Which device is used to hold ferromagnetic workpieces in place during setup?

• A. Magnetic base
• B. Vernier caliper
• C. Dial caliper
• D. Micrometer

Answer: (A)

When you need to hold ferromagnetic workpieces during setup, a magnetic base is the best choice because it uses magnetic attraction to secure the part quickly and without clamping. Ferromagnetic materials like steel are attracted to magnets, so placing the workpiece on or against a magnetic base lets you hold it steady while you align, measure, or mark it. The magnetic base provides adjustable positioning and can be attached to a metal table or stand, making setup fast and repeatable without damaging the surface. The other tools are measuring instruments, not gripping devices: vernier and dial calipers measure dimensions, and a micrometer measures small thickness or diameter—none are meant to hold a piece in place.