Inspection of ACME thread flank angle

[ksufocus]

I'm trying to troubleshoot one of our products that uses an ACME thread drive screw to preload a connection. One of the suggestions has been to ensure the flank angles on the threads are correct. What is the best way to measure the flank angle on external and internal threads? Nominal thread sizes vary from 2.5" and up... Thanks!

 

[KENAT]

You can use dental molding paste (or there is a version specially for this kind of thing) to take a cast of the internal thread and inspect it. We used to put it up on a optical comparator.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​