How tightly should a folder's blade be held closed?

May 2, 1999
Great strength is desirable to hold a knife open, but what about closed?

I have designed a lock that will be quite strong and impossible to have an accidental failure with, as opposed to breakage under extreme force.

The only thing is, at present and discounting any possible refinements in the future, is that there is no mechanism to keep the blade closed other than the friction of the pin and bolsters.

I know that several locks, such as linerlocks, don't have a whole lot of tension against the blade to hold it closed.

So how big of a deal is this? Obviously I should like to refine this lock further, but is it neccessary?
A lot of liner locks are as you describe, but I consider that a serious flaw. Pocket-opening is real enough that it's worth guarding against it. It doesn't take too much to do so. The ball/detente setup if done really well works fine, though I'd rather have something a little stronger.

What I'd suggest is this. Take your folder, stick it in your waistband, and head to jiu-jitsu class (or whatever). If the blade doesn't open, you're good to go.

With lockbacks as you describe above, it doesn't seem too big a problem. Also, there are some folders that lock closed too. (I believe the GT Knives folder's button lock works this way, for example).

I'm not sure, but it seems that with a linerlock, the risk of accidental opening may be even greater with a larger knife.
I always check a knife by grasping it at the butt end with the blade closed and the spine up and giving it a downward jerk, trying to pop it open. If it opens, I do't want it.
I've had POS linerlocks open in my pocket, and it aint comfortable!
Judging by other posts some like to be able to flick them open for fast deployment.
I'd rather not experience a puctured femoral artery.
Hey Snick,
Autoknife locks would fit the bill. It would stay shut until you pressed a button. Like a Boker Toplock. I can take a pic of a taken-apart one if you are unfamiliar with the mechanism on the most common ones. They are pretty simple. Plus, if you added a spring...

Stray, yeah I'd like to see that picture if you could get it up, or e-mail it to me if that's easier. The lock itself is very solid open, but closed is another matter. At present.
OK Snick, click here. The choil-looking part of the blade catches the spring loaded plunger/ push button and holds it closed. When the button is pressed the blade bypasses the skinny part of the plunger and opens.

Thanks! That was a good bit more informative than I thought it would be, so I saved it.

But unfortunately I don't think that was the answer I am looking for. I'll have to play with the concept...
Snick, I think that it is important that the knife stay in the position that you want it to be in, either open or closed. I would consider this a major factor in designing a new lock type.

Can't wait to see what you come up with.

How tight is a matter of personal preference and will depend on how you carry and use the knife.

If you carry tip down (as God intended folders to be carried), with a pocket clip or in a sheath, then they can be quite loose. I like mine fairly loose. Keep in mind, though that to loose will compromise a liner-lock's ability keep it open.