Do your linerlocks "wear out" ?

I've yet to own and use a knife long enough for it to reach end of life but that is just because I haven't been a Knifenut long enough yet. I rotate often enough where that is going to take a very long time too. The only issues I have ever had with a knife is a new knife so far - go figure . . .
 
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2brothers said:
I have/had some knives wear quite a bit but I'm talking about knives I've had for over a decade. Some, not so much.
If I can buy a nice knife (IMO) :) for $100 and it lasts me 10yrs I'm happy.
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If it's only a little bladeplay you're worried about, a knife can last a lot longer than that!
 
I have had some observations.

Liner locks (LL) like my military (spydie) has taken a lot of opening/closing and wear is not noticable. LL like a custom I own has worn out.

Frame locks (FL) like my ZT300 (2nd hand and lockup is still the same) but my CRKT Drifter is at 100%.

What do I mean?
I think it's got to do with the blade tang cutout's profile. In the Mille, the cutout is curved making wear resistance exponentially (not really exponentially but it describes it being more than linear) increasing as it travels due to the contact surface becoming more and more inclined from the perpendicular as it wears.

Straight cutouts wear faster in my observation. Perhaps due to the arc of the lockbar's locktip (imagine it's movement with the relief as the pivot point) resulting it moving further away from the cutout as it wears = less wedging type force.

Just a thought, may not be entirely accurate, but holds true for all my folders.
 
I have my old kershaw chive sitting in front of me with the lockbar engaging over 90% with just a hairs with off the opposing liner.

Thats one of the only quality liner locks I've had that has worn that much, most of mine hit about 50-60% and stop. That chive was used everyday very frequently and often quite hard for 4 years for the $30 I spent on it thats a darn good deal for me, considering Its still very usuable even after the lock wears out.

I completely agree about the curved tang face lasting longer than the straight angled tang face.


Just got my emerson a100 in the other day, now that is a well designed liner lock! nice thick liner, curved face, with a solid detent too.
 
2brothers said:
Not trying to be argumentative here, just want to know what you mean.
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I said that referring to the couple knives I have had that have moved from an approximate 30% lockup to ~75% lock up over a couple months which I think is pretty quick for that amount of movement. I can notice a change in where the lock engages the tang which is what I meant by the part you highlighted.


2brothers said:
Honestly, a spring would start wearing out as soon as you start moving it.
And yes, I do like the Axis lock. I have an HK/BM sitting right here on my desk so I'm not knocking the lock at all.

I started this post to get an overview of why/where/when liner/frame locks would wear.
From the previous posts it looks as if very hard use (pressure and movement) against the bar would wear it out. I can understand that.
Also, "over flicking" your blade open would wear faster too I think.

I have/had some knives wear quite a bit but I'm talking about knives I've had for over a decade. Some, not so much.
If I can buy a nice knife (IMO) :) for $100 and it lasts me 10yrs I'm happy.

Appreciate all the responses fellas.
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And yes a spring does start wearing from when it is first used. But a well designed spring should last a long time if it is not pushed past it's yield strength and into plastic deformation. It is complex but most springs should last a really long time. I know there are some threads on Benchmade Omega springs breaking but I would love to know how many actual failures there are out of how many springs there are in use out there. I would be willing to bet that the ones reported on this website would be statistically zero. Regardless, they do occasionally break but I can easily fix the problem as I have done. I took about 5 minutes with a piece of MIG wire and needle nose pliers to make a working omega spring that has been working perfectly for about 2 years. It's not a big deal to me because it is so easily replaced and if I didn't feel up to it I could send it to Benchmade and they would throw a new set of springs in. But other than omega springs you don't read much about springs breaking around here.

Hope my 2 cents wasn't too long winded.
 
Liner- or frame-locks wearing out? Nope. Mine (eleven linerlocks & three framelocks so far) are all still pretty much where they were when I got them, and some I've used really hard.

thx - cpr
 
FlaMtnBkr said:
I said that referring to the couple knives I have had that have moved from an approximate 30% lockup to ~75% lock up over a couple months which I think is pretty quick for that amount of movement. I can notice a change in where the lock engages the tang which is what I meant by the part you highlighted.




And yes a spring does start wearing from when it is first used. But a well designed spring should last a long time if it is not pushed past it's yield strength and into plastic deformation. It is complex but most springs should last a really long time. I know there are some threads on Benchmade Omega springs breaking but I would love to know how many actual failures there are out of how many springs there are in use out there. I would be willing to bet that the ones reported on this website would be statistically zero. Regardless, they do occasionally break but I can easily fix the problem as I have done. I took about 5 minutes with a piece of MIG wire and needle nose pliers to make a working omega spring that has been working perfectly for about 2 years. It's not a big deal to me because it is so easily replaced and if I didn't feel up to it I could send it to Benchmade and they would throw a new set of springs in. But other than omega springs you don't read much about springs breaking around here.

Hope my 2 cents wasn't too long winded.
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Finally, some introduction of intelligence to the age old 'breaking Ω springs' argument. I have never had an Omega spring break, but I'll wager that a large part of the failure is when users repeatedly flip their knives open and closed in rapid succession. This assumes that such activity will cause a hardening of the spring. In any event, as you say, when the number of Omega springs in service are compared with the number of failures, the amount must be very small.
 
A.P.F. said:
This assumes that such activity will cause a hardening of the spring.
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any scientific insight for this ? i really don't see it happening when opening closing the blade. unless you are superman .... the spring is thin but not enough heat generated to harden it ...

an issue that have been reported on a french forum about this is unproper placement of the omega spring after some maintenance. in some models the scales can block the spring and cause faillure.
 
I have had a liner wear out on my M16 it was steel so I prefer Ti for liner locks.

One thing I like about the axis is even if both the omega springs break the knife is not useless. You can jam a stick behind the axis and it will still keep the blade open.
 
Everything will eventually wear out.

I’ve personally only had one knife with a liner lock wear to the point that I had serious blade play, but to be honest it wasn’t from a ton of use. Rather I used the knife kind of like worry beads, constantly playing with it in front of the TV or computer.
 
I have an older type of military and it has some play on the liner lock:mad:.
The blade is still new and never cut anything.
I only flicked it sometimes but not more than other linerlocks.
So never used hard only did some flicking.
I am sure the play wasn't there when i bought it.

Probably a bad heat treat of the liner.
So really a P.O.S. :eek:
I have bent the liner a bit so its still usable but it has some play.
If i had not bent the liner it would not even stay locked with a soft spine wack test.

So some type of wear but not by use over the years but probably bad heat treat.
 
I would describe the Omega spring as experiencing "fatigue".

Not all springs are created equal. It would have been better if the spring was designed coiled inwards so that for the same thumb movement of pulling it back then the nowhere in the spring it will experience as much flex as compared with the current Omega spring design.

That will reduce the flex experienced and significantly increase service life. Theoretically.

True, some have had their omega springs for a while now and no failure, as I said not all springs are created equal.

Back to topic: Another thing to note is the relative difference in the hardness of the lock-tip and the blade tang cutoff. If the difference is too high then wear will be fast for the softer material. That's why I've heard some maker's harden the locktip and some (like for my Lion Steel SR-1) carbide coat (is that correct?) the blade tang cutoff.
 
I am thinking abotu buying a cheap Ruko but my concern is a thin liner lock but judging from some of these posts I dont have alot to worry about.
 
Judging from the posts you have not a lot to worry about all the way to a LOT to be worried about. The only problem is you don't know which you will get. I don't like to gamble so I no longer play.
 
pwet said:
any scientific insight for this ? i really don't see it happening when opening closing the blade. unless you are superman .... the spring is thin but not enough heat generated to harden it ...

an issue that have been reported on a french forum about this is unproper placement of the omega spring after some maintenance. in some models the scales can block the spring and cause faillure.
Click to expand...

Yes, this was an area that I am not sure about. Do the springs suffer from fatique, work hardening or fail as part of a statistical Mean Time Before Failure bell curve. Perhaps any failures are expected as part of manufacturing variables. I just don't know. :confused:

That improper Omegs spring placement after repair does explain a lot of the failures I have read about. Good catch!
 
Most modern locking mechanisms require some form of a spring which can wear out. They also have hard tempered steel bearing on another metal (usually steel or titanium) and this means wear over time.

Nothing lasts forever, but good designs should last very long, and will keep on locking and cutting long after blade-play develops.
 
A couple of guys touched on it, and at the risk of going on a tangent: Do omega springs eventually wear out? I'm new to the Axis lock, so I'm not sure if they'd behave in a similar fashion to, say, an assist torsion bar, which in my experience has only a limited lifespan and will eventually need to be replaced, or if omega springs could be expected to last for a much longer period. Don't mean to derail the topic, but since it's been brought up, I figure this would be as good a place as any to discuss a different sort of lock longevity.
 
A spring is a mechanical device, and as such it will eventually wear out if flexed enough times. Any spring, mind you, not just an omega spring. The spring in a Buck 110 or a Case slipjoint is just as incapable of lasting into infinity as the spring in an Axis lock.

So does that mean only locking designs which don't use springs (like the Opinel) are safe and secure? Of course not. Everything's a compromise.
 
Cotherion said:
I have had some observations.

Liner locks (LL) like my military (spydie) has taken a lot of opening/closing and wear is not noticable. LL like a custom I own has worn out.

Frame locks (FL) like my ZT300 (2nd hand and lockup is still the same) but my CRKT Drifter is at 100%.

What do I mean?
I think it's got to do with the blade tang cutout's profile. In the Mille, the cutout is curved making wear resistance exponentially (not really exponentially but it describes it being more than linear) increasing as it travels due to the contact surface becoming more and more inclined from the perpendicular as it wears.

Straight cutouts wear faster in my observation. Perhaps due to the arc of the lockbar's locktip (imagine it's movement with the relief as the pivot point) resulting it moving further away from the cutout as it wears = less wedging type force.

Just a thought, may not be entirely accurate, but holds true for all my folders.
Click to expand...

Same here. The only knife I've had wear out was a Mission MPF 3 purchased new from Mission for $415.00 that started having lock problems within 1.5 years of EDC. The tang didn't have hardly any angle cut in it but was almost straight across. Tried to talk to the new owner at Mission an explain the problem, didn't get it, not one bit.

Have a TNT with a very visible angle on tang and lock is about 35% and have used it heavy for a while and it is still the same, the lock on that knife is awesome.

So basically my observations match your to the letter for the most part it has to do with the angle at which point the tang comes into contact with the lock bar face is cut.
 
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