METAL FREITAS DISTRIBUIDORAS DE FERRAGENS LTDA

It is a machine element to keep an axis fixed to other components. It is usually made from a square bar and machined to fit the bottom of the shaft and the transmission component. Thus, this downside gets the name tear of the key.
Keychain is a machine element used to connect a rotating machine element to an axis. The keyway prevents relative rotation between the two parts and can allow torque transmission. For a key to work, the shaft and rotating element of the machine must have a keyway tear and a key. A keyjoint can allow relative axial movement between the parts.

There are several standards for keychain, just the customer choose. Or even the option to manufacture according to the needs of each customer.