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'''% niobium, electron-beam furnace, vacuum arc melt, or both.

1.2''The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.3''This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.