Now I'm confused!
The equal spacing of the barrel hash marks would indicate
a standard rolled thread of 40 threads per inch. That works out to one
full rotation of the thimble equaling .025 thousandths of an inch.
The thimble has 25 markings on it to break the rotation down to one thousandths.
If the short hash marks are in tenths the spacing could not possibly be perfectly
centered between the long hash marks. The short hash mark would have to be at
030 or .040 thousandths of an inches. That center difference could be seen from
across the street.
I learn something new here every day!
I need some explanation of how this system works.
Rick
