Personally, I think AICC should be punted over the goal post of so long compliance standards. and some vendors like to offer multiple choices, and yes AICC does different things, but so does driving a moped and I rarely seen people cruising down the interstate on one (unless you live in LA).
Part One: How to Measure Thread Size. 1  In general, the thread should match the fabric in size and weight. For heavier, thicker fabrics, use heavier thread. 2  Heavier threads create more visible stitches. 3  V-69 is the heaviest size recommended for sewing machines. 4  Heavier threads are stronger.
Pipe thread sizes are based on an inside diameter (ID) or flow size. For example, â1/2â14 NPTâ identifies a pipe. thread with a nominal inside diameter of 1/2 inch and 14 threads to the inch, made according to the NPT. standard. If âLHâ is added, the pipe has a left hand thread. The most common global pipe thread forms are: