Aspects of the disclosure are directed to a gas turbine engine shaft, having an outer circumferential surface that circumscribes a central axis. The gas turbine engine shaft may comprise a plurality of splines extending along a portion of the outer circumferential surface, where each of the plurality of splines comprises an axial face that tapers from the outer circumferential surface to a spline top surface and includes a curved chamfered surface at a radially distal end of the axial face. The plurality of splines may further comprise a first sidewall and a second sidewall separated by a first spline width distance along the outer circumferential surface, where the first and second sidewalls taper inwardly from the outer circumferential surface to a second spline width along the spline top surface where the second spline width distance is less than the first spline width distance.