Which Lock is Most Resistant to Impacts?

[gnlw]

Compression lock? Lockback? I would think that since the Chinook series and Yojimbo series are designed for MBC and utilize these locks, that they would be the most impact-resistant. Also, the Police 3 has such a strong lock spring that its lockbar should not bounce during impact. Just wondering. What do you guys think?

[dialex]

I can testify that my wife cracked open some coconuts with the spine of her Chinook (I'st generation, S60V). The knife still has no bladeplay.
And the Youtube is full of Paramillies tortured with all sort of lock tests. Surprisingly, the knife holds better than one would expect :)

[Blerv]

Model > Lock Type.

[The Deacon]

Any and every lock can be defeated. Some may take more effort than others. Some may resist one specific attack mode better than another, but be on the low end of the scale for a different attack. Some will be more subject to being unlocked unintentionally due to grip changes. And, ad Blake said, make and model are more important than lock type. IMHO, if you are engaging in an activity where resistance to impacts is a concern, whether that means resistance to bouncing, resistance to breaking, or lack of opportunity for accidental release, the simple fact is that you should not be using a folding knife - period.

[Blerv]

The act of lock failure is quite rare, let alone injuries due to it. With the amount of macro photographing folks out there I'm sure safety concerns would be broadcasted from megaphones.

If in doubt go past your need by a step or two. As Paul said its hard to beat a good fixed blade :) . There isn't a Spyderco folder I wouldn't trust for my needs though. My hands are too feeble to break one.

[Pockets]

I agree with the fixed blade. Also, knives made by Spyderco :D

[Cliff Stamp]

IMHO, if you are engaging in an activity where resistance to impacts is a concern, whether that means resistance to bouncing, resistance to breaking, or lack of opportunity for accidental release, the simple fact is that you should not be using a folding knife - period.

Then what are locks for exactly?

[Minibear453]

While I agree with the Deacon, I think it's only if the knife is expected to endure repeated impacts. For me, a lock is for situations where you accidentally hit the spine or something. Maybe in a SD situation, the knife gets whacked with a flailing arm. If I were to smack on the spine of a knife, I would use a fixed blade. Light impacts I would be okay with. However, this is coming from someone who used his Endura to baton through countless logs during a snowcamping trip. That knife allowed us to reach the dry wood inside, and allowed a fire to be lit. I batoned it with the lock disengaged, heard from somewhere that you should disengage first and then baton, so that there's no stress on the lock.

More on topic, I've always thought that a compression lock would give way to wiggle pretty quick, since every time the spine is hit, the lock bar is squeezed between the pin and the tang, which would compress it? One of the liner locks I've made, I was slashing wood, when I decided to try a back cut for fun, and the lock went from 20 to 80%. Hammered a stop pin into my second hole, and tried it again, but this time, the lock stayed at around the same percentage. Figured the titanium compressed during the first whack, but was already compressed for the second. No idea what happened though.

[JD Spydo]

I do agree that in a demanding situation of using a knife for very demanding chores you would be much better off with a well built fixed blade knife over a folder.

Just about every survival manual and book I've read prefers fixed blade knives over folders for demanding cutting chores. Safety being the main factor obviously but it just makes good sense all the way around.

I wouldn't use even Spyderco's best folder or best locking system for a cutting job where an injury might result in a failure.

Also using a fixed blade knife for demanding jobs I would add that it should also have a full tang as well.

[chuck_roxas45]

Then what are locks for exactly?

Plus 1...

[The Deacon]

IMHO, if you are engaging in an activity where resistance to impacts is a concern, whether that means resistance to bouncing, resistance to breaking, or lack of opportunity for accidental release, the simple fact is that you should not be using a folding knife - period.

Then what are locks for exactly?

To prevent unintentional "folding" when you maintain pressure on the spine between cuts or withdraw the blade from a cut and to decrease the chance of it when you unexpectedly bump the spine against something.

[Cliff Stamp]

To prevent unintentional "folding" when you maintain pressure on the spine between cuts or withdraw the blade from a cut and to decrease the chance of it when you unexpectedly bump the spine against something.

Isn't that in direct contradiction to your first statement?

"IMHO, if you are engaging in an activity where resistance to impacts is a concern, whether that means resistance to bouncing, resistance to breaking, or lack of opportunity for accidental release, the simple fact is that you should not be using a folding knife - period."

I don't see the distinction between the two. As well I don't see how it can even be called a lock by definition if it isn't supposed to be used to withstand forces which act to disengage it - that is what a lock does by definition, even the simplest of locks has to have extreme stability and moderate strength.

Just consider for example the lock on the front door to your house, you can buy these as cheap as $15. Now go buy one, install it in a temporary door and see how much work it is to actually make it release without actually breaking the mechanism and then see how much it takes to break the mechanism. In almost all cases it is easier to break the door around the lock than the lock itself.

I don't see why you would expect so little out of a lock on a knife because there is no way you would tolerate locks in general which would be instable under minor jarring. In fact you seem to be treating the locks on folding knives as safety which is completely different than an actual lock in both design and function.

Now you are free to make such decisions but it is a curious thing to accept instability in locks when with proper design/manufacturing it should not be an issue and what you are doing at a basic level is simply accepting sloppy workmanship.

As a general rule, a lock should never release by accident. It should only release intentionally, or when it has been loaded to the point that it simply breaks due to mechanical failure of the parts. If the parts actually disengage then it was not designed or manufactured properly because it could not keep the forces properly directed. This is basic fundamental of lock design.

[chuck_roxas45]

Isn't that in direct contradiction to your first statement?

"IMHO, if you are engaging in an activity where resistance to impacts is a concern, whether that means resistance to bouncing, resistance to breaking, or lack of opportunity for accidental release, the simple fact is that you should not be using a folding knife - period."

I don't see the distinction between the two. As well I don't see how it can even be called a lock by definition if it isn't supposed to be used to withstand forces which act to disengage it - that is what a lock does by definition, even the simplest of locks has to have extreme stability and moderate strength.

Just consider for example the lock on the front door to your house, you can buy these as cheap as $15. Now go buy one, install it in a temporary door and see how much work it is to actually make it release without actually breaking the mechanism and then see how much it takes to break the mechanism. In almost all cases it is easier to break the door around the lock than the lock itself.

I don't see why you would expect so little out of a lock on a knife because there is no way you would tolerate locks in general which would be instable under minor jarring. In fact you seem to be treating the locks on folding knives as safety which is completely different than an actual lock in both design and function.

Now you are free to make such decisions but it is a curious thing to accept instability in locks when with proper design/manufacturing it should not be an issue and what you are doing at a basic level is simply accepting sloppy workmanship.

As a general rule, a lock should never release by accident. It should only release intentionally, or when it has been loaded to the point that it simply breaks due to mechanical failure of the parts. If the parts actually disengage then it was not designed or manufactured properly because it could not keep the forces properly directed. This is basic fundamental of lock design.

That's the best explanation of a lock's purpose that I have seen since I have been on the forums. Well written Cliff.

[Blerv]

Threads like this are often intrinsically linked with abuse of locks (eg: hammering with the spine) instead of as an accidental closing aid.

If someone asks which lock will take impacts the best my assumption is either they don't realise how strong Spyderco locks are or they do but plan to push the limitations. If the latter, they shouldn't be using a folder.

[The Deacon]

Isn't that in direct contradiction to your first statement?

"IMHO, if you are engaging in an activity where resistance to impacts is a concern, whether that means resistance to bouncing, resistance to breaking, or lack of opportunity for accidental release, the simple fact is that you should not be using a folding knife - period."

I don't see the distinction between the two. As well I don't see how it can even be called a lock by definition if it isn't supposed to be used to withstand forces which act to disengage it - that is what a lock does by definition, even the simplest of locks has to have extreme stability and moderate strength.

Well Cliff, it may seem contradictory to the snippet of my original post you chose to quote, but I do not see it as the least be contradictory to my first post. To me, there's a world of difference between something which augments stability and provides moderate resistance to accidental closure and something meant to withstand severe and repeated impacts.

[Franco G]

I think, Cliff understand a lot about locks since he tested many lock systems.

BTW, Cliff, where are your reviews - I lost links - I would appreciate if you could help?

[thelock]

They can all fail on strong impact, I have even had the tri-ad lock fail once and that is the strongest lock out there.

[Ed Schempp]

Spyderco make a wide variety of locks and knives. My experience it that they do the best they can on every knife and every lock.

Locks are like people, it isn't whether or not you can trust them but how much them. I don't see a line but a wide grey area...Take Care...Ed

[SolidState]

Breaching 101: A door is not a wall, even if it locks.

[Cliff Stamp]

They can all fail on strong impact, I have even had the tri-ad lock fail once and that is the strongest lock out there.

It isn't that they fail that is the issue, it is how they fail. Similar to all edges blunt, but how they blunt is critical in determining for example if the steel was hardened properly.

I would appreciate if you could help?

http://www.cliffstamp.com/knives/reviews/reviews.html

They are in severe need of updating, especially the summary pages but I would rather work with knives that edit. I will get around to it the winter most likely when we start getting heavy sleet.

Threads like this are often intrinsically linked with abuse of locks (eg: hammering with the spine) instead of as an accidental closing aid.

Go to a junkyard, lock the door on a car. Now subject the door to whatever impacts you want and try to get the lock to release, see how easy it is to do without damaging the car (and not using special equipment made to release the lock). Take a $2 padlock and get into it with a hammer, even the cheapest ones take pretty large forces to jar them apart and by the time you spend $20 for one you can forget about it.

The simplest criteria is this, if someone gives you a knife and the lock has released by accident and the knife is still in mint condition then the lock was poorly made or designed. However if the face of the lock bar was compacted, if the handle scales are broken/bent, if the back spring it warped etc. - that lock was designed properly. Both may be abused but one still is defective.

Just consider this, if I was to drop a Spyderco Kitchen knife on a ceramic floor that is obviously abuse and the tip could be impacted, even slightly broken (depending on angle of impact), or the edge could be dented/chipped. But if the knife snapped in half, if the handle popped off etc. - could that be excused by saying "the knife was abused"? No, no one would argue that, everyone would say something was wrong because how it failed was unreasonable.

To me, there's a world of difference between something which augments stability and provides moderate resistance to accidental closure and something meant to withstand severe and repeated impacts.

To be clear, no one is arguing that locks should be made to withstand repeated heavy impacts without limit without damage. The argument is that properly made locks break before they release is it how locks are designed.

Now the curious point is that you know that locks which are properly made have this behavior so why would you accept it otherwise, you certainly would not except it if other aspects of a knife showed the same tolerances.

If for example the HT on a knife was off and it was over soaked and the edge would therefore burr readily in sharpening, and chip very easily in use. Would you just accept that or would you want to have a knife which was HT using proper design protocols such as minimization soak time to dissolve alloy content and prevent grain growth?

If you would accept sloppy design everywhere, ok that is consistent, odd but consistent. But if you don't, then that is a curious case as to why?