Followed the Yahoo group intently on the topic of threading.....for a LONG time.
Before .008, the parts I was threading made BEAUTIFUL pictures like all the rest. But getting to the nitty gritty, the were in and out of the specified tolerance.
I purchased precision ring gauges that were certified with a tolerance of +/- .00075 on the PD. (48 TPI)
The parts would come and go, + and - and I would get about 7 or 8 out of 10 good parts on average. TOTALLY unacceptable.
After .008, only a slight variation in the PD, so little that 400 parts were made, every single one checked and ALL were good.
Needless to say, I was pleasantly surprised and impressed. The only variations were most likely mechanically related.
I have 12,000 pieces to run. If this holds up the way it's going now.......well, lets just hope I didn't speak too soon.
Just couldn't hold it in.
Thanks Brian for whatever you did.
RC