Type of thread

  Thread is used widely in our daily life nowadays; maybe many people want to know the type of thread and their usage. Thread is a common structure of parts and it is the key part of thread connection and screw drive. I will introduce some type of thread to you today.

  According to their usage, thread can be divided to two types: connection thread and transmission thread. Different types of thread have different usage and we will talk about these as follow.

  Connection thread: This type of thread has four kind standard threads, there are coarse thread, fine thread, pipe thread and taper pipe thread. Interestingly, all of their tooth types are triangle. Among them, the tooth type of coarse thread and fine thread are equilateral triangle while others are isosceles triangle. And the pitch and tooth type of pipe thread are smaller than others, it is mainly used in connecting pipe fittings and thin walls parts. 

  Transmission thread: This type of thread is generally used to transform power and motion. And it has two kind standard threads: trapezoidal thread and sawtooth thread. It is universally acknowledged that the most commonly used transmission thread is trapezoidal thread, with a tooth type Angle alpha = 30 °, its tooth type is a isosceles trapezoid. Besides, sawtooth thread is a single way force transmission thread, which make it has a tooth type Angle alpha = 33° and its tooth type is no isosceles trapezoid.

  What is more, only those threads which tooth type, d and pitch can meet the national standards can be called standard thread. Besides the type of thread mentioned above, there are still many kinds of thread are used in our life like rectangle thread. There is no doubt that thread plays an important part in our industrial development.