1.1 This specification covers tantalum and tantalum alloy seamless and welded tubes of the following grades:

1.1.1 UNS Grade R05400 Unalloyed tantalum, powder-metallurgy consolidation,

1.1.2 UNS Grade R05200 Unalloyed tantalum, vacuum melted,

1.1.3 UNS Grade R05252 Tantalum + 2.5 % tungsten alloy, vacuum melted.

1.1.4 UNS Grade R05255 Tantalum + 10 % tungsten alloy, vacuum melted.

1.1.5 UNS Grade R05240 Tantalum alloy, 60 % tantalum, 40 % columbium, electron-beam furnace or vacuum arc melt, or both.

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