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Lock comparison

Posted: Sun Apr 15, 2012 4:56 pm
by Rayo
What is the difference between a liner lock and the compression lock?

Posted: Sun Apr 15, 2012 5:03 pm
by 2cha
In a liner lock and Reeve integral lock, the lock arm props up the front (cutting edge) of the blade tang. Most of the force of stabbing is resisted by the pivot pin. In a compression lock, the lock arm wedges into a slot on the bottom of the blade tang between a support pin and the pivot pin. IMO the compression lock is far superior.

This metaphor sort of works. Think about front door of your house. liner lock is a little like putting a wedge under the door whereas the compression lock is like putting a wedge between the leaves of the hinge--there is continuous contact and door can't close unless the wedge is squished.

Posted: Sun Apr 15, 2012 5:05 pm
by jackknifeh
The difference is they are not the same. Lol. I crack myself up.

Seriously, I've only held a knife with a compression lock for about 5 minutes and am not knowledgable enough to explain it. Others will though. There are pictures of different locks used by Spyderco in the edge-U-cation portion of a catalog or on the web site. They are kinda sorta similar but one is on the top and one is on the bottom.


Posted: Sun Apr 15, 2012 6:05 pm
by JNewell
This is one of the picture-is-worth-ten thousand-words situations. :o One practical way of thinking about it is that a linerlock or framelock will fail if enough pressure is applied to the spine of the blade to flex or collapse the locking leaf or bar. Failure of the compression lock requires that you either shear the stop pin, or crush the locking tab between the blade tang and stop pin, or force the stop pin and fasteners out the back of the liners, and I will point out that at least in the Para2 the stop pin is recessed into both liners, further strengthening the stop pin. None of this means that a well designed and well manufactured linerlock or framelock isn't stronger than any normal person needs for any reasonable knife use, though. It should be mostly academic. :)

Posted: Sun Apr 15, 2012 6:10 pm
by Evil D
Props go to David Lowry for this pic. The lock tab wedges between the stop pin and the tang, whereas a liner lock only wedges against the tang.


Posted: Mon Apr 16, 2012 5:25 pm
by Rayo
Thanks forum for the great input.

Posted: Mon Apr 16, 2012 6:05 pm
by jackknifeh
The picture of the para2 compression lock is great. You can look at it and understand why it WON'T close with out being released. Talk about creating trust. I got the same level of trust when I took my Manix2 apart and could see exactly how the CBBL keeps the knife from closing unless released. I'd love to have a few pictures of each lock like the one of the para2. The pictures in Edge-u-cation are ok when all you need is 2 dimensions. With a liner, frame and compression lock you need a picture to show depth also because that is the direction the lock bar moves. With David Lowry's picture shown by Evil we can see how it works.

I'd like to ask anyone who can to provide pictures of their knives when disassembled to illustrate the lock design. I'd be happy to try with my Manix2 and Gayle Bradley but my camera may not be good enough to show enough detail. The only other lock I have is the back lock and I haven't taken any of them apart. I don't want to take a knife apart just to take a picture of it. I plan on taking my GB and Manix2 apart in the future for maintenance so I can go ahead and do it now to get the pictures. You can easily see how a liner lock works just looking at it without taking the knife apart. Not so easy to see with the Manix2. If anyone else can get pictures like the one above we can put all of them in a thread. I know there is a great picture of the Chaparral disassembled showing the lock on the forum. That's a great one to show because of the stop pins on the tang and grooves in the liners for it. I think this is the first knife Spyderco used the design on. I'm not positive though. It is also on the Sage4. I don't see any need to disassemble a Sage4 if it is the same as the Chaparral, noy MY Sage4 anyway. :)

If people could take pictures when they have a knife apart I know I'd appreciate it and I think others would as well. I'm not suggesting anyone take a knife apart just to take a picture. Also, TAKING A KNIFE APART WILL VOID THE WARRANTY! I'll put the Chaparral picture here since I already have it. You can see that in addition to the back lock stopping the blade the stop pin stops it as well. I think this is to reduce or eliminate vertical blade play from developing over time. I wish there was a picture of the blade open without the liner.


Posted: Tue Apr 17, 2012 3:59 pm
by Sonny

Posted: Tue Apr 17, 2012 4:14 pm
by 2cha
jackknifeh wrote: I'd like to ask anyone who can to provide pictures of their knives when disassembled to illustrate the lock design.
It's also interesting to look at the patents for different locking mechanisms. Links to many patents can be found by searching this forum.

Posted: Tue Apr 17, 2012 4:33 pm
by TazKristi
If you scroll down a bit you'll find complete descriptions and illustrations of all of our locking mechanisms here...


Posted: Tue Apr 17, 2012 4:38 pm
by sal
Hi Rayo,

Welcome to the Spyderco forum. Lots of very knowledgable folks here.


Posted: Wed Apr 18, 2012 6:28 pm
by Rayo
Thank you Sal and Taz for a great forum and a ton of useful information.


Posted: Mon Jul 23, 2012 5:18 pm
by GringoFusilero
Hi all. New to the forums. I did a quick search for this because I was curious myself... The compression lock on my new PM2 kinda looked like a backwards linerlock.

THANK YOU Evil D for that picture! Crystal clear now. And yeah, the compression lock seems much stronger. Thanks again. And thanks Sal for making such a terrific knife! My Delica has served me well for years but I thought it was time for an upgrade. Couldn't be happier with my Paramilitary 2!