To turn a perfect cylinder, the lathe centers must be what?

• A. Lathe centers
• B. Cutting tools
• C. Workpiece
• D. Spindle bearings

Answer: (A)

Accurate center alignment keeps the workpiece rotating true to the spindle axis. When you turn between centers, the ends ride on lathe centers, and those centers must be coaxial with the spindle axis and correctly aligned so the piece spins without wobble. If the centers are not true, the axis runs off-center, producing taper or out-of-roundness as material is cut, so the finished cylinder won’t be perfect. Cutting tools do the shaping, and the workpiece is what’s being shaped, but neither alone guarantees a true cylinder—the rotation must be held true by properly aligned lathe centers. Spindle bearings support rotation but don’t establish the workpiece’s axis.