thoughts on .....

Discussion in 'General Knife Discussion' started by s.p .c, Jan 27, 2021.

  1. s.p .c

    s.p .c

    Jan 27, 2021
    storing assisted openers . how do you keep them? blade out to reduce stress on torsion bar, or closed?thoughts please.
  2. sabre cat

    sabre cat Basic Member Basic Member

    Jul 4, 2014
    I doubt it makes much difference.

    They are shipped to the retailer with the blade closed. That is good enough for me.
  3. s.p .c

    s.p .c

    Jan 27, 2021
    just thinking a spring stored relaxed will last longer?
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  4. Therom


    Nov 13, 2013
    It should not make such a difference and it is more convenient ;)

    never had any issue will previous 0350
    Black Oak Bladeworks and s.p .c like this.
  5. eveled

    eveled Gold Member Gold Member

    Mar 11, 2016
    Two things wear out springs.

    1 cycling them

    2 forcing them past their limits.
  6. abcdef


    Oct 28, 2005
    Closed, the one I own.
    s.p .c likes this.
  7. sabre cat

    sabre cat Basic Member Basic Member

    Jul 4, 2014
    Like I said, I doubt if it makes much difference. Especially considering that the spring is under tension ether way, open or closed.
  8. NorthernSouthpaw

    NorthernSouthpaw Gold Member Gold Member

    Feb 27, 2014
    On a torsion bar type of assisted opener. The bar is not under stress when open or closed. It is the action of opening, or closing the blade that really provides the tension.
    s.p .c likes this.
  9. sabre cat

    sabre cat Basic Member Basic Member

    Jul 4, 2014
    You must know more about this than I do. I figured that there would be some tension on the spring all the time.

    I guess it just depends on the knife design and the type of spring that’s used.
  10. DocJD


    Jan 29, 2016
    It's the movement / cycling that fatigues a spring NOT storage in tension .

    I have pistol magazines from WWII , still work fine , stored loaded .
  11. NorthernSouthpaw

    NorthernSouthpaw Gold Member Gold Member

    Feb 27, 2014
    Just take apart a Speedsafe Kershaw. Actually all you usually need to do is remove one scale to expose the mechanism. The reason why there is a bit of grease in there is so the bar doesn't rattle while the blade is closed.
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  12. sabre cat

    sabre cat Basic Member Basic Member

    Jul 4, 2014
    I’ve done that. A Kershaw Echelon. Much nicer knife without the spring. Mine rattled even with the grease.
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  13. marrenmiller


    Apr 6, 2017
    Oof, some interesting opinions here. Here's mine:

    Torsion bar assists are under slight tension while closed, and are completely free when open (that's why Kershaw/ZT put grease in their handles to hold the springs from rattling while their AO knives are open). The engineering answer here is that, while cycling from high to low stress does cause the majority of fatigue damage to elastic materials like steel, there's also creep to account for with materials loaded for long periods of time, and this can result in additional strain, and therefore damage, to a spring.

    Whether this is matters for most users in the context of the lifespan of a knife is questionable. But there is some difference, even if it's largely academic in this case.

    To (sort of) answer your actual question, I don't leave assisted knives stored in any way because I always pull the springs out and throw them in a box. If I did store an assisted knife, it would be closed.
    Last edited: Jan 28, 2021
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  14. marrenmiller


    Apr 6, 2017
    You have this backwards. The springs are at rest when the knife is open, not closed. I've taken a bunch of these apart and learned the hard way when removing the grease. Also, the spring is what provides the detent force on most AO Kershaws, and that fact alone indicates that the spring is preloaded.
    Last edited: Jan 28, 2021
  15. s.p .c

    s.p .c

    Jan 27, 2021
    would you happen to have a 0350 spring in that box of yours that you would be willing to post?happy to pay
    for spring and post
  16. skyhorse

    skyhorse Gold Member Gold Member

    Jan 30, 2010
    Give Kershaw a call and they'll send you a spring free of charge . A great company :)
    marrenmiller likes this.
  17. Shorttime


    Oct 16, 2011
    I keep them with the spring element stored separately, in a little bag with a label saying what knife it belongs to! :p

    Or, I did. The two(?) AO knives that I do have, are in their boxes, waiting for me to take pictures so I can sell them.

    When I did use and carry them, I wondered about this, too. I found the same information that others have supplied, which is that cycling, not storage, is what causes wear.
    s.p .c likes this.
  18. DMG

    DMG Gold Member Gold Member

    Dec 30, 2005

    No. As long as the spring is not at or near it’s elastic limits, it will be fine pretty much forever. I have seen video of pistol magazines loaded for approaching 100 years that function fine.
    Last edited: Jan 28, 2021
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  19. MarkN86


    Sep 3, 2012
    I used to flip and play with mine constantly and I kept breaking the torsion bars. I stopped doing that and give them some time to rest between firings and it seems like they are lasting longer.. is that in my head or is that possibly a thing?

    If Kershaw would start putting a detent hole in the all blades so they could be deassisted and they would stay closed in the event of a spring failure I doubt anyone would complain. It's such a small step that literally everyone else does on every other liner lock, and it would be such a benefit. I've been on this soapbox for years and I have no idea why they won't start doing it. Great knives hamstrung by one glaring flaw.
    s.p .c likes this.
  20. Black Oak Bladeworks

    Black Oak Bladeworks KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jun 5, 2019
    All the above post nail it in my opinion and research. Springs don't wear out from constant tension, its the compression/un compressing that wears them out or bending them past the limits.
    DocJD, s.p .c and DMG like this.

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