1.1 This specification covers unalloyed and alloyed tantalum plate, sheet, and strip as follows.1.1.1 R05200, unalloyed tantalum, electron-beam furnace or vacuum-arc melt, or both,1.1.2 R05400, unalloyed tantalum, powder-metallurgy consolidation,1.1.3 R05255, tantalum alloy, 90 % tantalum, 10 % tungsten, electron-beam furnace of vacuum-arc melt, or both,1.1.4 R05252, tantalum alloy, 97.5 % tantalum, 2.5 % tungsten, electron-beam furnace or vacuum-arc melt, or both,