Which tool is typically used to set a divider to an exact dimension?

The machinist scale is commonly used to set a divider to an exact dimension because it provides a precise linear measurement. This tool typically features graduated markings, allowing the user to easily measure and transfer dimensions effectively. By aligning the divider's points with the markings on the scale, the user can accurately set the desired spacing between the dividers.

In contrast, the other tools serve different functions. A dial indicator is primarily used for measuring small distances or variations in measurements with great precision but does not facilitate setting dividers. A thickness gauge is used to measure material thickness, which is not relevant for setting dividers. The surface gauge aids in marking or measuring height and depth on a flat surface but is not specifically designed for setting dimensions in the same way a machinist scale does. Thus, when accuracy in setting dividers is required, the machinist scale is the appropriate choice.