Tantalum is specified where titanium and the nickel alloys have already been ruled out: hot concentrated acids that attack passive oxide films rather than sit on them. It is bought late in a selection process, and the enquiry that follows is usually about form and length rather than about whether the metal will hold.
Where tantalum starts, in selection terms
Tantalum holds chemical stability where cheaper wetted materials stop, which is why it appears in acid recovery, in heat transfer surfaces inside reactors, and in bayonet heaters rather than in bulk pipework. Tantalum is not a general upgrade from titanium. Titanium is chosen for chlorides and seawater; tantalum is chosen where the acid is hot and concentrated enough that a titanium oxide film no longer survives. The price difference is large enough that a part titanium can hold should stay on titanium.
The supply envelope, by form
Beiyu Titanium supplies tantalum in four forms, and the length limits differ enough between them to matter at the drawing stage:
| Form | Supply range |
|---|---|
| Plate and sheet | 0.03 to 10 mm thick, 30 to 1000 mm wide, 30 to 2000 mm long |
| Round bar | Ø3.0 to 100 mm, length to 3000 mm |
| Wire | Ø0.3 to 3.0 mm |
| Pipe | Ø2.0 to 100 mm, length to 12000 mm |
The pipe row is the one to read carefully on a multi-metal enquiry. Tantalum pipe runs to 12000 mm, while niobium pipe in the same supply range runs to 8000 mm; the two are often quoted side by side and the length limits are not the same. A drawing that assumes one figure covers both refractory metals will come back short.
Grades, and how they are ordered
Three tantalum grades are carried, and the alloying is inside the grade designation rather than being a separate order line:
| UNS number | Composition |
|---|---|
| R05200 | Unalloyed tantalum |
| R05252 | Ta-2.5W |
| R05255 | Ta-10W |
Because the tungsten content travels with the grade name, R05252 and R05255 are ordered by number rather than by a requested percentage. Tantalum is quoted with a density of 16.69 g/cm³ and a melting point of 2996 °C, which are the figures the Beiyu Titanium weight calculator and quotations run on, so a weight estimate taken from this page matches the one that comes back on a quotation.
The specifications named for tantalum
Three specifications are named against tantalum in the supply range: ASTM B708, ASTM B365 and ASTM B521. They are listed once for the metal and cover every form together rather than one specification per form, so this page states them at metal level and does not pair one with plate or with pipe. Which of them governs a given order is named on the order, and that choice belongs in the buyer’s design documents rather than in a supplier’s catalogue.
What a tantalum enquiry has to state
Five of these are the usual order fields. The one that is easy to skip is the service line, and it is the one that decides whether tantalum is the right metal at all.
| Field | Why it decides the quotation |
|---|---|
| Form and dimensions | The four forms have different envelopes, and pipe length differs from niobium |
| Grade by UNS number | R05200, R05252 or R05255; tungsten content is not a separate line |
| Governing specification | ASTM B708, B365 or B521 as the drawing names |
| Service medium, concentration and temperature | Confirms tantalum is the right answer rather than an expensive one |
| Fabrication intent | Whether the part is formed, welded or lined changes the starting form |
| Inspection and documentation scope | What the certificate has to report |
The service line is worth filling in even though it is not a dimension. Tantalum enquiries that arrive as a bare parts list are frequently parts that titanium or a nickel alloy would hold, and confirming the medium early is cheaper for the buyer than confirming it after quotation.
Specification detail with sources
Every figure on this page comes from the Beiyu Titanium supply ranges, read one row at a time. Tantalum plate and sheet run 0.03 to 10 mm thick in widths of 30 to 1000 mm and lengths of 30 to 2000 mm; round bar runs Ø3.0 to 100 mm in lengths to 3000 mm; wire runs Ø0.3 to 3.0 mm; and pipe runs Ø2.0 to 100 mm in lengths to 12000 mm. The three grades carried are the UNS designations R05200, R05252 at Ta-2.5W and R05255 at Ta-10W, and the metal is quoted at 16.69 g/cm³ and 2996 °C.
The specifications published alongside those ranges are ASTM B708, B365 and B521. All three sit in one entry covering every tantalum form. Choosing which governs a pipe order is therefore a design decision, not something the entry settles, and this page leaves it there. Certification is EN 10204 3.1 to the scope the order names.