent injury or lock failure that isn't user error induced.

To be fair, the only ZT models I ever had any issue with was the ZT/Emerson collab. I think they made the framelock tension too light in my experience, which allowed for lock-slippage.

A properly done framelock is extremely strong. If you want to see how a framelock can handle abuse:

how it compares to others according to this random guy on youtube:
https://docs.google.com/spreadsheets/d/1Q3Z9koNohHDIUogSVRaIGl-o3mebrbjwSDNcR0h5LlU/edit#gid=0
just another vid of spinewhacking among other things.

Well you proved me wrong Gideons, I guess there ARE a few happy ZT customers willing to take the time to make Youtube vids of their knifes working fine. Thanks for those contributions but I was expecting to see digits and blood flying everywhere on that first vid. That guy had science in mind when he made that vid...

 

[jstn]

If you're so concerned about bumping the spine closed in a crawl space, why not just carry nothing but a fixed blade?

Simple. Because I want to carry a folder.

 

[Horizon7]

Does anybody else think ZT should include a nail nick on the blade, so they are consistent with other slip joints?

 

[jstn]

I don't share your concern for stabbing since in that case your hand would be keeping the lockbar in place should it want to move outwards. These spine whack "tests" don't simulate a stabbing motion at all in my opinion.

You may be correct, and I may be overly concerned. When I was a kid I had a folding knife close on me while stabbing something (liner lock, not frame lock), and ever since I've been paranoid about it, which I why I don't own any liner locks, and only one framelock. Mostly Triads, BBL, Axis, and Comp locks for me.

 

[Night Rider]

I can't lie I saw a few ZT lock fail vids a few months ago and it made me not have any interest in ZT.
But I recently bought a used 0350 and it's such a fantastic knife that I needed to change my tune. I understand its a liner lock but it has made me more then willing to take a chance on a frame lock ZT

Your not alone cbrstar. Reading threads like this got me interested in ZT's also and I ended up buying one while I was out in the field gathering data. Probably just the opposite reaction that the OP's of those threads intended Lol

 

[Night Rider]

Does anybody else think ZT should include a nail nick on the blade, so they are consistent with other slip joints?

^No

 

[stonproject]

You may be correct, and I may be overly concerned. When I was a kid I had a folding knife close on me while stabbing something (liner lock, not frame lock), and ever since I've been paranoid about it, which I why I don't own any liner locks, and only one framelock. Mostly Triads, BBL, Axis, and Comp locks for me.

A balisong would be the best folder if you're concerned about a knife closing on your hand

 

[marrenmiller]

I don't share your concern for stabbing since in that case your hand would be keeping the lockbar in place should it want to move outwards. These spine whack "tests" don't simulate a stabbing motion at all in my opinion.

In theory, yes. I've tried to test that by attempting to pry out the lock bar while I gripped a knife tightly, and found that on most of the framelocks in my possession my hands don't actually put much, if any, pressure on the lock bars. They were just as easy to open when gripped as when not. Ironically, I think they'd be better reinforced by holding them in my left hand.

of course, YMMV.

 

[Silent H]

However, my 350, 630, and 909 slipping off the lock with static pressure worry me a lot more than my other ones jumping off the lock due to the shock. I could certainly see using my 909 for some outdoor task and hitting that sweet spot with enough pressure and causing it to fail. Being that it is a liner lock, gripping it "like a man" won't help like it might on the 630's frame lock. Steel on steel liner locks are pretty dead simple for a manufacturer to get right. Those slipping the lock concern me way more than smacking the back of the blade.

I can live with the 350 slipping a bit as it still has to overcome the spring tension before it comes down far enough to bite my hand. The 909, though, that is buttery smooth to close. If it slips, that big ol' 4" blade is probably going to bite the meat of my fingers if the flipper tab doesn't catch on my hand first.

I'm thinking I may go ahead and send it in. It's not a knife I need day in and day out, and it really does't take much to defeat the lock on my sample.

I have a 909 and had a lock failure while readjusting my grip while cutting a long piece of cardboard. Luckily it didn't actually close on my hand. I looked in the knife with a flashlight and saw that the steel on the lock face had rolled, so the tang was sitting on an angled burr instead of on the top of the liner lock. I suspect that the liner lock steel was softer than it should have been. I sent it back to ZT and they replaced the liner lock side. I haven't had any issues with it since.

 

[Steely_Gunz]

I have a 909 and had a lock failure while readjusting my grip while cutting a long piece of cardboard. Luckily it didn't actually close on my hand. I looked in the knife with a flashlight and saw that the steel on the lock face had rolled, so the tang was sitting on an angled burr instead of on the top of the liner lock. I suspect that the liner lock steel was softer than it should have been. I sent it back to ZT and they replaced the liner lock side. I haven't had any issues with it since.

Thanks for the information. I'll check mine out this weekend.

 

[Steely_Gunz]

Double tap

 

[Huntnow]

Why are you taking this personal? I'm sorry if these threads bring down the worth of your collection. Some ZTs have proven to be dangerous to use, and the knife community needs to know about the many cases of lock failures out there. MANY CASES.

Dangerous? C'mon. As has been asked, how does a spine "whack" even simulate a real world use? Furthermore, If you are using a folding knife in a manner in which a lock failure is dangerous, you should invest in a fixed blade or a pry bar. "Overbuilt" or "beast", whatever the slogan is now, it doesn't mean it's a do everything tool. This thread is getting just silly.

 

[fjblair]

People should just start buying cold steel triad locks if they're so afraid of locks disengaging. I personally don't use my knife hard enough ever for a lock to possibly fail, but I think we need to realize how rudamentary these frame lock/liner locks are. It's literally a piece of metal pryed up against another piece of metal on one slim surface for the convenience of being able to carry a reasonable sized blade in the pocket. Archaic technology, really. With that said, technology has improved enough that the accuracy of these geometries can be done well by any competent company, but us as the end user still have to engage that lock correctly. Even with CRK knives, if you flip the knife open slower than usual the lock bar doesnt engage the same amount as if you flip it open fast, so I dont doubt ZTs may fail depending on how we engage the lock. But in my personal experience ZTs have locked up like vaults for me, but I guess I could have always just gotten lucky.

You didn't get lucky, you experienced the norm. Good write up.

 

[fjblair]

Why are you taking this personal? I'm sorry if these threads bring down the worth of your collection. Some ZTs have proven to be dangerous to use, and the knife community needs to know about the many cases of lock failures out there. MANY CASES.

LOL man get a grip, you are fully invested in this personally. This thread is not going to "bring down the worth" of anyone's collection.

 

[Hackenslash]

Why are you taking this personal? I'm sorry if these threads bring down the worth of your collection. Some ZTs have proven to be dangerous to use, and the knife community needs to know about the many cases of lock failures out there. MANY CASES.

Validate your claims of widespread ZT lock failures with medical records and court proceedings. Until then stop trolling this community.

You’ve actually helped the value of my ZT collection. According to your “expert” opinion, ZTs that lock and stay locked are incredibly rare.

 

[firefighterguy]

Dangerous? C'mon. As has been asked, how does a spine "whack" even simulate a real world use? Furthermore, If you are using a folding knife in a manner in which a lock failure is dangerous, you should invest in a fixed blade or a pry bar. "Overbuilt" or "beast", whatever the slogan is now, it doesn't mean it's a do everything tool. This thread is getting just silly.

We can debate if spine whacks are “real world” and never come to an agreement.

However, ZT has stated that spine whacks are part of their qc and that their knives should not fail during a spine whack. So I think it’s fair for people who have knives that fail a spine whack to be upset that a “proudly overbuilt” knife is essentially a slip joint.

Personally, I believe the issues are due to poor lock geometry. Idk how anyone can think this is safe
It’s important to note that the actual lockbar is engaging only ~10% of the blade.

So to the OP question I’m curious if anyone has an 0393 with good lockup and/or one that can pass a spine whack test.

 

[Horizon7]

Validate your claims of widespread ZT lock failures with medical records and court proceedings. Until then stop trolling this community.

You’ve actually helped the value of my ZT collection. According to your “expert” opinion, ZTs that lock and stay locked are incredibly rare.

You're welcome.