What are the commonly used bolts on cars?

Bolts are the most commonly used parts in cars. Many car mechanics jokingly call themselves "screwdrivers." If you look closely at bolts, you will see that bolts come in various shapes and have different numbers on them. What do these mean? Today we will talk about the knowledge of car bolts.

According to the winding direction of the thread: it is divided into two types: left-hand thread and right-hand thread. The vast majority of threads are right-hand threads, and a few special parts use left-hand threads.

According to the number of threads, it can be divided into single thread, double thread and triple thread. Among them, single thread is mostly used for connection, and the others are mostly used for transmission.

According to the shape of the thread, it is divided into triangular thread, rectangular thread, trapezoidal thread and zigzag thread. Among them, the triangular thread has good self-locking properties and high thread strength. It is generally used for connections and is the most widely used thread. According to the pitch, it is divided into two categories: coarse thread and fine thread. Coarse thread is the basic thread. Fine thread screw has high strength, but the thread strength is lower than coarse thread. It is generally used for thin-walled pipe fittings, shaft parts and precision parts. on the adjustment parts of the mechanism. When the screw diameter is greater than 70mm, only fine threads can be used.