Changing round holes into a square shape more accurately than traditional push broaches, these broaches go in CNC and milling machines. Use them with a rotary broach holder (sold separately), which slightly angles the broach so only one corner is cutting at a time. The square holes these broaches cut are good for holding square shafts in finished parts. They work on through holes as well as blind holes, which don’t go all the way through. If you’re cutting soft material, don’t have a CNC or milling machine, or don’t need accuracy, use these broaches in the traditional push style, without the holder.