An apparatus and method for machining an aeronautical component

The apparatus 10 for machining at least one spline 205 in an aeronautical component 200 includes a moveable holder 15 defining an axial direction A1. A cutting insert 20 is attachable to the holder. A coupling (25, Figure 2A) attaches the insert to the holder about a second direction A2, perpendicular to the axial direction A1 of the holder. An alternative apparatus includes a coupling for attaching a cutting insert to a holder wherein the holder has a first alignment feature for orientating the insert at a single orientation with respect to the holder. A cutting insert includes a cutting tooth with a cutting edge extending along a length direction and a coupling extending along a perpendicular width direction. A method of machining a spline includes moving apparatus to cut a first portion with a cutting tooth and moving the apparatus to cut a second portion to create a fillet or chamfer on an edge of the spline. A spline-forming apparatus includes a tool holder for a multi-axis cutting machine and a coupling to receive a cutting insert, the insert having a cutting surface geometry corresponding to a desired spline geometry.