Posted by John Eickhof on Thursday, November 04, 2004 at 10:13PM :
In Reply to: what's up with this? posted by jim in n.y. on Thursday, November 04, 2004 at 7:26PM :
S.A.E 'fine' thread was developed for additional threads per inch making more contact between the bolt and nut per inch, thus a stronger hold. Studs are designed generall with different TPI and pitch on each end to prevent backing out when the nut is removed from the fine thread portion on the stud. Also, in cast iron and like materials, the coarse thred seems to bind better. By the way, I had a SNAFU on my towing rig, so Digger and I are leaving for Moab in the morning...