Ti Frame Locks; Lock Bar Relief Cutout?

[Lenny]

I just don't get it.
Unless it's an integral handle, isn't it just as easy for the maker to mill the lock bar relief cutout
on the inside of the lock bar as on the outside? Clearly it makes for a cleaner
looking knife. But why do so many makers, including high end ones, mill out the
relief cutout on the outside? What am I missing here?

 

[Riz!]

It may be stronger to have the forces pushed straight through the lock bar. Meaning when the cut is on the inside, the forces travel down the inside of the bar then jump over to the outside of the bar. When the cut is on the outside the forces travel straight through. Im not an engineer but I stayed at a holiday inn once!

But… Chris Reeve puts the cut on the inside so that might throw my hypothesis right out the window

Maybe its just easier not to have to flip over the scale when milling it out.

 

[Lenny]

OK, good points.
I'm a CRK fan and even own a Sebenza now.
However, the Sebenza is one of the few Ti frame lock knives that
shows flex in the lock bar when pushing down on the blade.

 

[Riz!]

Maybe my hypothesis is valid.

 

[Mimic Knife & Tool]

I just don't get it.
Unless it's an integral handle, isn't it just as easy for the maker to mill the lock bar relief cutout
on the inside of the lock bar as on the outside? Clearly it makes for a cleaner
looking knife. But why do so many makers, including high end ones, mill out the
relief cutout on the outside? What am I missing here?

I’m with you, I always wondered the same thing! Also having the relief on the inside avoids a snagging point when drawing the knife from your pocket.

 

[Kettleman]

OK, good points.
I'm a CRK fan and even own a Sebenza now.
However, the Sebenza is one of the few Ti frame lock knives that
shows flex in the lock bar when pushing down on the blade.

I have a Sebenza 25, relief cuts inside, in my pocket right now. It has no lock flex. May I ask why you would push down on the blade? What pray tell are you trying to simulate buy using the tool backwards?

 

[sharp_edge]

I have a Sebenza 25, relief cuts inside, in my pocket right now. It has no lock flex. May I ask why you would push down on the blade? What pray tell are you trying to simulate buy using the tool backwards?

You seem to have been a CRK fan for a while so you shall know that the lockbar flex being mentioned here is when one pushes the edge (not the spine) hard into something the lockbar may flex. There is at least one long thread on the CRK subforum discussing this topic when Sebenza 31 was still relatively new.

 

[Kettleman]

You seem to have been a CRK fan for a while so you shall know that the lockbar flex being mentioned here is when one pushes the edge (not the spine) hard into something the lockbar may flex. There is at least one long thread on the CRK subforum discussing this topic when Sebenza 31 was still relatively new.

When one pushes the edge into something hard the lock bar doesn't flex it travels a bit on the 31. When pushing with the edge there is no pressure on the lock bar. As for the flex everyone was in a tizzy over on the 31, which by the way was corrected in the later part of 2021, I ask again why are you using a tool backwards?

 

[Lenny]

I have a Sebenza 25, relief cuts inside, in my pocket right now. It has no lock flex. May I ask why you would push down on the blade? What pray tell are you trying to simulate buy using the tool backwards?

This was a major discussion in the CRK forums after the Sebenza 31 came out. In theory, I agree with you.
But almost no other Ti frame lock knife exhibits this behavior.
Glad to say my Small 31 doesn't exhibit it either.

 

[Lenny]

You seem to have been a CRK fan for a while so you shall know that the lockbar flex being mentioned here is when one pushes the edge (not the spine) hard into something the lockbar may flex. There is at least one long thread on the CRK subforum discussing this topic when Sebenza 31 was still relatively new.

Um, first I've heard that.
All descriptions, and You Tube videos show it flexing from spine pressure.

 

[Tsujigiri]

Outside cutouts mean that the supporting material is more inline with the blade, so the lock is less likely to buckle. For Chris Reeve, absolute strength isn't the top priority for their knives so much as usability.

I'm not sure exactly how they fixture and machine the handles on these knives, but depending on the design, putting the cutout on the inside might mean having to refixture the piece, adding machining time and cost.

 

[J. Doyle]

I think inside vs. outside is far more ease of manufacture/maker preference than anything.

But I know makers who will argue one way is better/stronger than the other. And I've heard those arguments for both ways. I think they just want to justify their own way.

 

[Danke42]

Not every maker is enamoured of clean looks. Some want to show of what the fancy new numerical control machine can do.

 

[tony281sc2]

Not every maker is enamoured of clean looks. Some want to show of what the fancy new numerical control machine can do.

Was just thinking I kind of like the machining lines on the cutout, like on a Hinderer. It goes well with the industrial look of the knife

 

[Danke42]

I would say one feature of having it to the outside is less of a cavity inside the handle to accumulate lint and grime next to the blade.

 

[tony281sc2]

Then you have some cut outs, like the Shiro Quantum, that not only look good, but give you some extra room under the pocket clip to get it over thick pants.

This clip would be ridiculously tight if it didn’t have a LB cutout

 

[TimButterfield]

My personal preference is the way CRK does it. Here is a capture of my large Sebenza. It has the main cutout on the inside, which gives a cleaner look. But, it has subtle grooves on the outside also.

 

[353]

You seem to have been a CRK fan for a while so you shall know that the lockbar flex being mentioned here is when one pushes the edge (not the spine) hard into something the lockbar may flex. There is at least one long thread on the CRK subforum discussing this topic when Sebenza 31 was still relatively new.

When u do this the the blade is pushed into the stop pin, there cant be no lock bar flex doing this.

The thread u mention is when force is put on the spine.

 

[Honed_Edge]

My personal preference is the way CRK does it. Here is a capture of my large Sebenza. It has the main cutout on the inside, which gives a cleaner look. But, it has subtle grooves on the outside also.

Only the inlaid CRK have the external two lines. Look at the wood versions. That's where the blast vs polish portions meet. It's only for cosmetic reasons. The micarta inlaid ones still have the lines, all blasted though.

I though you were going to talk about the two partial conjoined cutouts inside. That is rather unique. Most knives have a cutout that is uniform in thickness. I'm not sure the physics but I feel this distributes stress better.

 

[TimButterfield]

Only the inlaid CRK have the external two lines. Look at the wood versions. That's where the blast vs polish portions meet. It's only for cosmetic reasons. The micarta inlaid ones still have the lines, all blasted though.

I though you were going to talk about the two partial conjoined cutouts inside. That is rather unique. Most knives have a cutout that is uniform in thickness. I'm not sure the physics but I feel this distributes stress better.

The only wood CRK I have is a box elder burl small Sebenza, but that is also an inlay. Maybe that is why it also has the two external lines. The double cutouts are similar on some of the other Ti frame locks I have. But, while those others have a wide cutout, they just don't have the raised line between the two sides that is created by the double rounded cutout on the CRK. For example, my Spyderco SpydieChef has a flat wide cutout while my Spyderco McBee has a textured cutout. The cutout of both is wide enough to be flat across the bottom and not just a rounded cutout. Here are images of those three.