Intro to Millwright Practice Exam

What component of a micrometer is essential for measuring the thickness or diameter of small objects?

1. Thimble

2. Anvil

3. Barrel

4. Spindle

The correct answer is: Spindle

The spindle is a crucial component of a micrometer for measuring the thickness or diameter of small objects. It is the part that moves toward or away from the anvil when the micrometer is adjusted. This movement allows the spindle to make contact with the object being measured, thereby providing a precise distance between the spindle and the anvil. The precision of the measurement is largely due to the fine adjustment mechanism that the spindle enables, allowing for very small incremental changes that are vital in accurate measurements. The other components have specific roles but do not directly engage with the measurement process in the same way. The thimble is primarily used to turn and engage the spindle; however, it does not directly impact the measurement accuracy. The anvil serves as a reference point against which measurements are taken but does not move to measure thickness or diameter itself. The barrel, while it houses the thimble and provides visual markings for readings, does not play a direct role in creating the measurement. Thus, the spindle’s function is essential for obtaining accurate measurements.