ansi 9standards0 code issues - using a thead for a datum

huangyhg

ansi using a thead for a datum
can you ref a thread as a datum?  
yes. but indicate minor dia for internal thd... or major dia for external thd.
and then you will still have a fun time trying to inspect it.
if possbile, create a small cbore or shoulder to a tight tolerance and use that as the datum instead.  you will have to position the thread to the datum, but the extra step makes inspection much easier.
--scott