A deformable fastener assembly for use with a gas turbine engine. The deformable fastener may be used to fasten a component of the gas turbine that is subjected to high temperatures and thermal deformation, such as an impingement sleeve assembly, to a rigid portion, such as the inner turbine shell of the gas turbine engine. The deformable fastener assemblies may permit components to be fastened to a rigid portion of the gas turbine with a consistent load input to permit frictional transient sliding of the component relative to the rigid portion of the gas turbine engine.