×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

How to calculate Buttress Threads stress for a comparison to standard threads?

How to calculate Buttress Threads stress for a comparison to standard threads?

How to calculate Buttress Threads stress for a comparison to standard threads?

(OP)
Hello all

I am trying to calculate the strength advantage of a buttress threaded bolt and nut statically loaded in one thrust direction. I have found several examples for determining the stress's of a square thread, for example Link.

Will these same equations apply? I am having a hard time finding buttress thread specific calculations or equations anywhere. Is this something that will require FEA? . Tips on where to look or start would be greatly appreciated.

Regards,

Robert

RE: How to calculate Buttress Threads stress for a comparison to standard threads?

Hi tweed classic

I believe the only difference is the profile proportions of the thread.
Go to the link below and scroll down you will find what your looking for.

http://www.ejsong.com/mdme/memmods/MEM30009A/lifti...

RE: How to calculate Buttress Threads stress for a comparison to standard threads?

I don't think it is that easy, the first sentence in the section on stress says it all. Thread stress computations are complicated!

The Buttress is a tapered thread form and therefore, equations associated with shear and bending are not the same as those for a straight thread. Several studies from notables in the field, Clinedinst for example, are quite detailed in the analysis and have restricted the study to line pipe threads. None-the-less, the departure from classical methodologies such as that in the ANSI standard, is particularly pronounced. I have included one such paper for your review.

I have found that small adjustments in the numerical values associated with some threads are highly acceptable to field results. Many of my own studies with VAM, Tenaris-Hydril and an inhouse tapered Acme thread form came within 3% theoretical values when using the paradign laid out in the Clinedinst paper. I have not looked at Buttress threads, therefore cannot comment on accuracy. I surmise you would see similar results if pressed to do so, although the assymetry of threading may give larger errors or at least beyond standard scientific error.

Good luck with it.

Regards,
Cockroach

RE: How to calculate Buttress Threads stress for a comparison to standard threads?

(OP)
Thanks
I will review the paper. I really appreciate it.

Cheers

Robert

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources