Which hole is larger than the screw's thread and shank?

Which hole is larger than the screw's thread and shank?

• A. Clearance hole
• B. Pilot hole
• C. Countersunk hole
• D. Datum hole

Answer: (A)

Knowing how hole sizes relate to screw sizes is key here. A clearance hole is drilled larger than the screw’s thread major diameter so the screw can pass through the hole without the threads engaging it; the screw then threads into a mating piece with a tapped hole or nut. This ensures smooth alignment and assembly, with the hole simply guiding the bolt rather than receiving the threads. The other hole types serve different purposes: a pilot hole is smaller and helps guide the screw into the material, a countersunk hole fits a flush screw head, and a datum hole is used as a reference feature for alignment. So the hole that is larger than the screw’s thread and shank is the clearance hole.

Knowing how hole sizes relate to screw sizes is key here. A clearance hole is drilled larger than the screw’s thread major diameter so the screw can pass through the hole without the threads engaging it; the screw then threads into a mating piece with a tapped hole or nut. This ensures smooth alignment and assembly, with the hole simply guiding the bolt rather than receiving the threads. The other hole types serve different purposes: a pilot hole is smaller and helps guide the screw into the material, a countersunk hole fits a flush screw head, and a datum hole is used as a reference feature for alignment. So the hole that is larger than the screw’s thread and shank is the clearance hole.