Don't no best place to put this .so I have put it here . help measure the pitch size
If you measure 10mm of thread and count the threads. If you count 8 then it is 1.25 (8 x 1.25 =10)
If you measure 9mm and count 6 then it is 1.5
If you measure 10mm and count 10 then it is 1.0 .