On February 17, 2017 at 00:55, Brad Humphrey said...
Someone did try 2 different size 1/4" but they just said coarse & fine, not what the actual pitch was. But I only know of 20 & 28 tpi for 1/4".
And that's coarse and fine.
I know something about 1/4-20 because I decided A LONG TIME AGO to standardize on that size. Once I found that an F connector used the same wrench as a 1/4-20, that was it! And Togglers come in 1/4-20 to further clinch it.
Although there was a guy that found some 1/4"-18 on a bunch of 1950s windows once:
[Link: tractorbynet.com]Truly oddball. Tractor window bolts.
