Broaching is one of the most precise and efficient machining processes you’ve probably never noticed. At its core, broaching uses a multi-tooth cutting tool (called a broach) where each successive tooth removes a small amount of material. Instead of a single cutting edge doing all the work, the load is distributed across dozens of progressively taller teeth. This allows the final geometry to be produced in a single pass with extremely high dimensional accuracy and surface finish. There are two primary configurations: linear broaching and rotary broaching. Linear broaching pushes or pulls the tool across or through a workpiece, commonly used for internal features like keyways, splines, and polygonal holes. Rotary broaching, on the other hand, uses a slight angular offset and rotation to generate shapes such as hex drives in softer materials. What makes broaching unique is its predictability. Because the tool geometry fully defines the final shape, variability from operator input is m...