A disc of a gas turbine engine system is provided. The disc includes a disc bore including, an interstage coupling disposed on an axially extending surface at a peripheral edge of the disc bore that includes a protrusion that extends axially beyond an outer surface of the disc bore, and a groove formed on the axially extending surface of the disc bore wherein an aft surface of the groove is also a forward surface of the interstage coupling, wherein the groove includes a forward surface that extends radially into the disc bore to a groove floor that is cut into the disc bore and extends axially to the aft surface that extends radially outward to at least the axially extending surface of the disc bore, and a disc web that extends radially outward from the disc bore, relative to an axis of rotation of the gas turbine engine.