Rotary broach holders and set-up plugs improve the accuracy of rotary broaches, which produce polygonal shapes in holes. Rotary broach holders secure the broaches to a lathe, milling machine, machining center, or other compatible machine. They hold the centerline of the broach at a 1° angle relative to the centerline of the workpiece so that the broach wobbles to create a shearing effect as it moves into the workpiece. Rotary broach set-up plugs make an indentation on a workpiece to help center a rotary broach as it cuts into the workpiece.