This specification covers iron-chromium-nickel, high-alloy tubes made by the centrifugal casting process intended for use under pressure at high temperatures. The grades of high alloys detailed in Table 1 are intended for applications requiring strength and resistance to corrosion and scaling at high temperatures.Optional Supplementary Requirements S1 to S11 are provided; these call for additional tests to be made if desired. The values stated in inch-pound units are to be regarded as the standard.