🔍 Key Concepts

• Set screw versus regular bolt or cap screw • How couplings are locked onto a shaft (keys, set screws, tapers) • Difference between fastening two flanges together and locking one part on a shaft

💭 Think About

• Look closely at device F: does it have a head that would bear on an external surface, or is it designed to sit entirely below the surface in a tapped hole? • Which of the choices involves holding one rotating part onto a shaft where you often don’t want a projecting head? • Which tasks in the choices normally use full‑headed bolts, nuts, or studs rather than a headless screw?

✅ Before You Answer

• Verify that device F is fully threaded and headless with only an internal drive at one end. • Recall that pump casing flanges and motor frames to bedplates are usually joined with standard bolts or studs plus nuts, not headless screws. • Think about how a coupling half is prevented from slipping on a smooth shaft and what kind of screw is commonly tightened radially against the shaft.