Which statement about outside micrometers is true?

Which statement about outside micrometers is true?

• A. They measure internal dimensions
• B. They read in fixed units only
• C. They cannot be used for radii
• D. They are used to measure external dimensions

Answer: (D)

Outside micrometers are designed to measure the size of an object’s exterior surfaces. The spindle moves toward a fixed anvil to clamp around the outside of the part, giving you the external dimension, such as outside diameter or thickness. That direct focus on measuring the exterior is what makes this statement true. They aren’t used for internal dimensions (that’s the job of inside micrometers or bore gauges), and they don’t measure radii directly with a single step of reading—their function is to capture straight external dimensions. In practice, you’ll choose the metric or inch version of the tool, but the core idea remains: these gauges measure external dimensions.

Outside micrometers are designed to measure the size of an object’s exterior surfaces. The spindle moves toward a fixed anvil to clamp around the outside of the part, giving you the external dimension, such as outside diameter or thickness. That direct focus on measuring the exterior is what makes this statement true. They aren’t used for internal dimensions (that’s the job of inside micrometers or bore gauges), and they don’t measure radii directly with a single step of reading—their function is to capture straight external dimensions. In practice, you’ll choose the metric or inch version of the tool, but the core idea remains: these gauges measure external dimensions.