frame lock cut outs

Your right the pinnacle did not have a cut out. They also had problems with the lockup, at least the early versions did. Here is a quote I found regarding the knife

cutter17 said:
I went through about 4 of these back in the day. I had some lock issues with all 4 of them. Lock slipping, not going over far enough and allowing vertical blade play were the main problem.
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Lockbar cut outs help with reliability in getting the spring where it should be as well as easier manufacturing. It does not weaken a frame lock enough to matter. If you are using it in a manner where the Ti will actually buckle, the knife will most likely fail at other spots before the lock. Also, use the right tool for the job, and use some common sense and your lock wont fail.
 
The framelock has thicker steel for 90% of the length so the framelock will take higher loads for the buckling failure mode.

Adding the notch cutout in the framelock increases the stress concentration, so the stress will be higher at the cutout. There is probably at least a 20 factor of safety on this failure mode. It can be reduced by using more of a radius in the cutout as shown in the last photo.

The framelock design gets more surface area for contact between the lockbar and the blade. Therefore the lockbar design (if heat treated to the same hardness) is better for the brinelling failure mode.

The framelock design also provides higher force on the detent mechanism which some people think is desirable.

My 2 cents.
 
zulutime said:
benchmade pinnacle is a framelock that has no cutout. its very easy to unlock.
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Not true. The Pinnacle's lockbar is hollowed out on the inside. There's a groove about an inch long on the far end. If you owned a BM Pinnacle, you'd know that.
 
I can't find the thread but someone started a thread on lock bar strength for the framelock vs the liner lock. Maybe some one can find it and post it to eliminate some of the misconception and un answered questions about frame lock, lock bar strengths. If I remember correctly the framelocks weren't all that tough. A frame lock holding +800lbs of pressure on the lockbar is just silly
 
With most modern framelocks of decent quality, you can drive the locked folder into a tree (with your hammer) at six feet high and do pullups...assuming you weight 200 pounds or less. The lock won't fail.
Please note that framelock and cutout design is widely varied.
1) Cutout thicknesses generally vary from about 0.040" to 0.060".
2) The radial widths of cutouts vary from approx. 0.4" to 0.8" wide. (along the length of the lockbar)
3) The transverse cutout width will vary from 0.4" wide all the way to 0.8" wide. (Some lockbars are very wide at the cutout position, like a Strider SMF)
4) The cutout shape varies widely; from a U-shaped to a squared-off channel, or in the case of CRK...a long squashed letter W.
5) The actual physical length of the lockbar itself will vary from as little as 1.8 inches long to over 3.1 inches long. (tremendous difference in structural stability)
Use your framelock in a manner that would likely be interpreted (by your doctor and lawyer) as reasonable use...and it will not fail you. Save the batoning for your longer fixed blade in CPM 3V bladesteel, and you will go home from your hike...both happy and healthy.
Sonnydaze
 
I find it interesting that there is so much emphasis on the thickness of the Titanium, when actually, the failure of a lock will most likely happen at the lock interface with the blade.
 
marthinus said:
I find it interesting that there is so much emphasis on the thickness of the Titanium, when actually, the failure of a lock will most likely happen at the lock interface with the blade.
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exactly. that, and the cut out acts like the crumple zone on a car, if it ever reaches that point of failure it will fail in the safest way possible.

like people who think old cars from the sixties are safer than new "plastic" cars because they're all steel. I saw an old gto and a newer Camry get into an accident, and the gto's passenger compartment was a disaster, whereas the Camry was fine minus some crumpled body panels.
 
goodeyesniper said:
like people who think old cars from the sixties are safer than new "plastic" cars because they're all steel. I saw an old gto and a newer Camry get into an accident, and the gto's passenger compartment was a disaster, whereas the Camry was fine minus some crumpled body panels.
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That may be true but I've heard older body-on-frame Jeep Cherokees are real beasts when it comes to crashing... at least, for the Cherokees themselves, not for the occupants who don't get the pillowy effect of a crumple zone. :D
 
There have been frame and liner locks tested to failure that didn't make it past 60 lbs, so it depends on the knife (and these were $100+ knives). STR made several of the He man folders, it wasn't just a one off custom http://strsbackyardknifeworks.blogspot.com/2009/06/medium-ril-reeve-integral-locking.html Also John Greco made/makes the steel frame lock Whisper and Falcon, I had a couple of those and they don't have relief cuts. I am not the biggest fan of the frame lock, and the compromise of lost material in the single point of failure for both the spring and lock bar to allow for comfortable use is one reason. The use of a frame lock adds weight to the handle, while the need for a cutout reduces strength.
 
I think it is a betting game that the lockbar won't slide out back to where it came from vs the crumpling/buckling mentioned above. If the face is designed to prevent sliding back out it also has to be treated a certain way or be proper steel so the face geometry doesn't change from wear and/or excess pressure. Straight up titanium wanting to mold itself to mate with the blade tang's curve.
 
Let me get this clear, cutouts on a titanium frame lock are a bad thing if you intend to smack the back (spine) of the blade with a significant amount of force or impact loading.

If that's your thing then stay away from Ti frame locks.

I imagine having no cutouts won't help much under such conditions and few folding knives will stand up to such conditions.

Why?

Because knives usually have a cutting edge and that edge is designed to be pushed, sometimes with a sawing motion into whatever sensible material is being cut.

With a frame lock his generates forces on the blade which apply no force at all on the lock bar (or an insignificant amount of force) so, under normal usage the cut outs in a frame lock will never be exposed to enough compressive loading to cause a failure.

The cut out may be a stress riser but again only of concern when applying heavy abnormal compressive loading which the system was not designed for.

It's like criticising suspension bridge cabling for having poor compressive properties.
 
I've never seen a well designed one fail at the cutout.
The man that invented the RIL knew what he was doing, and I thank him for giving it to us.
Its by far my favorite lock.

When I baton its done with a fixed blade.
 
Dorito Monk said:
Like this one?

Emerson+HD7.jpg
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Note the cut out is on the inside, it is stronger to do the cut out on the out side, as the force isn't so direct that it bends it
 
Jaytaylor said:
Let me get this clear, cutouts on a titanium frame lock are a bad thing if you intend to smack the back (spine) of the blade with a significant amount of force or impact loading.

If that's your thing then stay away from Ti frame locks.

I imagine having no cutouts won't help much under such conditions and few folding knives will stand up to such conditions.

Why?

Because knives usually have a cutting edge and that edge is designed to be pushed, sometimes with a sawing motion into whatever sensible material is being cut.

With a frame lock his generates forces on the blade which apply no force at all on the lock bar (or an insignificant amount of force) so, under normal usage the cut outs in a frame lock will never be exposed to enough compressive loading to cause a failure.

The cut out may be a stress riser but again only of concern when applying heavy abnormal compressive loading which the system was not designed for.

It's like criticising suspension bridge cabling for having poor compressive properties.
Click to expand...

But then there is the issue of folding 'fighting' 'combat' or 'survival' knives, where spine thickness, pivot size, alloy toughness, etc are advertising points. If all you are going to do is cut with the edge in controlled conditions, then a friction folder or slipjoint also stands zero chance of failure and that design philosophy or ad copy is totally meaningless.

People might have a practical reason for choosing frame locks, but I'm honestly not too sure what it is. A subjective admiration for the lack of parts or stark appearance maybe, but it isn't for strength - even though there are literally hundreds of posts where it is stated and advised that getting a 'beefy' frame lock will approximate a fixed blade or at the very least provide the user with the absolute strongest folder possible. This just ain't true.

If used the right way, you can't tell the difference between locks, or between knives with and without locks, so where is the distinction made between different locks and not between knife brands or models?

But I'm going to bow out of this thread, because I realize once again I cannot find a positive thing to say about these locks and I don't want to create friction. (that could have been a pun if I was more clever)
 
It is laughable to say the cut out reduces strength, whilst technically correct no amount of force under normal operating parameters will come close to the loading required to cause failure.

How many frame locks have failed due to the cut out?

A search of the web only comes up with the photo already posted in this thread.

If it really was a issue of concern this forum should be full of accounts, photos, disgruntled owners.

The reality is, if there are owners of reasonable quality frame locks which have failed due to a cut out I can not find them.
 
Agreed, just seems the added weight and beefiness is all for nothing because of these thin cutouts. Why not just go with a lighter, just as strong liner lock with scales on both sides, and your grip doesn't get in the way when opening. I do like that you have more control of the lockup with frame locks but for the amount of weight, I will just stick with a lighter fixed blade and problem solved.
 
richardallen said:
Not true. The Pinnacle's lockbar is hollowed out on the inside. There's a groove about an inch long on the far end. If you owned a BM Pinnacle, you'd know that.
Click to expand...

not true, i have two benchmade pinnacles. If your head wasn't hollowed out on the inside, you'd know that.
 
People keep writing me telling me about this thread giving me links asking me to please come in and add input and I'm like oh man not again. Guys I really don't want to talk about it anymore. I've talked about it. Its a non issue really at least in the real world. If you just want my thoughts on this to see where I stand its out there and you can pretty much find my thoughts here on my blogger link below. That post got corrupted and is actually much older than the current date as my blog went haywire for a time but I think I pretty much agree with what I put here. I haven't read it in a while but you know my opinion on lock cuts is that if someone wants it to look thicker just to feel better about it why not taper the cut some making it deeper where it is hidden and thicken out some as it reaches the bottom of the folder lock area. Some like to think the knife is 'bad ass' and just like many other things that indicate such from camo stripes, to bull pivots, to skull logos and more add to that macho appeal to satisfy the ego of the pocket jewelery enthusiast. Don't get me wrong I mean I realize some of you guys actually use your knives but the pictures always look so pretty and all hardly a scratch. I just don't know how you do it! :D

Seriously, we don't hear about this issue enough to warrant further discussion on worry over it but since three readers have written me asking for comment from me in the last few days just see my blog in the June 2012 post. Its actually a much older post from years back though probably five or more years if not six as I copied and pasted to make parts of it from various posts made here scattered throughout the forum. So if you think it looks familiar that is why.
 
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