[s-cars] clutch replacement

[Jerry Scott]

LL
I also do not see the need for TTY.  Why would anyone want to stress a bolt to the yield point.  In my opinion this is very near the failure point of steel.  If they need that much clamping force, why not just go to a larger diameter bolt and stress it within the elastic range. Oh well, it seems to work, since I have never heard of a flywheel failure.  The down side is that the bolts can never be reused.
Jerry
  ----- Original Message ----- 
  From: LL - NY 
  To: Jerry Scott 
  Sent: Wednesday, August 06, 2008 6:13 AM
  Subject: Re: [s-cars] clutch replacement


  Personally, from my Engineering program, I don't understand the purpose of TTY vs. preload at specific torque bolts. I guess due to friction issues, pre-load may be less consistent, but whatever. I've been out of engineering for over a dozen years, and structural issues never became a part of my job, so I never looked into it further. TTY was never in my Shigley's text. 

  LL - NY


  On 8/6/08, Jerry Scott <jerryscott at wispertel.net> wrote:
    Have never heard of a TTY bolt, but I learn something every day.
    Jerry
      ----- Original Message ----- 
      From: LL - NY 
      To: Jerry Scott 
      Cc: Peter Golledge ; s-car list 
      Sent: Tuesday, August 05, 2008 5:51 PM
      Subject: Re: [s-cars] clutch replacement


      By definition, those types of bolts are Torque to Yield (TTY) which means they are torqued to their yield strength and are no longer in the linear portion of their Yield Strength curve, i.e. they are no longer follow Hooke's Law. 

      Cliff's Notes: They can't be reused, 'cuz if done properly before, they've yielded. 

      LL - NY


      On 8/5/08, Jerry Scott <jerryscott at wispertel.net> wrote: 
        As an engineer we learned in school that steel will stretch and return to
        its original length without damage unless you hit the yield point of the
        curve.  So, why can't they be reused as long as they are kept in the Hook's
        law range of the yield?  I don't intend to reuse them, but don't see why
        not.