Feed rates for milling operations are expressed as __________.

Feed rates for milling operations are typically expressed in inches per minute. This measurement indicates how far the cutting tool moves in relation to the workpiece per minute, which is essential for achieving the desired cutting speed and ensuring efficient material removal. Using inches per minute allows operators to relate the movement of the milling machine to standard measurements commonly used in the United States.

While other units of measurement like millimeters per second or feet per second are used in different contexts or in specific industries, inches per minute remains the most common standard in milling operations, particularly in American manufacturing settings. Revolutions per minute, on the other hand, is a unit used to measure spindle speed rather than the feed rate, which is why it is not suitable for this particular question.