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.