ASTM B385 Specification

Scope

This specification covers unalloyed and alloyed tantalum rod and wire. The materials covered by this specification are: R05200, unalloyed tantalum, electron-beam furnace or vacuum-arc melt, or both, R05400, unalloyed tantalum, powder-metallurgy consolidation, R05255, tantalum alloy, 90 % tantalum 10 % tungsten, electron-beam furnace or vacuum-arc melt, or both, R05252, tantalum alloy, 97.5 % tantalum 2.5 % tungsten, electron-beam furnace or vacuum-arc melt, or both, and R05240 tantalum alloy, 60 % tantalum 40 % columbium, electron-beam furnace or vacuum-arc melt, or both.
The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for
information only.

Chemical Composition

ElementContent, max, % weight Grades
Electron-Beam Cast (R05200) Vacuum-Arc Cast (R05200) Unalloyed TantalumSintered (R05400) Unalloyed TantalumElectron-Beam Cast (R05255) Vacuum-Arc Cast (R05255) 90 % Tantalum 10 % TungstenElectron-Beam Cast (R05252) Vacuum-Arc Cast (R05252) 97.5 % Tantalum 2.5 % TungstenElectron-Beam Cast (R05240) Vacuum-Arc Cast (R05240) 60 % Tantalum 40 % Columbium
c0.0100.0100.0100.0100.010
00.0150.030.0150.0150.020
N0.0100.0100.0100.0100.010
H0.00150.00150.00150.00150.0015
Nb0.100.100.100.5035.0-42.0
Fe0.0100.0100.0100.0100.010
Ti0.0100.0100.0100.0100.010
w0.0500.0509.0-11.02.0-3.50.050
Mo0.0200.0200.0200.0200.020
Si0.0050.0050.0050.0050.005
Ni0.0100.0100.0100.0100.010
Taremainderremainderremainderremainderremainder

Additional Chemical Requirements for Finished Product (When Specified by the Purchaser)

ElementContent, max, % weight Grades
Electron-Beam Cast (R05200) Vacuum-Arc Cast (R05200) Unalloyed TantalumSintered (R05400) Unalloyed TantalumElectron-Beam Cast (R05255) Vacuum-Arc Cast (R05255) 90 % Tantalum 10 % TungstenElectron-Beam Cast (R05252) Vacuum-Arc Cast (R05252) 97.5 % Tantalum 2.5 % TungstenElectron-Beam Cast (R05240) Vacuum-Arc Cast (R05240) 60 % Tantalum 40 % Columbium
O0.0250.0350.0250.0250.025
N0.0100.0100.0100.0100.010
H0.00150.00150.00150.00150.0015
C0.0200.0200.0200.0200.020

Mechanical Properties for Rod and Wire, Annealed Condition

 Rod
0.125 in. (3.18 mm) to 2.5 in. (63.5 mm) Diameter
Ultimate Tensile Strength, min, psi (MPa)Yield Strength, min, psi (MPa)Elongation, min, % 1 in. (25.4 mm) Gage Length
Unalloyed tantalum (R05200 and R05400)25 000 (172)15 000 (103)25
97.5 % tantalum 2.5 % tungsten (R05252)40 000 (276)28 000 (193)20
90 % tantalum 10 % tungsten R0525570 000 (482)55 000 (379)20
60 % tantalum 40 % columbium (R05240)35 000 (244)15 000 (103)25
 Diameter, in. (mm)Ultimate Tensile Strength, min, psi (MPa)Elongation min, %A
Unalloyed tantalum (R05200 and R05400)0.010 (0.254) to 0.0149 (0.379)35 000 (241)10
 0.015 (0.381) to 0.0249 (0.633)35 000 (241)15
 0.025 (0.635) to 0.124 (3.14)30 000 (207)20
97.5 % tantalum 2.5 % tungsten (R05252)0.010 (0.254) to 0.0149 (0.379)40 000 (276)5
 0.015 (0.381) to 0.0249 (0.633)40 000 (276)10
 0.025 (0.635) to 0.124 (3.14)40 000 (276)15
90 % tantalum 10 % tungsten (R05255)0.010 (0.254) to 0.0149 (0.379)70 000 (482)5
 0.015 (0.381) to 0.0249 (0.633)70 000 (482)10
 0.025 (0.635) to 0.124 (3.14)70 000 (482)15
60 % tantalum 40 % columbium (R05240)0.010 (0.254) to 0.014935 000 (244)10
 (0.379) 0.015 (0.381) to 0.0249 (0.633)35 000 (244)15
 0.025 (0.635) to 0.124 (3.14)35 000 (244)20

Note :

A. 10-in. (254-mm) gage length to 0.050 in. (1.27-mm) diameter and 1-in. (25.4-mm) or 2-in. (50.8-mm) gage length over 0.050-in. (1.27-mm) diameter.