Is liner lock that bad?

[tomcrx]

I think because on a frame lock, when you squeeze or grip the handle, you are preventing the lock to slide to the open position. The harder you grip, the more pressure against the lock. On a liner lock, your grip isn't reinforcing the lock because it's not touching it.

That is a double edge sword too. The ability to touch the lock also gives you
the ability to unlock it by mistake in twisting cuts or when the hand slips .No lock is 100% safe

 

[golden chicken]

funny. 80 posts and no mention of LAWKS or Auto-LAWKS? seems to me like a good way to add security to a liner lock.

i also want to mention that on my CRKT crawford/kasper, where the liner rests against the back of the blade, the back of the blade is machined very close to perpendicular. my kershaw tanto blur is kind of angled. angled the wrong way. it would seem, though i have not attempted it, that sufficient pressure on the spine of the blade (or enough pressure while sawing) would drive the liner right out of the way like a wedge.

 

[Dekz]

Thanks, the Moderator STR summed it up very well on the second page of the thread.

That's probably the first time a post by STR has been considered a summary (they are usually rather lengthy )

my kershaw tanto blur is kind of angled. angled the wrong way. it would seem, though i have not attempted it, that sufficient pressure on the spine of the blade (or enough pressure while sawing) would drive the liner right out of the way like a wedge.

Almost all liner/frame locks are angled like that. And while at first it may seem to be the "wrong way", it isn't. This angle exists so that the blade will still lock up tight as the liner wears down over time/use.

 

[Joshua J.]

I think it's also important to note that a thicker lockbar will be more stable under pressure.
When you apply pressure to the back of your blade, you compress the lockbar. When you do a pressure test on a liner lock you can usually see the lock flex, IMO this is one of the things that helps the lockbar "jump" off the blade tang when it gets a sudden shock.
While a hard shock can probably disengage any lock, a stiffer (thicker) lock bar should make it less likely.

 

[golden chicken]

Almost all liner/frame locks are angled like that. And while at first it may seem to be the "wrong way", it isn't. This angle exists so that the blade will still lock up tight as the liner wears down over time/use.

so....are you suggesting that as the liner gets shorter from wear, it also bends further into the space between the handles and the angle is to keep a flush interface?

it seems to me that a liner's "spring" inwards would become weaker as it wears as well, wouldn't it?

 

[knerd]

so....are you suggesting that as the liner gets shorter from wear, it also bends further into the space between the handles and the angle is to keep a flush interface?

it seems to me that a liner's "spring" inwards would become weaker as it wears as well, wouldn't it?

Yes they get weaker after time. You can also remove the lock side and bend the liner/frame in more so there's more tension if you ever feel your lock is getting weaker.

 

[ginshun]

A few people have commented on the frame vs liner lock debate and said that the frame lock is only as strong as the thinnest part, the frame cutout. While this is true, it doesn't mean a frame lock with a .125 thick lockbar and a .05" thick cutout section has the same strength as a linerlock where the whole lockbar thickness is .05". Since the lock bar on this type of lock is loaded in compression, the failure would be by buckling. Since this is the case, the length makes a difference, so the framelock, with its short little section of .05 thickness will be stronger. Think of it as if you were trying to make a piece of wire fail by pressing on the ends. If you have a 12" long wire about the diameter of a paper clip, its pretty easy to make if bend just by pressing straight in on the ends, not trying to bend it as all, because it will buckle. By contrast, its pretty hard to make the same diameter wire bend by this method if it is only a 1/4" long. Same type of deal with the liner vs. frame lock.

Its all academic really though, because if you are putting enough pressure on either lock for it to fail via this mode, then you're a retard.

 

[orthogonal1]

I think it's also important to note that a thicker lockbar will be more stable under pressure.
When you apply pressure to the back of your blade, you compress the lockbar. When you do a pressure test on a liner lock you can usually see the lock flex, IMO this is one of the things that helps the lockbar "jump" off the blade tang when it gets a sudden shock.
While a hard shock can probably disengage any lock, a stiffer (thicker) lock bar should make it less likely.

There is some merit to that theory, but remeber the first Military knives?

The locks on some of those, all the ones I've handled, were rather flexible. I call mine "flexy flyer". Yet, these knives generally pass testing - mine does.