I'm intrigued, what thread is it, it isn't a fraction imperial screw but with imperial pitch. Not 2 B.A as that is smaller in diameter and 0 B.A is larger. I have never come across a 1 B.A. but it is a size I know?
I know its not a 12-28 or a 10-28 the thread is in between them. So i miked the old screw dia and it was .207 and measured over 3 wires (.024 wires) it was .224 if i remember correctly. So i just made the new one to match and it fit right in...Bob
your 12-28 and 10-28 are not threads we are familiar with over here. My thought is that the true diameter (theoretical) would actually be more like .210" or maybe a shade more as threads are rarely made to 100% size, but I guess that as it works that is all that matters.
Must check my thread tables tomorrow to see if it is listed there.