Correct option is D
Center drilling is a process used in lathe operations where a small conical hole is drilled at the end of a workpiece using a center drill. The primary purpose of center drilling is:
1. To provide a starting point for drilling – A center-drilled hole prevents the drill bit from wandering when starting a hole.
2. To enable turning between centers – When machining long workpieces, a center hole allows the workpiece to be supported by a lathe center at both ends, ensuring accurate rotation.
Center drilling ensures accurate alignment and prevents misalignment or deflection during machining, especially in high-precision work.
