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.
When you find the number of threads per inch, a fractional screw size would be written: diameter-threads per inch. Example: 1/2-20, 1/2 (inch) being the diameter and 20 threads per inch. click on pictures to enlarge. Most hobbyists don t have a thread pitch gauge, so you can use a scale.You can count how many thread crests are in an inch. If the fastener is short, measure how many in a quarter inch, then multiply by 4.he following is what I explain to my students how screw threads are described. Screw threads have two descriptions. One is its diameter, measured to the height of the threads. The other is how many threads per inch. Or, in metric use, the pitch of the threads that is the measurement from one crest to the next.