Check for not only thread but also nut.
1. Check there is inner thread of nut or not.
2. check the inner thread of aperture，and unloading the OK/NG separately
3. Check the height of nut and the PK/NG gauge the precision 0.05mm
4. Setting the torque according to specification of thread, ach check the thread smoothly or not, and unloading the OK/KG separately.
5. automatic equipment，output value 24pcs/min.