UNJ Thread Fatigue Data

[1deseng]

Does anyone know where I can get thread fatigue data/curves for internal and external UNJ threads? The only data we have been provided by our customer is from the UK with no reference to thread type. Thanks in advance for the help.

 

[CoryPad]

ASTM STP 1236 & 1391 Structural Integrity of Fasteners: 188 page and 214 page Special Technical Publications with contributions on Fatigue, Failure Evaluation and Criteria, Fracture Mechanics, Structural Integrity Criteria, Analysis Techniques, and Testing Procedures. These STP's are available from ASTM International at:

http://www.astm.org

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[diamondjim]

http://www.uscti.com/TapsFinal2.pdf

If you have thread fatigue data curves
for other threads, the internal thread
would be the same as no radius is required
for internal threads. The outer threads
because of the root radius would have
a better thread life or curve.

The above url is a good site for thread info.

 

[1deseng]

Thanks CoryPad and diamondjim. I had previously looked at FAT731-376. It was not clear if ASTM STP 1236 and 1391 included UNJ threads in addition to UNC and UNF threads. We have ASME B1.15-1996, so we have all the geometry for UNJ threads, but we do not have a way right now to determien fatigue life of threaded connections. Thanks again for the help.

Chad Hendrix

 

[unclesyd]

Have you taken a look at the site posted by metengr.

http://www.fatiguecalculator.com/index.htm

 

[1deseng]

unclesyd

I had not run across that in my internet searches. It looks interesting and may be useful. Thanks for the help.

Chad Hendrix

 

[unclesyd]

Chased down some old links. I didn't have them in my favorites came from a file, too much typing that has to be correct.

Here is table that has some fatigue loading values for Grade 8 bolts, unknown thread form.

http://www.avonbearings.com/Engineering/fastener.htm

Another article I had marked.

http://www.machinedesign.com/ASP/viewSelectedArticle.asp?strArticleId=57766&strSite=MDSite&catId=0

Interesting articles. Look at (67020)

http://aerade.cranfield.ac.uk/subject-listing/esdu/ES171.html