Intro to Millwright Practice Exam

What is the term for a drilled hole that does not pass all the way through the material?

1. Blind Hole

2. Drilled Hole

3. Through Hole

4. Pilot Hole

The correct answer is: Blind Hole

A drilled hole that does not pass all the way through the material is referred to as a blind hole. This term is crucial in machining and manufacturing processes, as it indicates that the hole ends before reaching the opposite surface of the material. Blind holes are often used to create threads, allow for the insertion of components without protruding through, or accommodate fasteners that need to be flush with the material's surface. In contrast, other terms like drilled hole and through hole refer to holes that either pass entirely through the material or are more generic descriptors without specifying the nature of completeness regarding the material's thickness. A pilot hole is a small hole drilled as a guide for a larger hole, which does not necessarily imply any characteristic of being blind or complete. Understanding these distinctions is essential for tasks such as assembly and ensuring proper fit within mechanical systems.