Purpose This specification covers procedures for ultrasonic immersion inspection of premium grade wrought titanium and titanium alloy round billet 5.0 inches (127 mm) and over in nominal diameter. Application This inspection procedure has been used typically for locating internal defects such as cracks@ voids@ inclusions@ and other structural discontinuities which may or may not be exposed to the surface in billets@ but usage is not limited to such applications. Testing normally will be by longitudinal procedure@ but shear wave procedure may be added when agreed upon by purchaser and vendor. This specification includes zoned inspectionswith single element transducers or with a phased array transducer. Method 1 ?C Single element transducers@ with single or multiple zones Method 2 ?C Phased array transducers When the method is not specified@ selection is at the discretion of the supplier. Class A ?C Acceptance based on signal-to-noise and amplitude (See Table 1A) Class B and C ?C Acceptance based on amplitude only (See Table 1A) Other acceptance levels may be called out by the cognizant engineering organization (CEO) which may include nearsurface hole depth@ calibration FBH size@ calibration amplitude@ maximum acceptable amplitude@ maxium acceptable signal-to-noise ratio@ and data recording method.