1.1 This test method covers the determination of heat stability of steam turbine shafts and rotor forgings to ensure stability at operating temperature. This test method is not ordinarily applicable to generator rotor forgings.1.2 This test method is expressed in both inch-pound unit and in SI units; however, unless the purchase order or contract specifies the applicable M specification designation (SI units), the inch-pound units shall apply. The values stated in either inch-pound uni