bolt and nut fasteners thread engagement
bolt and nut fasteners thread engagement
(OP)
I need to know how many threads are required for proper engagement of a nut. I was told it must be full thread value to meet manufatures spec. any one know whrer i can find it in writing.
Thanks Inspectionboss
Thanks Inspectionboss





RE: bolt and nut fasteners thread engagement
In the meantime, regardless of the physical requirements (one reference I recall allowed the end of the bolt/stud to be one thread "shy" of the face of the nut. Perhaps we'll hear more from other forum members), I recommend at least one thread projecting past the face of the nut.
As the piping QA/QC inspector who shared this tip with me said, "I can verify one thread sticking out from ten feet (or more) away. To see flush or one thread back, I need to be within ten inches."
Donf
RE: bolt and nut fasteners thread engagement
Specifications for Structural Joints Using ASTM A325 and A490 Bolts by the Research Council on Structural Connections
www.boltcouncil.org/download/RCSC Specification 6-23-2000.pdf
RE: bolt and nut fasteners thread engagement
RE: bolt and nut fasteners thread engagement
I think it answers all of your questions.
h
Regards,
M-J
RE: bolt and nut fasteners thread engagement
RE: bolt and nut fasteners thread engagement
http://www.kirsner.org/pages/forensicResAlt.html
There's one of a Class 150 flanged joint failure where the nuts have been stripped off the studs by the water hammer event, and the operator was killed. If I was tangled-up in that investigation, I'd hate to be involved in the "one thread back of the nut and/or flush with the nut is OK" VS. the "one thread past the nut is required" arguement. I'd rather be able to say that the proper size & grade of studs & nuts were used, and ALL of the available threads were fully engaged.
RE: bolt and nut fasteners thread engagement
108.5.1 says in part: "Bolts and bolt studs shall extend completely through the nuts."
RE: bolt and nut fasteners thread engagement
Steve
RE: bolt and nut fasteners thread engagement
TBP - That's an interesting picture (I also like to see goo dfailure pictures). However, simple calculations, such as that shown by Mb17 would conclusively answer whether the failure woudl have occured regardless of thread engagement.
Mb17 - I have used that calculation in the past.
Since this is an engineering forum, has anyone performed any engineering calculations on typical ASME B1.1 bolts/nuts found in refinery/powerplant applications. I've just about had enough of these hand-waving arguments regarding thread engagement.
SHOW ME THE MATH!
RE: bolt and nut fasteners thread engagement
RE: bolt and nut fasteners thread engagement
http://www.hexagon.de/dose/dose1e.htm
RE: bolt and nut fasteners thread engagement
RE: bolt and nut fasteners thread engagement
jt
RE: bolt and nut fasteners thread engagement
Here is an analysis that has a lot of information, a little different and very simple, on thread pull out. Look at 3.2 on page 11. (Hard-Link}
wind.nrel.gov/amestest/StressAnalysisDocument.pdf
This report has a very good format for the newer engineer.