This specification covers unalloyed and alloyed tantalum ingots prepared by vacuum-arc melting, electron-beam melting, or powder-metallurgy consolidation to produce consolidated metal for processing to various mill shapes. The materials covered by this specification are classified according to types: R05200; R05400; R05255; R05252; and R05240. The ingot metal for types R05200, R05255, R05252, and R05240 may be prepared by vacuum-arc melting, electron beam furnace melting, or a combination of these two methods. The metal for type R05400 is defined as powder-metallurgy consolidation unalloyed tantalum. The material shall conform to the chemical composition requirements for carbon, oxygen, nitrogen, hydrogen, niobium, iron, titanium, tungsten, molybdenum, silicon, nickel, and tantalum.

1.1 This specification covers unalloyed and alloyed tantalum ingots prepared by vacuum-arc melting, electron-beam melting, or powder-metallurgy consolidation to produce consolidated metal for processing to various mill shapes.

1.2 The materials covered by this specification are:

1.2.1 R05200, unalloyed tantalum, electron-beam furnace or vacuum-arc melt, or both,

1.2.2 R05400, unalloyed tantalum, powder-metallurgy consolidation,

1.2.3 R05255, tantalum alloy, 90 % tantalum 10 % tungsten, electron-beam furnace or vacuum-arc melt, or both,

1.2.4 R05252, tantalum alloy, 97.5 % tantalum 2.5 % tungsten, electron-beam furnace or vacuum-arc melt, or both, and,

1.2.5 R05240 tantalum alloy, 60 % tantalum 40 % columbium, electron-beam furnace or vacuum-arc melt, or both.

1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.