The slot where a key fits on a shaft is called _________

• A. Key
• B. Keyway
• C. Groove
• D. Spline

Answer: (B)

The slot on the shaft that accepts the key is called the keyway. In a key-and-shaft assembly, a key sits in this slot on the shaft and in a corresponding slot in the mating part (like a gear or pulley), locking them together so torque is transmitted without slipping. The term key refers to the little block that fills the slot, while a groove is a generic slot and a spline involves multiple ridges that mesh with grooves for different drive needs. So the specific slot for the key is the keyway.