What is a semicircle key

The semicircle key is shaped like a semicircle and can swing in the keyway to adapt to the shape of the bottom surface of the hub keyway. It is commonly used for connecting tapered shaft ends and in situations where the working load of the connection is not high. Like a tapered shaft head, it drives a regular A-belt pulley to rotate through the connection of a semicircle key.
A semicircular key is a type of key, with a flat upper surface and a semicircular curved lower surface, with parallel sides, commonly known as a crescent key.
It has the same connection method as a flat key, but it is more convenient to manufacture and disassemble than a flat key, especially suitable for connecting tapered shafts and wheel hubs. Its disadvantage is that it weakens the strength of the shaft and is generally only used in areas with less stress