Stud Bolt & Heavy Hex Nut Standard
Stud Bolt & Heavy Hex Nut Standard
(OP)
Can somebody answer this question for me? Let's say for this example we are using two 4" NPS 150# RFWN flanges.
Once the flanges are bolted together is it standard for the the nuts to be flush with the edge of the bolt? Or should the threads of the bolt protrude the outer edge of the nut by a couple threads?
Reason I am asking is because a client is requesting longer stud bolts with their projects because they say installation is more difficult with standard size bolts because once everything is mounted together, the nuts and bolts are flush. I have looked at the charts in ASME B16.5 for bolt lengths and ASME B18.2.2 for thickness of nuts and done the math with an 1/8" gasket in between the flanges, and the found that the stud bolts are indeed flush with the nuts. Just trying to figure out if this is standard or if there are supposed to be stud bolt threads protruding out on either side of the nut.
Thanks for the help.
Once the flanges are bolted together is it standard for the the nuts to be flush with the edge of the bolt? Or should the threads of the bolt protrude the outer edge of the nut by a couple threads?
Reason I am asking is because a client is requesting longer stud bolts with their projects because they say installation is more difficult with standard size bolts because once everything is mounted together, the nuts and bolts are flush. I have looked at the charts in ASME B16.5 for bolt lengths and ASME B18.2.2 for thickness of nuts and done the math with an 1/8" gasket in between the flanges, and the found that the stud bolts are indeed flush with the nuts. Just trying to figure out if this is standard or if there are supposed to be stud bolt threads protruding out on either side of the nut.
Thanks for the help.





RE: Stud Bolt & Heavy Hex Nut Standard
ASME Sec VIII Div. 1 - UG-13: "they shall engage the threads for the full depth of the nut".
ASME B31.3: 335.2.3 - "Bolts should extend completely through their nuts. Any that fail to do so are considered acceptably engaged if the lack of complete engagement is not more than one thread."
RE: Stud Bolt & Heavy Hex Nut Standard
You dont want it to be flush, though it's not incorrect. The threads after the nut however still experience bolt assembly stress, and for certain size/pound class combinations (warren brown has written a nice PVP article on this 2013) this is more important than others. Too big of a length is not incorrect as well but esthetically not preferred.