Intro to Millwright Practice Exam

Where does the millwright measure when using an inside micrometer to achieve accuracy?

1. Curved Surfaces

2. Uneven Surfaces

3. Parallel Surfaces

4. Rough Surfaces

The correct answer is: Parallel Surfaces

The accuracy of measurement using an inside micrometer is best achieved when measuring parallel surfaces. This is because inside micrometers are designed to measure the distance between two points within a cylinder or hole, which assumes that the surfaces being measured are parallel to ensure consistent contact and accurate readings. On parallel surfaces, the tool can make uniform contact, providing a reliable measurement of the internal dimensions. This is crucial for applications where precise fitting or alignment is necessary, such as in the installation of bearings, shafts, and other mechanical components. In contrast, measuring curved, uneven, or rough surfaces can introduce variables such as inconsistent contact points and varying distances, which would likely lead to measurement inaccuracies. This is why the focus on parallel surfaces is essential in achieving precision with an inside micrometer.