Semicircle key

The key bar is a kind of long bar, there are different, a variety of cross-sectional sizes, the key is mainly used as a circumferential fixation between the shaft and the parts on the shaft to transmit torque, and some keys can also realize the axial fixation or axial movement of the parts on the shaft. Keys are divided into flat keys, Semicircle key, wedge keys, tangential keys, and spline keys, etc.