Which type of micrometer is designed for measuring a piece of round stock?

The outside micrometer is specifically designed for measuring the external dimensions of objects, such as the diameter of round stock. Its construction allows for precise measurements by utilizing a calibrated screw mechanism, which translates the movement of the spindle into direct readings on the scale. The outside micrometer's design includes a primary measurement rod and a ratchet mechanism that ensures consistent pressure when measuring various sized items, making it particularly suited for round stock and similar external features.

In contrast, the depth micrometer is utilized for measuring depths, the inside micrometer is intended for measuring the internal dimensions of objects like holes or slots, and the caliper micrometer is designed for general measurements with a broader range than typical micrometers. Thus, these other types do not fulfill the specific requirement needed for accurately measuring round stock, reinforcing why the outside micrometer is the preferred tool in this context.