locking device

Hello wellcom back  
the  automoblie  is can use more type of Thread 
To one of these as (B.S.F) Thread 
these thead Angle (55) it happens but B.SW  even than (t.p.i )The nambar is greater 
his called fine thread 
which part in pressur and Vibration stays there over  Does is use B.S.F 

British Standard Pipe thread

these thread angle (50) Stays this thread (B.S.w) ramains the same these thread can use  For pipeline fittings 

british association (B.A)
these  Thread angle (47/1/2) As stays  this thread (1/4) Less Than Diameter Remains 
as like skrow  smole part for can use 
(B.a)