What is a Knee Mill? - wiseGEEK
Parker Brown Man with a drill . A knee mill is a type of vertical milling machine where instead of the entire table being stationary, it is able to move along the y, or vertical, axis, a direction in which the workpiece can move in relation to the milling tool shaping it. This is different from standard milling machines, where the table can only move along both x, or horizontal, axises,