What would you

gunfiter

gunfiter

Joined
Apr 17, 2006
Messages
351
Since the search function is down, and frankly I'm to lazy to scroll back and back, I think I'll just ask. I read your opinions on liner locks and some other topics herein. If you were going to design a hard use folder, what blade steel and lock type would you use? When I say hard use, I refer to the fact that I use my knife as a tool almost as much as a knife. Prying, twisting, digging, pulling. I know it's wrong, but when my hand reaches for a tool, my knife is usually the first one it finds.

My ideal blade so far is 3.5-4", spear point, non-serrated, and one hand closeable.
 
That kind of knife that is going to be used that way is going to break. Eventually from prying or using the blade as a screwdriver or diggging with it you will chip it or break the point off when stressed too far or when you hit something solid in the dirt like a big ole rock.

With the shear number of S30V and D2 blades I've repointed for folks over the years I'd suggest avoiding those steels unless they are thicker at the point and obtuse at the cutting edge otherwise you'll likely snap them and chip out big chunks of steel using it like that since most guys I've fixed them for have not even done that much with them and done damage.

I'd go with 154CM steel if you are going higher end. If not a good 440A or 420HC are good and tough and rust resistance is good or one of AUS steels would be my choice over anything else. AUS6 or 8 would be very good and very tough.

Truthfully listening to your use descriptions I sit here thinking to myself of your perfect fit folder. It sounds like the Tarani 5.11 Investigator Lockback was built just for you. I just had one mailed to me recently to go over for a customer and it should still be on page one or just flipped over to page two.

The blade on this one is 154CM steel which is a fine choice. The blade has an ambi one hand opening thumb stud. Its not all that expensive of a folder to replace the knife for when you break it or lose it and its readily available. Its got a great lock, a great grip and handle ergonomics, tip up carry, a nice combo edge and thick point and edge profile.

I'd almost bet money on it that if you get one I'm sure it'll will take what you dish out to it and you'll love it. About the only complaint you'll hear on that one is the distinct half stop feature Tarani designed into the folder but it can be ground off to make it roll around smoothly if it bugs one that much. Its there for a reason according to Steve though, and thats so you have a built in preventive for the blade snapping shut unnannounced on your fingers or gloved hands before you can get them out of the way. the half stop works more strongly on the close than the open and you barely feel or notice it that much opening the folder compared to shutting it.

After having used it for a week I find I actually like the feature and miss seeing it. Used to be in the old days when lockbacks were first being offered that you saw this more often than not but then when the one hand opening thing came around with a pocket clip well, it all had to go I guess. Good luck finding your folder.

I think a good frame lock or stout lockback would be fine. If you want high dollar the best one for you probably would be the Fulcrum II by Extreme Ratio.


STR
 
Oh and I might add this while I am thinking about it.
One of the big reasons folks love the liner lock is the for the strength. They are usually convinced its superior in strength to that of a lockback and the reasoning is usually associated with a static load test they saw or heard about where a liner lock held more weight before it defeated than a lockback or some maker or manufacturer gave the liner lock the stronger rating.

This is deceptive for one reason and its an important one. A static load test is not real world. It cannot duplicate the kind of stress the locks will endure when in the human hand and does not take into account the twisting sideways torques that can also take place during a straight force use with spine pressure and its these sideways forces in conjuction with twists that take all that static load strength and throw it out the window with the trash.

These tests of static load strength are worthless once you take these other forces into account. The lockback may not take the same load in a static force test before the lock face shears but the forces required to do that are much greater than you or I will ever muster in most cases, with the exceptions being one that was made faulty or had a stress riser point built into the lock contact that allowed it to break easier. Faulty heat treatment or just bad steel can all play into why this can happen but truthfully I've not seen one report of it ever happening in use, only in testing. My point is that the lockback does not need to take that kind of shear strength static load to be both strong enough in the hand and reliable in normal use when in your hand. This is where the lockback shines. In twisting sideways torques and straight, vertical or hoizontal stresses to the lock it holds up and works unaffected by those other stresses and more importantly its noteworthy that the lockback works in the hand where its going to be used.

For years folks knew the liner lock was strong. Yet all these reports kept coming back from users about how the darn things failed in use and bit the owners terribly. Many guys were caught scratching their heads about how this happened until it all came together. Its those lateral stresses combined with twists that negate any static strength it might have. When you combine this with the fact that many blades are in use out there with loose pivots and many are done this way by choice for many reasons, one I hear a lot is 'it Waves open easier that way', well it just adds to the ease with which these lock types show signs of weakness in normal uses.

What loosening the pivot does is allow side to side blade play to take place from just normal use and it just adds to the ease with which these sideways motions allow the blade to move along the lock so the lock does not stay put in one place on the blade contact at all. When you have a lock all over the place on the blade in use its a recipe for an easier lock defeat. Thats the bottom line. The liner lock has its merits but side by side I'd take a good frame lock or well made lockback over a liner lock any day of the week for your kind of uses.

STR

EDIT: to add loose pivot info.
 
Come back after using it and let us know how its worked or hasn't worked out for you.

STR
 
I saw a selection of the Tarani folders at a gun shop here and they do look pretty tough. I always thought the liner lock was suppose to be stronger until reading posts by you and a few others. I can't tell you how many knife writers extolled the virtues and strength abilities of the liner lock. I now understand why twisting a liner lock could be bad. Most of my knives are lock backs and frame locks now.
RKH
 
How would you classify an Axis lock in comparison to those mentioned. I now usually carry a 940 or 960. Stronger, superior, inferior, different all together? What have you seen? Also if you've had experience with ball locks how would they compare to backlocks in strength comparison?

It certainly is nice to be able to draw on someone such as STR's experience. Thx in advance

Shane
 
Yes. This is information is something that took a while to put together for many testers and evaluators and is still being argued about by many in the industry and among end line users that simply don't want to buy it Ron. However, the results are repeatable and easily seen if you know what to look for. On some static tests depending on the pitch angle of the contact the lock just slides right off the blade after a certain load is reached. Most of the ones I've tested that had 15 degree angles would do this so it indicated to me that they were only stable and trustworthy up to a point. Once that level was reached the lock had no choice but to follow the path of the ramp and slide off the contact.

I've made some with 12 degee pitch angles do this also and to be perfectly honest with you its happened enough to make me not even want to own any liners locks at all with a 12 or 15 degree angle to the contact. I focus on 10 degree or less and consider those to be the best for reliability reasons. They also prove to be quite strong for static load tests and you can see those in video clips and reports from testing all over from various places.

If the contact angle is done keeping in mind that the last thing you want to happen to the end line user is that the lock gives out from the pressure on the spine of the blade during use then it can be made to work in most all normal uses and even many extreme uses also. All the fuss over how to concave the contact, how to maniupulate the spring so it self corrects and anything else are examples in my mind of the efforts made by those that I feel didn't grasp what was going on with those twisting lateral stresses that everyone was missing in their consideration for what makes the lock the best it can be. Once those things are taken into account you then see people focused on the right areas to correct it.

I still see a lot of what I'd call 'over correction' in the industry trying to make the locks so they maximize the wear before they cross the tang completely while making them hit a sweet spot that is relatively flat that the lock will stick to. Some work and some don't. In the end I think it all boils down to a relationship with the mating and the pivot tension, as well as the degree of angle that the sweet spot is at where the lock tends to stay. Generally speaking the flatter that sweet spot is the more reliable the lock will be.

Historically speaking, when following the liner lock in it's evolution all this can be proven out. The LAWKS system is an invention that was created just to respond to these findings about lateral stresses and how these forces can play on what otherwise seemed to test out as a very strong lock for static loads or straight on forces testing the lock but as has already been covered numerous times here and in other forums that is not a real world example of the true nature of the forces the lock will experience in the hand during use.

You can tie a cable through the lanyard of your liner lock and put a winch on it and crank it out to tremendous stress all the while impressing yourself until you smile real big at how well you did making that lock. It means very little when you sell that knife to someone only to hear how it cut him or her during a cardboard box cut down and the reason for this is known now to be those lateral twisting torques that relate to the mating of the lock up in a big way during use. The hand being there to support the lock physically like with a good frame lock is the difference that takes the lock and blocks it from being affected by those stresses. Due to the nature of the lockback it is inherantly more reliable against these stresses and cannot slide off as the liner lock does. So in effect the lockback could be half the strength of the liner lock and stil be the better folder for reliabilty by a large margin.

STR
 
ss Dragonfly said:
How would you classify an Axis lock in comparison to those mentioned. I now usually carry a 940 or 960. Stronger, superior, inferior, different all together? What have you seen? Also if you've had experience with ball locks how would they compare to backlocks in strength comparison?

It certainly is nice to be able to draw on someone such as STR's experience. Thx in advance

Shane
Click to expand...

Shane there is no question that the Axis lock is superior in strength to the lockback and the liner and frame lock and probably as strong as the strongest ever made. So its covered all the bases quite well. The Axis lock is unaffected by the lateral stresses associated with liner lock defeats. When it connects as it should idealy it withstands sharp blows to the spine and spine whacking with impunity. About the only fault one can find with the axis lock other than the occasional complaint about the buttons sticking up too high is perhaps in the omega springs being so frail looking as to cause one to question their true life expectancy and durabilty, especially in severe frigid cold temps. However, with that said I guess so long as they are repairable and parts remain available (and it looks like that will not be an issue at this time) and the fact that there are two springs in the event that one does snap it is perhaps the best lock design for a folder ever concieved of by man.

One thing I've noted on more than one occasion is that in the event that both springs did break in a survival situation one could still make that lock work by jamming somthing up in there behind the bar to keep it in place. So in reality even if the lock gave out from no springs it would still be useable in a pinch.

The ball lock is great also. In many ways it equals the axis lock for strength and reliability and perhaps the new lock Spyderco will release with the button to move the ball back and forth will make it even more convenient to use. The one thing I do like about Sal's design over the axis lock is the coil spring. That spring will likely out live the omega springs by a wide margin. At least that is my guess.

For what its worth though I have seen more problems with ball locks than I have axis locks but both have defeated from spine taps when they were not working properly. So again it just goes to show you that in the end they are still man made and still folding knives which require some testing by the end line users to be sure they are up to snuff.

I like and own both types of these locks. I've found that many of the new locks are a step up from what we have grown used to. The Arc Lock by SOG is also quite strong and quite reliable. The compression lock by Spyderco is very reliable and strong but due to the nature of the forces being applied to it in the thinner lock versions it seems to suffer more from vertical blade play than the others mentioned. With that said though they are still a big step up in reliability and security from lock defeat problems compared to others like the liner lock.

Another little talked about lock that is highly reliable and very strong is the button lock. My only issue with the button lock is the position of the button on some models which in my hand made it far too easy to accidentally depress the lock in use which negates all that strength and reliability. I feel if this lock was developed like the old lever locks on some Bokers or if the button was recessed or could be locked so it can't depress that it would be one great lock and worthy of much higher praise. It is strong but there are different types of these locks and one must look to see just how deeply that pin goes down as well as how big it is in diameter to know exactly just how strong and more importantly, how reliable it would be in use.

As I've said lockbacks can be quite good. One thing about lockbacks that is not good is that you cannot visibly check to see just how much lock up you actually have. So a wide margin of trust is needed for most lockbacks which is why I personally like ones that come apart so I can see just what kind of contact my trusted carry knife has. I've seen many that seemed fine but sure scared me when I saw just how little lock was keeping my fingers from getting a cut so to me anytime you can see the lock up at a glance its a big plus. The Axis, ball, frame, compression and liner lock at least have this going for them.

STR
 
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