Industry not listening?

[MikeC]

Over the years I read too many post to count concerning frame locks and more specifically about titanium frame locks and the thickness or really thinness of the relief cut. I have also noticed several post of reputable people on this site posting pictures of failed titanium frame locks where the relief cut has suffered a catastrophic failure for whatever reason and collapsed.

Recently there has been a post here about an inexpensive (not cheap) folding knife with composite scales (no metal in frame/handle) with what by most here is considered lower end steel that is tough as nails. There are also comments from engineers in that thread about frame locks and failure and most specially about titanium frame lock failure. Moreover nearly all of the post about relief cuts inevitably leads to the question why are they so thin.

Titanium frame locks are without question a big hit in the knife market, with so many people raising valid points about relief cut thickness or lack thereof, by and large why isn't the industry listening?

Take for example the Acies, I went to buy one and then saw a youtube review and noticed the thinness of the relief cut and passed. Titanium is a notch sensitive material basically meaning that if you notch it, say like for a relief cut the cut needs to be shallow and long, the shallow and longer the better titanium likes it. With the converse being true as well, cuts that are deep and short is not what the titanium responds best to in fact from the way it has been explained to me that is the worst way to do it.

So why isn't the industry listening. I love titanium frame locks and have only ran across 3 that have a fairly robust relief cut meaning shallow and or shallow and long.

I understand that many of these ti frame locks are safe and or pocket queens carried man jewelry but what about those of out here that actually carry them and use them as the tools they are.

 

[Grimspoon]

If I'm understanding correctly doesn't Rick Hinderer address this issue through the use of the lock bar stabilizer?

 

[SPXTrader]

This could be interesting. Would you care to link some of the threads and/or pics regarding the failures? And possibly a link to the thread about the particular knife you're talking about?

I read a lot here, and have missed most of what you're talking about. I do know that recently the relief cut has been discussed. I have beat on a lot of Ti frame locks and never had a failure.

 

[Dnullify]

I'm sure plenty do use them as the tools they are.

If i understand correctly, you're saying that Titanium's plasticity is higher when the relief cut is short and deep. I guess i agree, that makes sense that the bar would be brittle. However, many makers who utilize these designs are likely to have thought this design through, as it seems to be the first weak point of the design at first glance.

I think, at a certain point, if the lock-bar is going to break, it's going to break. short of not having any relief at all, there's always that point of over-extension, or material fatigue that is inevitable.
I've seen pictures of people's sebenzas that are 10 years old, whose locks look perfectly robust.
There is also the Hinderer frame-lock stop, which stops over extension, and as a result lessens fatigue.

 

[clockman]

If I'm understanding correctly doesn't Rick Hinderer address this issue through the use of the lock bar stabilizer?

+1:thumbup:

All my frame locks are high/higher end and dont have the problems youre
addressing.

 

[slimshaneee]

The way I understand it, if the titanium is too thick, it is too hard to unlock. And would put too much pressure on the blade while opening and closing if it were to lock properly.

In other words. If the lockbar is thicker the lock is much stiffer.

Also, I would love to see a framelock that was destroyed by anything other than RIDICULOUS abuse.

At some point you have got to trust that with all of the knifemaking minds involved in making titanium framelocks, they are making them about the best they can.
It is likely that you don't understand why they do it. If they aren't listening it is likely because what is being said does not make sense.

 

[RevDevil]

Perosnally, I want to see some data on stress tests performed on the Ti frame locks out there. The fact is that unless I had no other alternative, I wouldn't be using a folding knife as an axe, machete, prybar, sword, throwing knife, shovel, rake, etc.

However, tests to determine frame lock failure points would be interesting. I guess they are not readily available for a reason.

 

[twid]

So why isn't the industry listening.

Because they haven't watched nutnshmancy's videos.

 

[Obsessed with Edges]

I think you'll find that most of the 'quality' manufacturers of Ti framelocks generally consider that the kind of stress needed to make a lock fail usually comes about as a result of ABUSE. In other words, the maker feels no need to compensate for users who try to use the 'tool' for something it was never designed to do (like batoning with a folder, or stabbing a refrigerator or car door, or using a folder as a prybar).

 

[barrabas74]

I think you'll find that most of the 'quality' manufacturers of Ti framelocks generally consider that the kind of stress needed to make a lock fail usually comes about as a result of ABUSE. In other words, the maker feels no need to compensate for users who try to use the 'tool' for something it was never designed to do (like batoning with a folder, or stabbing a refrigerator or car door, or using a folder as a prybar).

You are probably right, however if you KNOW that something could be better using the same thickness materials yet making a simple design change....why wouldnt you? If you can keep all things the same except the relief cutout depth and width why not do so and make things stronger?

I am not asking you these are just questions I would have for knife manufacturers and makers who use framelocks.

 

[Obsessed with Edges]

You are probably right, however if you KNOW that something could be better using the same thickness materials yet making a simple design change....why wouldnt you? If you can keep all things the same except the relief cutout depth and width why not do so and make things stronger?

I am not asking you these are just questions I would have for knife manufacturers and makers who use framelocks.

I thing manufacturers have to walk a pretty thin line with regard to the lockbar on framelocks. On the one hand, everybody wants it to be as strong as possible. On the other hand, for some people, a very STRONG lockbar usually means a very STIFF (difficult to disengage) lockbar. People won't buy a framelock that has a reputation for chewing up thumbs and, at the same time, they won't trust one that has a reputation for being flimsy. Over time, I'm sure the better makers do make some subtle 'tweaks' to optimize strength and ergonomics. But, everybody's idea of what's 'better' is subjective to the end user (and the maker).

 

[OrangeJoe]

I believe most people want 'flickability'. A lack of cutout
does away with the weak feeling (to me) ball detent, but may make opening the knife a two handed affair.

 

[Obsessed with Edges]

I believe most people want 'flickability'. A lack of cutout
does away with the weak feeling (to me) ball detent, but may make opening the knife a two handed affair.

I think the 'cutout' (relief cut) referenced in this discussion is not the thumb cutout in the side of the handle scale, but the 'notch' (relief cut) on the inside of the lockbar, which allows the lockbar to flex inward (to lock the blade). Doesn't have anything to do with opening.

 

[hardheart]

Yes, it does. He's saying that if you remove the cutout, the pressure applied to the blade in the closed position makes it too stiff to flick open. I had a Greco that was a monster. Opening was not as hard as closing, but both definitely harder than average.

 

[OrangeJoe]

I think the 'cutout' (relief cut) referenced in this discussion is not the thumb cutout in the side of the handle scale, but the 'notch' (relief cut) on the inside of the lockbar, which allows the lockbar to flex inward (to lock the blade). Doesn't have anything to do with opening.

in designs l that lack the cut, the knife may be
held closed by the lockbar
pressure alone. There is no ball detent, therefore the knife does not flick open.

 

[UpChUcK]

I believe most people want 'flickability'. A lack of cutout
does away with the weak feeling (to me) ball detent, but may make opening the knife a two handed affair.

I think the 'cutout' (relief cut) referenced in this discussion is not the thumb cutout in the side of the handle scale, but the 'notch' (relief cut) on the inside of the lockbar, which allows the lockbar to flex inward (to lock the blade). Doesn't have anything to do with opening.

I believe OJ is referring to the relief cut and he is stating that if the lockbar tension is too strong, opening as well as closing the blade will be more difficult due to the increased pressure the lockbar may place on the tang of the blade.

 

[OrangeJoe]

Exactly what HardheArt and UpChUck have posted!

I believe STR offers the option of no lockbar cutout on his custom made knives, he calls it the 'He Man' option.

Sorry about the goofy formating; my laptop has been acting up.

 

[Obsessed with Edges]

Yes, it does. He's saying that if you remove the cutout, the pressure applied to the blade in the closed position makes it too stiff to flick open. I had a Greco that was a monster. Opening was not as hard as closing, but both definitely harder than average.

That's interesting. I wasn't aware that any framelocks existed with no cutout at all in the lockbar.

On the other hand, I'd think ease of opening could be optimized through other means, like a more refined/smoother detent ball, detent ball backed by a coil spring, thumb lug/disc designed for better leverage, etc. I'd think even the radius of the detent ball could be optimized for smoother operation.

 

[FlaMtnBkr]

As has been mentioned, trying to bend (unlock) a thick piece of metal is going to be hard. There is going to be a certain range of thickness that can be flexed easy enough to bend with your thumb. If most locks are a certain thickness then it is because that is the thickness that allows the knife to be unlocked easy enough and not tear your thumb up.

Certain things can be done though to make it stronger. Multiple cutouts can be used so that the bar flexes at one spot so far and at the next spot so far again. The lock bar can be looked at as a spring which the further you move it, the harder it is to move.

The placement of the cutout also matters whether it is on the outside or the inside. Since the lock normally engages the blade tang on the inside edge it is best to have the cutout on the outside. This way the force of the blade closing travels in a direct line down the inside edge of the lock bar. If there is a cutout the force has to travel around the cutout and puts outward force before the cutout as it changes direction to route around the cutout. The cutout on the outside might not look as good but it is stronger.

A frame lock that has a cutout section that is thinner is going to be stronger than a liner lock that is the same thickness as the cut out. In a liner lock since it is long and narrow there can be a buckling mode of failure that is not in the frame lock. Since it is skinny and long it can buckle and bow out in the center at a certain force. It is similar to taking a thin branch and pushing down on one end and it suddenly bowing out in the center. A thick branch wont do that.

I am not a big fan of frame locks personally. They can be strong and last a long time, but some behave differently. Some will move with spine pressure on the blade and start to walk across the tang towards the unlocked position. There isn't really any way of knowing which will do this and which will be fine. They can also start doing this at some point after they have been used for a while and wear to a certain point. Also, the lock bar can wear and move across the blade tang towards the other scale fairly quickly on some knives. Again, it is hard to tell which will behave this way. And once it wears and moves all the way over blade play develops and there is no way to fix it. The lock bar has to be replaced or the knife trashed. Other lock types I can fix at home if I don't want to send the knife off but not with a frame/ liner lock. I have had a few knives unlock with light spine pressure. I have also had a frame lock wear out in less than a year with very light use. This is not something that I like or want to pay for when there are much better designs available. Again, that is my opinion. I have had some that are strong and don't seem to wear out, but I have no idea what I am getting when I buy it so I try my hardest not to buy them.

 

[mmarkh]

Over the years I read too many post to count concerning frame locks and more specifically about titanium frame locks and the thickness or really thinness of the relief cut. I have also noticed several post of reputable people on this site posting pictures of failed titanium frame locks where the relief cut has suffered a catastrophic failure for whatever reason and collapsed.

Recently there has been a post here about an inexpensive (not cheap) folding knife with composite scales (no metal in frame/handle) with what by most here is considered lower end steel that is tough as nails. There are also comments from engineers in that thread about frame locks and failure and most specially about titanium frame lock failure. Moreover nearly all of the post about relief cuts inevitably leads to the question why are they so thin.

Titanium frame locks are without question a big hit in the knife market, with so many people raising valid points about relief cut thickness or lack thereof, by and large why isn't the industry listening?

Take for example the Acies, I went to buy one and then saw a youtube review and noticed the thinness of the relief cut and passed. Titanium is a notch sensitive material basically meaning that if you notch it, say like for a relief cut the cut needs to be shallow and long, the shallow and longer the better titanium likes it. With the converse being true as well, cuts that are deep and short is not what the titanium responds best to in fact from the way it has been explained to me that is the worst way to do it.

So why isn't the industry listening. I love titanium frame locks and have only ran across 3 that have a fairly robust relief cut meaning shallow and or shallow and long.

I understand that many of these ti frame locks are safe and or pocket queens carried man jewelry but what about those of out here that actually carry them and use them as the tools they are.

If the knife is used correctly you won't bend a framelock. It is a knife, not a tent peg or tree climbing step or a crowbar.