- Tantalum seamless tube(ASTM B521 - 98 UNS Grade R05200) Tantalum capillary tube/pipe (ASTM B521 - 98 UNS Grade R05200) OD1.0 up to 2.0 mm x WT 0.2 up to 0.35 mm x Length 1 meters max. Tantalum seamless tube/pipe(ASTM B521 - 98 UNS Grade R05200) OD2.0 up to 38 mm x WT 0.2 up to 5 mm x Length 6 meters max. - Tantalum welded tube(ASTM B521 - 98 UNS Grade R05200) OD10 up to 38 mm x WT 0.2 up to 5 mm x Length 6.20 meters max.