ACME Thread Pitch diameter measurement using contact points 1

[Qual7Eng]

Gents,
Please help me to measure the pitch dia. using contact point/balls(dia. 'd') for a stub ACME thread, 24"-2TPI Stub ACME external thread.

 

[3DDave]

https://www.threadcheck.com/the-three-wire-method-of-measuring-pitch-diameter/technicalinfo/

 

[DraftingMan]

[URL unfurl="true"]http://gagemaker.com/products/pitch-diameter/pitch-diameter-gages/[/url]

John H. Dunten, CD
Certified Drafter

 

[mfgenggear]

@qual7eng
you have received two good leads.
just be advised that mfg and inspection have to use the same tooling. be it pitch mics or the same size balls.
otherwise it is possible to get different results.
so what I mean is two different size balls can be calculated for three wire measurement.
but if mfg uses the larger ball and inspection the smaller size ball, the smaller size ball
can and has been undersize to the calculation, there for specify the correct size ball for both
inspection and mfg. seen this happen from experience, it's were each size ball contacts the
acme profile.

 

[JS_]

One more method.

https://flexiblemeasuring.com/