🔍 Key Concepts

• Coupling to shaft connection methods on rotating machinery • Function and shape of a keyway / key seat versus a set screw or lock washer • How torque is transmitted between the shaft and the coupling without slipping

💭 Think About

• Look closely at the region where the coupling meets the shaft: what machined feature do you see in the shaft and coupling bore? • Which of the listed items actually prevents relative rotation between the coupling and the shaft, rather than just preventing axial movement or nut loosening? • In pump shaft designs like this, what common, reusable component is fitted into matching slots to lock two parts together in rotation?

✅ Before You Answer

• Identify any rectangular slot or groove in both the shaft and the coupling hub in the illustration. • Decide which choice is specifically designed to transmit torque between a shaft and a hub. • Eliminate items that mainly serve as locking or safety devices for nuts/bolts rather than as primary rotational locks between shaft and coupling.