Under the same nominal diameter, the number of teeth per inch varies, which means the pitch is different. The coarse pitch is larger, while the fine pitch is smaller.
Coarse thread refers to standard thread, which is characterized by high strength and good interchangeability. The self-locking performance is poor, and anti-loosening washers, self-locking devices, etc. need to be installed in vibration environments.
Fine thread is generally used to lock thin-walled parts and parts with high anti vibration requirements. The self-locking performance is good, so the ability to resist vibration and prevent loosening is strong. However, due to the shallow depth of the thread teeth, the ability to withstand greater tensile force is worse than that of coarse thread.
