I just completed a liner lock folder which has .050" Titanium liners, an ATS34 blade, and a 9 degree angle on the lock surface. This is about the 10th folder I've made and it has a problem the others haven't -- the lock sticks. When I push the lock bar to the side to close the blade, it's like it's stuck to the lock surface. I have to push hard until it lets go with a distinctive CLICK! sound. The fit and finish on this knife are the best I've made yet, and the lock is right where I want it. Any ideas on how to fix this would be greatly appreciated as this one is a Christmas gift for my Grandfather and I'm running out of time.:confused:

There was a rather lengthy discussion on this subject some time back. The Search button should help you find it. Many knowledgeable people offered numerous methods of dealing with the problem you describe. This is my way of dealing with it:

1. It's possible that there is some flex in the lock bar and it is pressing too hard agaist the lock notch. You can relieve the pressure by removing a tiny amount of metal from the rear of the blade where it meets the stop bar.

2. I have seen this problem when I don't finish the lock notch surface or the front of the lock bar to a fine finish. Also, I have seen this problem when I do finish those surfaces very well so I really don't think the problem comes from a rough finish. But, if your finish is rough then polishing it up a bit may remove just enough metal to fix the problem.

3. My favorite way to deal with the problem is also the simplest way. With the blade NOT sharpened (and it shouldn't be sharpened until you are satisfied the knife is finished, and right now you aren't) snap the knife open hard so that you know the lock is sticking. Turn the knife over and strike the back of the blade near the tip against the edge of a heavy wooden work bench VERY hard. This will try to force the blade to close and forces the mating surfaces of the lock to conform more perfectly to each other. Incidentally, it also tests the strength of your lock, your lock geometry, and even the heat treat of your blade. :) If this does not solve the problem go back to step 1 and remove a little metal. ....

I think that the angle you filed on the lock is to acute. IMO, you need less of an angle.

A.T.

I tried a search for this subject before I posted this thread and didn't find anything. Probably putting in the wrong words. Anyway, thanks for the suggestions. Ray, I've tried hitting the back of the blade while locked open, it helped a little and I hope the rest of the stickiness will go away with use. I'm afraid to take any metal off the lock surface because the lock bar lines up perfect right now and I'd hate to mess it up. A T, I've heard of makers using anywhere between 7 and 12 degrees of angle on their locks. I'll take your advise and try a bit less angle on future knives.

I'm afraid to take any metal off the lock surface because the lock bar lines up perfect right now and I'd hate to mess it up.

If you work the action 200 or so times, and it's still sticking, then use the file. When you say "the lock bar lines up perfectly now" I assume you mean the lock is flush with the tang of the blade. It won't hurt for the lock to be past the tang a little bit. Tom, a careful swipe or two with a file can do wonders.

IMO, you don't send out a knife that has a sticky lock.


A.T.