for driving the compressor section of gas turbine engine 10 the heated gases continue through turbine section 12 and are forced through nozzle 16 nozzle 16 increases the velocity of the gases as they exit gas turbine engine 10 in order to produce forward thrust for propelling an aircraft fig2 shows a partially exploded perspective view of cut away turbine section 12 of fig1 showing the assembly of turbine blades 20 a and rotor disc 22 a turbine blades 20 a are radially arranged around the outer circumference of rotor disc 22 a turbine blades 20 a include foil 26 shroud 28 platform 30 and root 32 rotor disc 22 a includes slots 34 aligned along the outer circumference of rotor disc 22 a slots 34 receive roots 32 of turbine blades 20 a slots 34 include serrations 36 and roots 32 include tangs 38 having a matching profile with that of serrations 36 in typical embodiments roots 32 have a u201c fir tree u201d or u201c dove tail u201d configuration as is known in the art roots 32 are inserted into slots 34 the axial direction so tangs 38 are locked into serrations 36 tangs 38 and serrations 36 secure turbine blade 20 a in the radial direction during rotation of rotor disc 22 a and distribute the load produced by the centrifugal momentum of rotating turbine blade 20 a serrations 36 and tangs 38 also allow for thermal expansion of roots 30 and rotor disc 22 a in the extreme temperatures reached in gas turbine engine 10 additionally rivets or other fastening mechanisms are used to hold turbine blades 20 a in the axial direction when turbine blades 20 a are inserted into rotor disc 22 a shrouds 28 align.