🔍 Key Concepts

• Look closely at the top of the set screw labeled F to see what shape the driving recess is. • Match that recess shape to the tool tip shapes: Phillips, spanner, Crescent (adjustable), and Allen (hex key). • Remember that many set screws are designed to be driven from an internal socket rather than an external head.

💭 Think About

• Does the screw in figure F have a slotted or cross-shaped recess, two small pin holes, a hex-shaped internal recess, or flat sides for a wrench to grab? • Which of the listed tools is specifically designed to fit inside a hex-shaped hole rather than around the outside of a bolt head? • Which tool on the list would not work at all on a headless screw whose only driving surface is a recess in the top?

✅ Before You Answer

• Verify the recess shape on the end of screw F (internal hex, slot, cross, or holes). • Eliminate any tools that require flat external faces on a bolt head to grip. • Choose the tool that is purpose‑built to fit an internal hex drive in a headless set screw.