The following applies to all specified limits in this standard for purposes of determining conformance with this specification: The observed value or a calculated value shall be rounded off to the nearest unit in the last right-hand digit used in expressing the specification limit, in accordance with the rounding-off method of Practice E29.

This specification covers hafnium alloyed niobium ingots prepared by vacuum- or plasma- arc melting or electron-beam furnace melting, or a combination of these methods, to produce consolidated metal for processing to various mill shapes. The material shall conform to the required chemical composition prescribed. Each ingot should be tested for soundness by non-destructive test methods, such as dye penetrant and ultrasonic testing. Each ingot shall be tested for chemical composition in at least three positions along the length of the ingot.