Are Folders Locking Mechanisms Safe?

[orthogonal1]

More specifically, Torque = perpendicular distance x force.

The force must be normal to a straight line normal to the axis of rotation (unless you want to do more calculations). Normalizing force vectors is one of the first things learned.

 

[cgmblade]

To the OP, too bad you don't have the knife anymore. It'd be nice to learn what the problem was. I've given some thought to how you said you were using the knife when it failed and it sounds like you might have been putting some lateral pressure on the blade. If so that may have contributed to the lock failure.

In any case I think you would agree that the particular knife you were using was a little light for the task. Don't give up on folding knives. The locking mechanisms on good quality knives are generally very secure. I'm sure there are plenty of people here who would be glad to recommend some models. I'd suggest the Spyderco Delica as a great starting point for your collection.

 

[J.Mattson]

Beyond everything that can be said about lock strength we’ve already agreed that any lock can fail.

This is why I like so many designs by Kershaw and Spyderco, they offer good finger protection if the lock should ever fail. I don’t know about you but that counts for me.

 

[unky_gumbi]

I don't see what all the hype about spyderco's lockback is. A friend at work has a spyderco police, and I can rattle the blade in a normal grip, it wont close but it sounds like a babies rattle when shaken. Maybe its not lefty compatable, but I personally don't trust lockbacks in my hands had a few release on me, but luckly never been caught by the blade. I currently have 2 linner locks and an axis lock, the liner locks look flimsy but lock up solid (CKRT M21-04 and a cheap cabelas sawtooth) and I have not had a hint of play in normal use on either. The Axis lock is the one I trust the most, in most of my common grips my finger and thumb actually pushes the lock bar into the blade so not only does the force have to overcome the lock spring but my pressure as well. I would trust a Axis lock "almost" as much as a fixed blade.

 

[GWashington1732]

How are you guys using knives that you're breaking the locks? I have never had a lock fail on me. I closed a liner lock on my hand once by being stupid, but the lock didn't fail, I pushed the liner closed, so what are you doing?

 

[yablanowitz]

Cutting through the tabs on a 5 gallon bucket is harder on the knife than you think. You must apply enough pressure to get the cut started, but once it is started it requires less force to continue the cut. On those short cuts, you don't notice it, but on longer cuts you can feel it. Then, at the end of the cut the sudden release of pressure will throw the blade forward against the lock. If you then strike the side of the pail, that throws another shock through the knife. It all adds up. I knew a guy years ago that had figured out how to get Snap-On to replace his dull side-cutters (the warranty didn't cover wear, just breakage). When they started getting dull, he'd use them to cut some rubber grommets. The shock of cutting through the resilient material and slamming shut would break the jaws in short order.

All locking mechanisms are designed to lull you into a false sense of security. They try to make you forget that the knife you are using is designed to fold up. Once you forget that and start using the knife as if it can't fold, it is only a matter of time until you get hurt. The more you trust that lock, the worse you'll get hurt when it finally fails to protect you from your bad habits.

 

[Hitthespot]

To the OP, too bad you don't have the knife anymore. It'd be nice to learn what the problem was. I've given some thought to how you said you were using the knife when it failed and it sounds like you might have been putting some lateral pressure on the blade. If so that may have contributed to the lock failure.

In any case I think you would agree that the particular knife you were using was a little light for the task. Don't give up on folding knives. The locking mechanisms on good quality knives are generally very secure. I'm sure there are plenty of people here who would be glad to recommend some models. I'd suggest the Spyderco Delica as a great starting point for your collection.

Yea, I wish I would have kept it. I threw it in my gun cabinet for a couple of days and then said,"why am I keeping this?"

Yes the knife was a little light for the task. It wasn't too bright being in a hurry and just using what was in my pocket at the time.

I just bought a Kershaw Mini Cyclone. I cannot believe how much knife you get for $29.00. I seen these for as high as $71.00 on the internet and when I received an email stating they were on sale for $29.00 I just had to jump on it. I should buy 4 more.

Bill

 

[cgmblade]

I just bought a Kershaw Mini Cyclone. I cannot believe how much knife you get for $29.00. I seen these for as high as $71.00 on the internet and when I received an email stating they were on sale for $29.00 I just had to jump on it. I should buy 4 more.

Bill

You can never have too many knives.

 

[cutter17]

This is a topic that seems to come up on a monthly basis. Not complaining as it is still interesting to read and I still learn something new, most of the time. Nothing much to add, but I also have never had a lock fail on me, and even though I have faith in certain locks, done by companies I trust to do them right, I still treat the knife as if it didn't have a lock. Must be a subconscious thing!

 

[unky_gumbi]

How are you guys using knives that you're breaking the locks? I have never had a lock fail on me. I closed a liner lock on my hand once by being stupid, but the lock didn't fail, I pushed the liner closed, so what are you doing?

I think that the problems I have with lockbacks is just my grip and hand don't mesh well with them. I tend not to be hard on knifes, and have never had a problem with any other type knife, even slipjoints. I think the heaviest use I have ever put a folder through was making shavings for a campfire