Coast Guard Exams
Question 3291Deck General70% to pass

A drilling bit which is doughnut shaped to permit recovery of the center portion of the hole drilled is called a _______________.

AI Explanation
The correct answer is D) core bit. A core bit is a doughnut-shaped drilling bit that allows for the recovery of the central portion of the drilled hole, known as the core. This is useful in various applications, such as geological exploration, where the core sample can provide valuable information about the subsurface layers and composition. The other answer choices are incorrect because: A) A hole reamer is a tool used to enlarge the diameter of a pre-existing hole, not to recover the central portion. B) A diverter bit is used to change the direction of a drilling operation, not to recover the core. C) A conventional bit is a standard, solid-faced drill bit that does not have the doughnut shape required to recover the core.

Ready to test your knowledge?