What lock wears out fastest?

[singularity35]

Of all the common types of locks like liner, back lock, frame lock, axis, CBBL, Tri-ad, etc., which do you think wears out the fastest?

 

[Ken44]

Have no idea, but don't think any of these would wear out in a lifetime if its constructed well, and made by a good manufacture such as Spyderco, BM, CRK etc..

 

[singularity35]

Have no idea, but don't think any of these would wear out in a lifetime if its constructed well, and made by a good manufacture such as Spyderco, BM, CRK etc..

I'm sure of that, but inherently from an engineering standpoint or design standpoint, they can't all be equal.

 

[Planterz]

Liner and frame locks will wear the quickest. Of course, this depends greatly on the materials and manufacture quality, as well as usage/abusage (ie: spine whacking). But the fact is that there's friction to over come each time you engage/disengage a frame/liner lock, which causes wear. And of course, every lock has some sort of friction when engaging/disengaging, but other locks are less affected compared to liner/frame locks, or not affected at all.

Liner and frame locks, by their very nature, will also be made from softer materials. Blades are obviously hardened steel, and the stop pins, lock bars, etc of other locks will also likely be hardened steel. But a liner or framelock will either be a springy steel or titanium, which will always be softer, and thus wear more quickly.

 

[TTTis]

There are far far far too many variables to put a broad stroke over all the lock types and determine which would wear the fastest.

 

[FlaMtnBkr]

In my experience liner and frame locks wear out much faster than others. Or at least have the potential to do so. Some liner locks may last a lifetime while another, even on the same model knife, will wear out in a year. And you have no idea what you are going to get. Once they wear out they have to be thrown away because there is not much that can be done.

I had a frame lock knife from one of the most popular production companies wear out in less than a year with minimal use. Now the lock hits the other scale and there is a ton of blade play.

I have had others that fail without warning and unlock during use. Probably half of the liner locks I have owned have failed in some way and were all $50 to $100 knives. I now try to avoid them and rarely buy even titanium frame locks. It has to be a great design for me to purchase one. The Gayle Bradley was the first I have bought in a long time and will be the last at least for the foreseeable future.

 

[Kyui Su Kim]

I would have to put my vote in for the liner locks as well. Personally, I have yet to have my other locks wear out but have had 2 or 3 liners that began to shows signs of "vertical" play due to wear. With that said, I have never had a quality knife with a liner lock "fail" yet.

 

[stabman]

Liner, absolutely (in most cases).
The only reason most frame-locks don't wear as quickly is due to a larger lock-bar/tang interface.
If the lock-bar is the same thickness (thin frame-lock or thick liner-lock), then the wear rate will be the same, assuming the same tang angle.
AXIS lock and lock-back will go on practically forever if the springs stay good.

 

[MikeC]

Stabman, "assuming the same tang angle" Huh??????????

The lock bar face must be flat (no angle) or since it is vertical then let us say 90 degrees, the angle cut on the tang must be 10 degrees to 12 degrees to the makers I've spoken with. If the lock bar face and tang are cut at the same angle then there will be no material to provide resistance the lock bar will simply travel all the way over the non locking handle slab upon engaging the lock (opening the blade).

THE ENGAGING AND DISENGAGING OR OPERATION OF ANY LOCKING MECHANISM IS GOING TO CAUSE FRICTION. CRK heats up the end of the lock bar face which is titanium on the sebenza and makes it very hard through this process thereby increasing its hardness to something similar of the blade material S30V, so far so good, I know people who have 13+ year old sebenza's that are EDC'd and still have solid, functional, and safe locks and its a frame lock. There are way too many variables here, and most frame locks are cut with a tang angle of 10 degrees for safety reasons, however I have been told if you take it to 12 degrees locks would last longer.

 

[chanwahyaoh]

I think that wear will depend more upon the engineering & materials of the lock than it would the lock type.

 

[AF]

Some liner locks may last a lifetime while another, even on the same model knife, will wear out in a year. Once they wear out they have to be thrown away because there is not much that can be done.

Do manufacturers generally not replace a worn liner if returned? Not covered under warranty?

 

[FlaMtnBkr]

Stabman, "assuming the same tang angle" Huh??????????

The lock bar face must be flat (no angle) or since it is vertical then let us say 90 degrees, the angle cut on the tang must be 10 degrees to 12 degrees to the makers I've spoken with. If the lock bar face and tang are cut at the same angle then there will be no material to provide resistance the lock bar will simply travel all the way over the non locking handle slab upon engaging the lock (opening the blade).

THE ENGAGING AND DISENGAGING OR OPERATION OF ANY LOCKING MECHANISM IS GOING TO CAUSE FRICTION. CRK heats up the end of the lock bar face which is titanium on the sebenza and makes it very hard through this process thereby increasing its hardness to something similar of the blade material S30V, so far so good, I know people who have 13+ year old sebenza's that are EDC'd and still have solid, functional, and safe locks and its a frame lock. There are way too many variables here, and most frame locks are cut with a tang angle of 10 degrees for safety reasons, however I have been told if you take it to 12 degrees locks would last longer.

Various alloys of titanium only respond slightly to heat treatment meaning they only gain a couple points on the Rockwell scale. If I remember correctly titanium runs around 35 on the Rockwell scale and if heat treated can run around the low 40s depending on alloy. This is still significantly softer than any blade steel and is probably part of the reason titanium galls. The low hardness is also why titanium makes a poor blade material. The toughness of titanium might make up for it's lack of hardness some, but I would think a hardened steel lock would last quite a bit longer than ti. With hardened steel you have to start to worry about wearing the blade tang which is probably why some makers put a deposit of carbides on the tang contact area. I would think a deposit of carbides on the titanium lock would also significantly increase wear resistance but not sure if anyone does that.

 

[FlaMtnBkr]

Do manufacturers generally not replace a worn liner if returned? Not covered under warranty?

I would think most good companies would replace a worn lock bar although a lot of companies only cover defects and not normal wear and tear. But if the company no longer exists there is nothing that can be done. I like to work on things and fix them myself, and you can't add more material to the lock bar. You have to rely on replacing the lock if you want the knife fixed right.

 

[MikeC]

Various alloys of titanium only respond slightly to heat treatment meaning they only gain a couple points on the Rockwell scale. If I remember correctly titanium runs around 35 on the Rockwell scale and if heat treated can run around the low 40s depending on alloy. This is still significantly softer than any blade steel and is probably part of the reason titanium galls. The low hardness is also why titanium makes a poor blade material. The toughness of titanium might make up for it's lack of hardness some, but I would think a hardened steel lock would last quite a bit longer than ti. With hardened steel you have to start to worry about wearing the blade tang which is probably why some makers put a deposit of carbides on the tang contact area. I would think a deposit of carbides on the titanium lock would also significantly increase wear resistance but not sure if anyone does that.

\\

From what I understand that is exactly what CRK does to the lock bar face of the sebenza, my comment was more for the same angle thing, either I just failed to comprehend what he was trying to say are he missed typed or something. Whichever I needed to straighten that out or get him too.

 

[kawr]

Liner, absolutely (in most cases).
The only reason most frame-locks don't wear as quickly is due to a larger lock-bar/tang interface.
If the lock-bar is the same thickness (thin frame-lock or thick liner-lock), then the wear rate will be the same, assuming the same tang angle.
AXIS lock and lock-back will go on practically forever if the springs stay good.

Spring longevity is pretty hard to guess and unreliable. They can go on forever or they can break in a week. I would imagine a lockback would probably last the longest but yeah who knows what can happen with a spring. At least with a liner/frame lock you have a general idea of how much life it has left in it. I think a well done framelock from someone like CRK would last forever. Plenty of people with 10+ year old Sebenzas that are still going strong and likely to last their lifetime and beyond.

 

[FlaMtnBkr]

Spring longevity is pretty hard to guess and unreliable. They can go on forever or they can break in a week. I would imagine a lockback would probably last the longest but yeah who knows what can happen with a spring. At least with a liner/frame lock you have a general idea of how much life it has left in it. I think a well done framelock from someone like CRK would last forever. Plenty of people with 10+ year old Sebenzas that are still going strong and likely to last their lifetime and beyond.

Do you really think spring life can not be approximated by either engineering theory or stress testing? I guess they just throw springs into multi-million dollar military aircraft without having any idea of lifespan where a spring breaking could mean catastrophic failure and loss of life.

As long as the spring is not pushed past plastic deformation it should have a very long lifetime and can be approximated if dimensions and materials are known. There will always be a small statistical percentage that will fail. There have been reports of omega springs breaking but how many have broken out of the hundreds of thousands or even millions of springs that are in service? There have been maybe 20 people that have reported a failure out of the almost 200,000 members of this forum. Statistically that is essentially a zero chance of a failure. I can live with that but it sounds like others can't and must only be satisfied with absolute perfection.

Also, a frame and liner lock can be considered a spring but who has ever heard of the lock failing as if the spring broke. I have never heard of a lock bar just snapping off because it has been cycled so many times. The spring doesn't break but the end wears out which effects tolerances. That is a completely different mode of failure. A well made frame lock may last a lifetime but that is a far cry from forever.

 

[stabman]

\\
either I just failed to comprehend what he was trying to say are he missed typed or something. Whichever I needed to straighten that out or get him too.

Yes, you DID misunderstand.
I was talkiing about a situation where the tang angle was the same on BOTH THE LINER AND THE FRAME-LOCK.
TANG angle, NOT lock-bar face angle.
I thought it was worded clearly enough, and after reading it again, it was.