Quote:
Originally Posted by _Ogre
orrieg??? calling orrieg 
i believe 55-7 had fine and 58-9 had course or vice versa |
My 59 has fine threads, I believe it is to make it easier to barely loosen for adjustment.
Also "Size for size a fine thread is stronger than a coarse thread . This is both in tension (because of the larger stress area) and shear (because of their larger minor diameter). 2. Fine threads have also less tendency to loosen since the thread incline is smaller and hence so is the off torque" according to my mechanical design textbook.
Do not know if the 55.2-57 had coarse threads or fine.