Folders Vs. Fixed Blades; A question of strength

[Snickersnee]

Conventional wisdom holds that a folder can never be made as strong as a fixed blade.

In order to answer this question, we really have to figure out what we're talking about;

I'd reckon that a stick tang fixed blade knife of same size as a folder wouldn't necessarily be any stronger than that folder, depending on style of lock.

So since that's an easy situation to find parity, let's think about the hardest scenario without getting too exotic, a "sandwich tang" or what is also called a "full tang" in which the tang extends both the full length and width of the handle, and in "sandwiched" between the two scales. Like on the Western W-49.

Anyway, assuming similar sized knives, is there really a reason why the folder can't be as strong?

We've all seen knives broken in vices, and the vice, in a sense, could be seen as a lock. So, I believe it is actualy possible to make a lock that is as strong as a fixed blade, the main thing is, how would it work in a knife that'd still be practical?

Going with the vise idea, I see a tempered handle, machined from a solid ingot of good steel, with a vice-like screw opperated lock, and massive rivets holding it together.

Without actualy engineering the thing, I can't speak for weight or usability, but something like this seems like it could be as strong as a fixed blade, at least in the 4 inch long blade class.

I'm sure there are many other contenders, probably quite a few that would be much more practical. Any thoughts on the subject?

 

[Cliff Stamp]

Folders can be strong, strong enough so that direct up/down pressure large enough to defeat them is not easily done by hand. For example the Rolling lock takes over 400 lbs of force on the handle to overcome the lock. However how much force can it take it a sideways motion? What is its "strength" if the lock gets debris in the mechanism?

In terms of pure strength, the best I have seen is on the Uluchet which can take strain in both the left/right and up/down planes that will break a fair number of fixed blades.

-Cliff

 

[longbow]

I can't belive this thread is posted. Just last night as I was digging a judo point arrow out of a stump with my Kershaw 1416 I was wishing I had my fixed blade Trail Guide with me. The question of lock strength etc. definetly entered my mind as I was twisting, chopping and hacking the darn thing out. My conclusion is this, there is no folding knife what so ever that is as strong as any type of fixed blade, stick tang as my TG is, full tang, tapered tang, etc etc. I now have a slight side to side movement in the blade that won't adjust out and also a slight back and forth movement. This isn't to say that the locking type mechanisms won't work and work well. For there intended purpose they work fine. I just don't think for the kind of work it was doing last night to remove the arrow they are cut out for it, so to speak. Keep'em sharp

 

[Willie Boy]

A couple of days ago, I picked up the flagship issue of new annual magazine called TEK-KNIVES. TEK-KNIVES is put out by Blade magazine. On page 34 of said magazine is an article called Future Lock by Steve Shackleford.

The article contains interviews of Jason Williams and Bill McHenry, co-designers of Benchmade's Axis Lock. Jason Williams said of the Axis Lock, "The Axis LOck is as strong as the materials you make it out of, which means it is as strong as any straight knife because (in stress testing) you have to break the blade before you can break the lock."

Also interviewed was Bob Brothers, who along with Bob Taylor, designed R.E.K.A.T.S rolling lock. The artile discusses the tremendous strength of the rolling lock but stops short of stating it is as strong as a fixed blade. They do say, however, that for the lock to break, the steel itself must shear.

 

[goshawk]

I've been working on several designs for hunting folders that would stand up to all
kinds of pressures. The present locks will
hold up under alot of pressure and most of
them depend upon the blade breaking before
the lock. My reasoning is not that the steel
in the pins ( ie axis ) but how fradgil are
the screws attaching these pins or the pivot
or what ever. I've replaced some of these
with grade 8 and some have still failed. Yes
I own some production folders woooha I am
impressed with bm axis but have modified it.
Even so I would prefer one of my wimpy?

stick tangs if I was in a bind..
I've been working on a folder that has a slotted pivot pin and the back of the blade
is similar to a stub tang that slides back
into the handle and is sandwiched up and down
side to side in solid steel. It isn't designed for speed or one handed operation
but compactness and TOUGH.

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http://www.imt.net/~goshawk
Don't walk in tradition just because it feels good!!!!!
Romans 10:9,10
Psalm 91




[This message has been edited by goshawk (edited 19 August 1999).]

 

[SB]

Is a convertible less than the hard-top? While we debate this thread, let's not forget that it ultimately comes down to the driver.

 

[Marion David Poff]

Let's look at this form another standpoint.

Weight for weight.

Given a folder and fixed blade of equal weight and common distrubution of that weight, the fixed blade will be stronger.

I trust none of these lock claims, unless they are bore out by my experience, because I trust no company to tell me if their knives are safe or not, they have a bottom line to look out for, money.

That is why I trust Spyderco and Reeve, they honestly say that you can break their knives, they just don't believe you can do it easily.

------------------
Marion David Poff aka Eye, one can msg me at mdpoff@hotmail.com If I fail to check back with this thread and you want some info, email me.

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http://www.geocities.com/Yosemite/Meadows/1770/index.html

 

[Marion David Poff]

Is this hypothetical or realistic?

Where are you taking this?

As far as I am concerned the folders out there offer plenty of strength. And the main reason I carry them is convenience.

If I want anything else I head for a fixed.

I ask not to be agumentative, but to get an idea of the context of your question.

MDP

 

[Mercury]

Axis-Lock: Strong, smooth, backed by twice the effective spring power it needs, and works when dirty. Just look at the thing... It may not be a solid piece of metal, but that mechanism is WIDE OPEN. Cycle it a few times, look at it... It will work when dirty, it will work fine.

I do not like the entire Rolling Lock thing, I have tried one and I found it to be very uncomfortable and quite closed off to possible cleaning if needed. Forget keeping the dirt out, it keeps YOU out. I don't know what is in that lock, I don't like that one bit. With the Axis-Lock you can pretty much see the whole deal out in the open. Knives like the Axis-Lock and the Gerber Applegate series really feel like fixed blades when they are open, do they not? That feeling comes from nothing less then a general level strength.

For me, it isn't a question of strength at all atually. Well, not as much as it might be for you guys. I know a fixed blade will take more of everything then a folder, more twisting and more flex and weight here and here, in this little corner, right over there and on that little thing over here. And, when out in nature or something, I am going to tote along a SOG fixed bade, nothing less. Why take a folder into a situation where you can readily keep a fixed blade displayed and ready to go? I carry a folder everyday because, among other reasons, I feel too out in the open with anything else.

I have had so many people tell me that having a knife won't do me any god in a tense situation, that gun is "The real stopping power a person needs to defend himself". Huff. Well, I am NOT going to take out a gun for a situation that may or may not turn out to call for its use. It's a gun... let's be honest here. But, I will take out my knife, sub four inch blade, whenever I feel the need to, and that includes self defense. I will give up strength for availability onto myself. No gun for self defense, no fixed blade for opening up boxes and cutting loose yoyo string from all over the place. Not for me anyway.

------------------
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[This message has been edited by Mercury (edited 20 August 1999).]

 

[WrongFriend]

I'm not familiar with latest locking system, but I think I can point out one thing.

If here's a very nice folder of any kind with a strongest lock, still I can weld or glue the lock and make a strongER fixed knife of it at some degree...

Or did this "strength" talk come from another standpoint? Sorry if I misread you guys.

------------------
\(^o^)/ Mizutani Satoshi \(^o^)/

 

[Cliff Stamp]

Marion :

As far as I am concerned the folders out there offer plenty of strength. And the main reason I carry them is convenience.

Isn't that the only reason to carry a folder anyway? They are directly inferior to a fixed blade in every other respect. The whole "if you want something stronger carry a fixed blade" if kind of off, as if you can carry a fixed blade it does not make much sense to carry a folder.

There is one exception to this though. The Uluchet folds not to close the blade but to change the intended utility focus of the blade. When it is extended it is a small hatchet and works well on chopping. When folded it is a nice skinner. I would rather carry that than a fixed hatchet becuase it would not have the same abilties.

-Cliff

 

[hso]

All things being equal, quality of construction, quality of materials, same materials where possible, a fixed blade will be stronger. The folder has 2 points of failure, pivot and lock, that a fixed blade does not. Is a folder weaker from a "practicle" standpoint? I would consider some of the current folders, REKAT, Sebenza, Axis, strong enough that the blade would break before the pivot/lock. Could you damage the pivot/lock effecting the function? Possibly, but I'm looking at breaking the knife as my major concern. As long as it doesn't come apart or fold up on me I'm satisfied.

Take care,

Mike

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TANSTAAFL

 

[Snickersnee]

Marion;

Well first off, as I have said, it's "common knowledge" that "no folder can ever be as strong as a fixed blade". I've been thinking about that, and I've come up with a few scenarios when a folder might have it over a fixed blade, depending on how the two were put together. There is so much erroneous "common knowledge" that I seek to destroy common knowledge where ever I find it.

Another issue is just over-all lock strength, is there really a cap on it? To my mind, if you have something that's good, but you can make it better, you should.

It seems there's all sorts of ways you can play with surface area and mechanics to produce a better, stronger, and more reliable lock.

After all, most people cary a folder instead of a fixed blade, shouldn't you want the best you can get?

I'm not arguing a folder over a fixed blade or anything like that, they both have their own well-defined areas of expertise, just considering the advancement of the folding knife. Trying to see if I can root out any new ideas on locks, which is why I proposed the rather ponderous "vice lock".

 

[Samurai6]

A folder is only as strong as its blade stop pin, usually set in holes in a metal liner, and held in place with a couple of small screws. That cannot ever be quite as strong as a full tang knife, though some of the really beefy ones like on the Darrel Ralph Apogee and Reeve Sebenza are pretty strong, probably strong enough.

The Barry Wood Swing lock is pretty strong. Mike Irie always says that it will never break.

Now if we are talking about prying, that's a different topic altogether. Again, there is not two piece handle held together by pins and screws that will tolerate heavy lateral forces, day in and day out.

Forget it. The best locking folders are strong enough for pretty hard use, but they are not even close to being as strong as a full tang fixed blade. A stick tang might be another question, depending on the handle material and the construction.

Harv

 

[Snickersnee]

Construction, that's the entire point. The lock and handle need only be a hair stronger than the blade; then the blade fails first so functionaly there is no difference in strength.

Not every bladestop need be a pin, and rivets are an alternative to screws. Or even welding for that matter.

Modern machining processes open up all sorts of doors in and of themselves.

I see old prejudices die hard though...

 

[longbow]

Well as I said I used my 1416 last night to dig out a judo point arrow in a stump that I had slain yesterday. I didn't pry side to side but did do a bit of heavy chipping, slicing, and yes some torquing. Bottom line is that although a very robust design for a folder, probably one of the more stout folders I have owned, it is still no match for any type of fixed blade. Clip knives have there place and there use, but can't see getting all fired up about it. For general chores they are fine, even probably butchering an animal down to quarters, at least a deer sized animal, but I for one have serious second thoughts on there use for much more than opening envelopes, slicing and dicing and ocassional dinner up in the kitchen, and field dressing chores of small to medium sized animals. Fixed blades are the way to go as far as I am concerned. Although I do like pocket clips for the convenience. Keep'em sharp

 

[P.J.]

Snick:
How about a lock contact surface of 1/8th of a sq. in. per handle side or a pivot pin of 3/8th in. dia. I know for a fact that a folder can be extremely strong in both up/down and lateral loads as Cliff stated.
Damn, still can't get this picture of the lock to load to a post.

------------------
P.J.
YES,it is sharp, just keep your fingers out of the way!
www.silverstar.com/turnermfg

 

[Marion David Poff]

PJ, Email me and I will help you get the pic up.

Snick,

Hypothetically I agree with you. One could make a lock that would be stronger than the blade and therefore beat out the fixed.

But my point is, that at this time I can see no way to put that hypothetical knife together so that it would be easy to open, quick to lock, light enough to carry and disassemblable to clean. But just because I cannot see it does not make it impossible.

I welcome any ideas you have. I also think that one should contemplate all these things to further the art and science.

May I make a suggestion though? You may want to re-read your posts to see how they might be taken, sometimes you come off a bit inflammatory.

I see old prejudices die hard though...

Cliff, there is the thrill of having a cool gadget in your pocket..... And I carry both, usually two folders and a neck knife. Folders and fixed at the same time.

goshawk, I would love to see that folder you are working on...

------------------
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Check out my review of the Kasper AFCK, thougths on the AFCK and interview of Bob Kasper. <A HREF="http://www.geocities.com/Yosemite/Meadows/1770/kasperafck.html]http://www.geocities.com/Yosemite/Meadows/1770/kasperafck.html[/URL" TARGET=_blank>

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[This message has been edited by Marion David Poff (edited 21 August 1999).]

 

[Snickersnee]

That closing comment wasn't meant to be inflamatory, just saying that it seems many people are turned off to the idea of developing a folder to rival a fixed balde in strength.

As you pointed out, you are limited by design criteria, and not all desirable attributes are compatable.

As some may know, I'm involved in making pre-production(or rather sale) navaja prototypes. I've been trying to refine the lock, and everytime I think I have something new, I find that some other guy beat me to it by a hundred years.

One variant using a bladestop that's integral to the handle and the inherent anti-accidental-opening charachteristics of the clasp lock got me thinking.

Navajas were made vary large, three or four feet open lengths were not unheard of. These were not novelties, but working weapons and tools that were used both for cutting and thrusting. While perhaps not as strong as an equivalent fixed blade, they were certainly strong enough to be used.

I'm working on something that is new, or at least I don't have access to enough navajas to know that someone tried it before, that should be considerably stronger.

It retains the basic appearance and mechanism of the classic clasp lock, but instead of the backspring there's a backlock style locking bar, only with an angled, ratchet-like tooth that interlocks with the gearteeth on the tang. All of which is radioused for strength and reliability. It is held in place by a coil spring from a mousetrap, in addition to the release lever being fashioned and attached in such a way that your grip reinforces the lock.

Because the teeth are angled any force trying to close the blade makes it hold tighter.

The handle itself, if the prototype proves successful, will be machined from a single block of steel. The handle of the navaja was once carved from the solid ends of horns, so the basic pattern is amenable to this style of constuction.

Coupled with the sizable pivot pin that is possible with this pattern, you're looking at a very strong folder that will even resist much lateral stress.

 

[Samurai6]

I am reminded of a time when I was watching Phil Hartsfield doing a rope cutting demonstration at a show. He had a chunk of 3" hawser he was slicing through like a salami. He asked the assembled crowd for a knife to compare with the Kozuka he was demonstrating. The best anybody came up with was an AFCK, which is pretty typical in terms of constructin to most of the "tactical" folding knives today. When Phil was offered the AFCK, he declined because he was afraid he might break it.

It is not just a matter of the blade breaking before the handle. That might be true for lateral force, but for force in the cutting direction, which is the direction knives are designed to withstand force, the stop pin will be first to go just about every time.

Harv