Question for Jimmy concerning omega springs

3

357snubnose

Joined
Jul 1, 2013
Messages
331
How often do you see broken omega springs that don't have some kind of rust or corrosion? I realize that any spring can fatigue and break, but I don't understand why some users have multiple springs break whereas many others (including myself) never have even one break. Can you give us your thoughts here?

Note, I flip my knives open and shut constantly so its not like my springs don't get used.
 
Same experience on my side, never had issues with omega springs Aince I got my first BM 4 years ago
 
Just a pure speculation, as I don't own a Benchmade yet.
My sweat seems quite corrosive, enough to damage plastic casing of a few laptop computers (where I rest my palm).
Others may not.
 
I do lube my omega springs. Not sure if that helps but haven't broken a spring yet on the few I still have. There could be a multitude of reasons why they break from metallurgy to manufacturing to gauge of the wire and corrosion.
 
miso2 said:
My sweat seems quite corrosive, enough to damage plastic casing of a few laptop computers (where I rest my palm).
Click to expand...
Dude !
You may have some kind of latent super powers that you may be unaware of. Like The Silver Surfer or something.
 
Wowbagger said:
Dude !
You may have some kind of latent super powers that you may be unaware of. Like The Silver Surfer or something.
Click to expand...
naw its just salt and acidic effect of folks who sweat like that. i have the same toxic sweat. i touch something and it can leave an etch if i dont clean it off. i sweat pure salt it seems.

never had an omega spring break on me yet, knock on wood.
 
I haven't had an omega spring break on my BM's. However, it's my understanding that the more you use a spring,the faster it wears out.

I don't know the energy that is imparted on the spring each time the Axis lock is actuated. However, if you've ever bent a paper clip many times quickly, it heats up the bend point enough to burn skin, and eventually breaks. Although springs should resist this to a certain extent, I would assume that constant flicking (as in over and over, quickly without stopping, for 10-20 minutes at a time) might induce wear that might equate to decades of use. Just a theory.
 
Corrosion is probably the biggest factor causing the omega springs to break. When we see broken springs they tend to have some corrosion on them. However they can fatigue over time if you are fidgeting with your knife daily but this is still fairly rare. Keep the springs dry and you should be good.
 
miso2 said:
Just a pure speculation, as I don't own a Benchmade yet.
My sweat seems quite corrosive, enough to damage plastic casing of a few laptop computers (where I rest my palm).
Others may not.
Click to expand...
There are people out there that can make S90V rust like it was bead blasted 1095. We had one such individual here long ago, he has moved on though.
 
Scott321 said:
it's my understanding that the more you use a spring,the faster it wears out.
Click to expand...

And all that about bending the paper clip.

You are confusing elastic limits with plastic limits. (plastic means you bent/distorted the material past the point it won't return to it's original shape)(this takes a huge amount of effort compared to just flexing the spring within its elastic limits)

Essentially steel, especially alloy steel or carbon steel as opposed to but including mild steel, has an infinite fatigue life within it's elastic limits.
Aluminum . . . well . . . nah dude, nah.
Link<<
Failure in a steel component is a result of a flaw. A flaw can be in the form of a stress riser in or on the part, a scratch or notch or impurity in the metal, or taking the part past it's elastic limit into the plastic limit . . . bending it out of shape and putting it back into shape etc. This can even be done several times before failure. Steel is a marvelous material where resistance to fatigue and forgiveness of damage is concerned.
 
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Benchmade said:
Corrosion is probably the biggest factor causing the omega springs to break. When we see broken springs they tend to have some corrosion on them. However they can fatigue over time if you are fidgeting with your knife daily but this is still fairly rare. Keep the springs dry and you should be good.
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It would be fascinating to learn where on the length of the spring is the most common point of failure.

Hey . . . I'm on your side. I have never had a Benchmade spring fail.
I have not only caused but studied many, many, many, many failures in steel components so I have a very good idea of what causes structural failure in steel components (and aluminum).

Case in point I designed and built (brass brazed, silver brazed and TIG welded) my own chrome molly steel commuter bicycle from Italian Columbus steel tubing (the lightest/thinest tubes they offered at the time "SL" and it has been used on a daily basis for 30 plus years with no failure. I rode a much lesser quality steel frame with much thicker alloy steel tubing "high tensile" often riding both bikes on the same day or at least certainly both in the same week. The latter frame failed after thirty years some five years ago due to flaws in the design and construction . . . again it was a lower price production frame; not of the highest quality.

I designed the former with an eye toward eliminating stress risers and spreading flexure evenly through key high stress joints.
 
Wowbagger said:
And all that about bending the paper clip.

You are confusing elastic limits with plastic limits. (plastic means you bent/distorted the material past the point it won't return to it's original shape)(this takes a huge amount of effort compared to just flexing the spring within its elastic limits)

Essentially steel, especially alloy steel or carbon steel as opposed to but including mild steel, has an infinite fatigue life within it's elastic limits.
Aluminum . . . well . . . nah dude, nah.
Link<<
Failure in a steel component is a result of a flaw. A flaw can be in the form of a stress riser in or on the part, a scratch or notch or impurity in the metal, or taking the part past it's elastic limit into the plastic limit . . . bending it out of shape and putting it back into shape etc. This can even be done several times before failure. Steel is a marvelous material where resistance to fatigue and forgiveness of damage is concerned.
Click to expand...

Perhaps my paper clip bending example is incorrect. However, it's my understanding that a real-world spring, without any significant defects in craftsmanship, suffers failure over long periods of use due to metal fatigue, which (assuming proper QC and maintenance) can be attributed to the accumulation of "microcracks" over it's lifetime. This would necessitate the idea that the metal does not have an infinite fatigue life within it's elastic limits in real life, but would appear infinite if the number of cycles were significantly less than the actual lifespan. Similarly, I would also assume that any issues with quality control or additional factors related to corrosion would also significantly decrease the life span of the spring.
 
Scott321 said:
a real-world spring, without any significant defects in craftsmanship, suffers failure over long periods of use due to metal fatigue,
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Any documented cases you can link to ?
Think of a valve spring in an automobile engine. The engine is doing on average around 3,000 revolutions per minute (3,000 very significant flexures to the spring(s) per minute in an environment that is easily hundreds of degrees F for hours and hours . . .
How many minutes does it take to drive across the US continent?
And yet with all those ?billions and billions? of cycles valve springs can last for the life of the automobile. Failure comes in the form of valve guide wear and piston ring wear and bearing wear.
Those valve springs ? ? ? Still looking good. :thumbsup:
:)
 
Wowbagger said:
Any documented cases you can link to ?
Think of a valve spring in an automobile engine...
:)
Click to expand...

OK... I like conversations that teach me new things. I get that the endurance limit dictates infinite cycles now (after doing a little research). I do not know how BM tested their Omega Springs, but I'm assuming they have that in order. Therefore, it would seem that the metal fatigue should be due to a defect in the metal of the spring.

However, using your valve spring example... under high stress, many race car teams, i.e. in NASCAR, replace their valve springs after every race. I was asserting that overuse of the Axis lock mechanism might be considered higher stress, but after reading about endurance limits, I see that that might not make sense. I'm also wondering then, why springs, such as in a firearm, should be replaced after so many rounds fired.
 
Like many others have reported, I've never had an omega spring failure in 30+ AXIS lock Benchmades since 2005. I am interested in Jimmy's answer, though. Since this issue seems to keep coming up every so often in the BM forum, it would be interesting to know what Benchmade is seeing when they have to replace failed omega springs.
 
Jimmy -

Regarding broken Axis Springs, which I no longer experience, I was 2x told the following, from two different Benchmade sources. Is the following in accordance with your understanding or opinion:

For proper usage and optimal, or perhaps perpetual longevity, both sides of the Axis Lock's protruding barbell are designed and intended to be simultaneously "pinched" between two (2) fingers and pulled down applying equal pressure to both sides of the Axis bar, in unison.

Whereas, pulling down and applying pressure to only one (1) side of the Axis bar with one's thumb or other finger, subjects Omega Springs to undue stress from the excesssive force of unilaterally shouldering a burden that was instead designed to be shared and balanced by both sides of the Axis bar.

Thanks!
 
Our omega springs will fatigue and fail over time. We have tested it. It takes a ton of cycles though.
 
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