Locking area of your frame locks

[luh1202]

Hello guys, had this in mind for couple days now and I just want to share it and listen to what you guys think.
When we looking at a frame lock, I believe most of us looking at how deep it's locking, but IMO, it's not the full picture, I might be totally wrong.
I got two knives here to show. One hinderer xm18 gen6, one zt 0562.
Let's take a look at how "wide" it is locking.
#1 xm18
Only 20% of the width is contacting the blade.

#2 ZT 0562
Only about 40 % of the width is contacting the blade.

So both knives are not locking at their full potential. Every Chirs Reeve and Spyderco frame locks are contacting 100% that gave me "bank vault" locking feedback. If you handled a Sebenza, sage2 or tachno you know what I'm talking about. What do you think?

 

[Banter 247]

Chris Reeve Inkosis only actually have contact between the ceramic detent ball and the lock face, which is probably the least surface contact of any frame lock in the industry. Turns out, it’s not a big deal.

 

[luh1202]

Chris Reeve Inkosis only actually have contact between the ceramic detent ball and the lock face, which is probably the least surface contact of any frame lock in the industry. Turns out, it’s not a big deal.

Hard to disagree

 

[falar]

I only have one knife where 100% of the locking insert interfaces with the blade but it has a much thinner insert than any of my other knives. I think some people mean different things with terms like "20%" or "40%" too--are they referencing blade coverage or locking insert coverage?
Everyone has a different preference as well. I see some people that think 70 to 80 percent is too much, but clearly you are in the camp that prefers a lot and you're not alone. I see a lot of people that claim 30 to 40 is their sweet spot, while others would consider that "early".

As long as it is secure and there is room for wear, I'm good. I have knives that are anywhere from (when measuring % as it relates to the lock insert) 20% to 100% and they are all rock solid.

 

[luh1202]

I only have one knife where 100% of the locking insert interfaces with the blade but it has a much thinner insert than any of my other knives. I think some people mean different things with terms like "20%" or "40%" too--are they referencing blade coverage or locking insert coverage?
Everyone has a different preference as well. I see some people that think 70 to 80 percent is too much, but clearly you are in the camp that prefers a lot and you're not alone. I see a lot of people that claim 30 to 40 is their sweet spot, while others would consider that "early".

As long as it is secure and there is room for wear, I'm good. I have knives that are anywhere from (when measuring % as it relates to the lock insert) 20% to 100% and they are all rock solid.

It just confuses me that the steal lock bar insert is installed throughout the full width but only a fraction is being utilized... but I agree, it hardly influence the performance of the knife, at least for my use.

 

[Lapedog]

Hello guys, had this in mind for couple days now and I just want to share it and listen to what you guys think.
When we looking at a frame lock, I believe most of us looking at how deep it's locking, but IMO, it's not the full picture, I might be totally wrong.
I got two knives here to show. One hinderer xm18 gen6, one zt 0562.
Let's take a look at how "wide" it is locking.
#1 xm18
Only 20% of the width is contacting the blade.

#2 ZT 0562
Only about 40 % of the width is contacting the blade.

So both knives are not locking at their full potential. Every Chirs Reeve and Spyderco frame locks are contacting 100% that gave me "bank vault" locking feedback. If you handled a Sebenza, sage2 or tachno you know what I'm talking about. What do you think?View attachment 1091115 View attachment 1091116 View attachment 1091117 View attachment 1091118

A properly designed liner/framelock is supposed to only engage at the very forward right corner of the lockbar. (If you are looking down at the lock like in your second picture)

The reason for this is that between that point the stop pin and the pivot this is supposed to form a triangle of three points where the blade is contacting the frame. This is desirable because triangles are a very stable object. (Same reason a 3 legged stool will never wobble but a 4 legged one will)

If you take apart a sebenza (or any other well made liner/framelock) with 99% lockup and look at the lockbar lockface you will see only this leading corner of the lockbar is engaging.

 

[luh1202]

A properly designed liner/framelock is supposed to only engage at the very forward right corner of the lockbar. (If you are looking down at the lock like in your second picture)

The reason for this is that between that point the stop pin and the pivot this is supposed to form a triangle of three points where the blade is contacting the frame. This is desirable because triangles are a very stable object. (Same reason a 3 legged stool will never wobble but a 4 legged one will)

If you take apart a sebenza (or any other well made liner/framelock) with 99% lockup and look at the lockbar lockface you will see only this leading corner of the lockbar is engaging.

I see... unfortunately I don't have a sebenza by my hand at the moment but I'll definitely take a closer look when I get my hands on one. Thanks!

 

[Lapedog]

It just confuses me that the steal lock bar insert is installed throughout the full width but only a fraction is being utilized... but I agree, it hardly influence the performance of the knife, at least for my use.

Because it is easier to just replace the entire tip of the lockbar than to have just a tiny leading corner that contacts.

I only have one knife where 100% of the locking insert interfaces with the blade but it has a much thinner insert than any of my other knives. I think some people mean different things with terms like "20%" or "40%" too--are they referencing blade coverage or locking insert coverage?
Everyone has a different preference as well. I see some people that think 70 to 80 percent is too much, but clearly you are in the camp that prefers a lot and you're not alone. I see a lot of people that claim 30 to 40 is their sweet spot, while others would consider that "early".

As long as it is secure and there is room for wear, I'm good. I have knives that are anywhere from (when measuring % as it relates to the lock insert) 20% to 100% and they are all rock solid.

Lockup % usually refers to how much of the tang lockface is left for the lockbar to move across.

 

[007Airman]

I prefer about 33% interface of the lockface. There is really only one way to be sure which is strongest and that's actual testing so send me your fav folder and I will test them. Bear in mind that I will be hanging weights so keep your weak CRK at home, LOL

 

[sharp_edge]

Op your two knives lockup % are both fine. Although I would not say sth is wrong, I will avoid 100% lockup if possible.

 

[Alberta Ed]

If it holds the blade open with reasonable effectiveness it's OK.

 

[SteelJunkee]

It's going to wear and engage further with time no worries there. If a liner or a frame lock engage too far that can cause big problems.

 

[CdnMitch]

A properly designed liner/framelock is supposed to only engage at the very forward right corner of the lockbar. (If you are looking down at the lock like in your second picture)

The reason for this is that between that point the stop pin and the pivot this is supposed to form a triangle of three points where the blade is contacting the frame. This is desirable because triangles are a very stable object. (Same reason a 3 legged stool will never wobble but a 4 legged one will)

If you take apart a sebenza (or any other well made liner/framelock) with 99% lockup and look at the lockbar lockface you will see only this leading corner of the lockbar is engaging.

I never knew this about a three legged stool...this was very interesting! So is your analysis and explanation of how the lockup works...Thanks!

 

[Justin Schmidt]

This is desirable because triangles are a very stable object

90s kids and 3 wheelers would disagree

It's really the makers preference just like any other component of the knife.
The CRK method of using the detent ball at lockup is ingenious. Especially if he uses ceramic detent balls.
From what I've read and researched most people prefer 30-40% .its enough to be stable yet still allow for wear. Just my .02

 

[Lapedog]

I never knew this about a three legged stool...this was very interesting! So is your analysis and explanation of how the lockup works...Thanks!

That’s actually Emerson’s paraphrasing of Michael Walker’s description of how his improved Linerlock design was meant to work. So really I can’t take credit and you got a crazy broken telephone version.

The Michael Walker pattern of linerlock has become the standard for the industry for linerlocks and framelocks.

 

[marrenmiller]

As already noted by other posters, the lock face isn't supposed to lock up along its entire area.

The "bank vault" feel is likely due to a combination of placebo and lock geometry. Liner/frame locks can flex when they engage the tang too high up along the blade relative to the pivot. If you draw a line from the center of the pivot to the point of lock engagement, then another line at that point and perpendicular to the first line, you'll see the direction that the blade presses the lock when you attempt to force the blade closed. If the direction of that vector isn't pointing along the lock bar but rather upwards, the lockbar may flex until it is stopped by something else (like the rest of the frame).

I say placebo might have something to do with this because I noticed it on an umnumzaan that was otherwise in perfect working order, as well as on a bunch of Hinderers and other expensive knives, but I'll bet that nobody else wants to or is willing to notice that on theirs. Can't fix geometry, no matter how expensive your knife is.

 

[Sergeua]

For me I think there is a problem when the lockup is like this one

There is a ramp for liner or framelock to slide off when the the lock is on the very end of the lock face.
I want my locks, when they get to the edge, to be almost perpendicular at the end like this picture.
http://s173.photobucket.com/user/So-Lo-Kustoms/media/mili-lockup.jpg.html
Put the lock bar the very edge, move your digits away and apply pressure. It shouldn't be closing.

 

[Justin Schmidt]

As already noted by other posters, the lock face isn't supposed to lock up along its entire area.

The "bank vault" feel is likely due to a combination of placebo and lock geometry. Liner/frame locks can flex when they engage the tang too high up along the blade relative to the pivot. If you draw a line from the center of the pivot to the point of lock engagement, then another line at that point and perpendicular to the first line, you'll see the direction that the blade presses the lock when you attempt to force the blade closed. If the direction of that vector isn't pointing along the lock bar but rather upwards, the lockbar may flex until it is stopped by something else (like the rest of the frame).

I say placebo might have something to do with this because I noticed it on an umnumzaan that was otherwise in perfect working order, as well as on a bunch of Hinderers and other expensive knives, but I'll bet that nobody else wants to or is willing to notice that on theirs. Can't fix geometry, no matter how expensive your knife is.

The biggest thing with a tight lockup is the alignment of the lockface of the tang and stop pin. Any tiny bit of gap even if it .003 could make it feel loosey goosey. That was my biggest problem when I first started making folders was getting that PERFECT

 

[Comeuppance]

The ZT's lock interface is actually nearly 100%; the steel insert is the only part that is supposed to contact the tang of the knife, and that is something close to 90% under the blade tang in your picture. The Hinderer is a different story, but, man, I wouldn't worry about it unless you can force it to close.

Also maybe don't worry about it in general, since you're probably not cutting things with the back of your blade.

 

[marrenmiller]

The ZT's lock interface is actually nearly 100%; the steel insert is the only part that is supposed to contact the tang of the knife, and that is something close to 90% under the blade tang in your picture. The Hinderer is a different story, but, man, I wouldn't worry about it unless you can force it to close.

Also maybe don't worry about it in general, since you're probably not cutting things with the back of your blade.

Not a single ZT I've ever seen has had anything approaching 100% lock area engagement, and I've had a bunch of them. You can clearly see the space between the insert and the tang in OP's picture.