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ASTM B365, ASTM B708:
Additional Chemical Requirements for Finished Product*
(When specified by the purchaser)
Content, Maximum % Weight Grades
Element	Electron-Beam Cast	Sintered	Electron-Beam Cast	Electron-Beam Cast	Electron-Beam Cast
	(R05200)	(R05400)	(R05255)	(R05252)	(R05240)
	Unalloyed Tantalum	Unalloyed Tantalum	90% Tantalum	97% Tantalum	60% Tantalum
			10% Tungsten	2.5% Tungsten	40% Niobium
Oxygen	0.025	0.035	0.025	0.025	0.025
Nitrogen	0.01	0.01	0.01	0.01	0.01
Carbon	0.0015	0.0015	0.0015	0.0015	0.0015
Hydrogen	0.02	0.02	0.02	0.02	0.02
*Certifiable per ASTM B365 and B708, report values for ASTM B521
ASTM B364, ASTM B365, ASTM B521, ASTM B708:
Chemical Requirements for Tantalum and Tantalum Alloy Ingots
(Content, Maximum Weight %)
Element	Electron Beam Cast (R05200)	Sintered (R05400)	Electron Beam Cast (R05255)	Electron Beam Cast (R05252)	Electron Beam Cast (R05240)
	Unalloyed   Tantalum	Unalloyed Tantalum	90% Ta 10% W	97.5% Ta 2.5% W	60% Ta 40% Nb
Carbon	0.01	0.01	0.01	0.01	0.01
Oxygen	0.015	0.03	0.015	0.015	0.02
Nitrogen	0.01	0.01	0.01	0.01	0.01
Hydrogen	0.0015	0.0015	0.0015	0.0015	0.0015
Niobium	0.1	0.1	0.1	0.5	35.0-42.0
Fe (Iron)	0.01	0.01	0.1	0.01	0.01
Titanium	0.01	0.01	0.1	0.01	0.01
W(Tungsten)	0.05	0.05	9.0-11.0	2.0-3.5	0.05
Molybdenum	0.02	0.02	0.02	0.02	0.02
Silicon	0.005	0.005	0.005	0.005	0.005
Nickel	0.01	0.01	0.01	0.01	0.01
Tantalum	remainder	remainder	remainder	remainder	remainder
ASTM B 364	covers unalloyed and alloyed tantalum ingots prepared by vacuum-arc
	melting, electron-beam melting, or powder-metallurgy consolidation to
	produce consolidated metal for processing to various mill shapes.
ASTM B 365	covers unalloyed and alloyed tantalum rod, tantalum wire.
ASTM B 521	covers tantalum and tantalum alloy seamless and welded tubes.
ASTM F 560	covers the chemical, mechanical, and metallurgical requirements for
	unalloyed tantalum plate, tantalum sheet, tantalum strip, tantalum rod,
	and tantalum wire used in the manufacture of surgical implants;
	referenced Practice for Assessment of Compatibility of Biomaterials for
	Surgical Implants with Respect to Effect of Materials on Muscle and Bone.
ASTM B 708	covers unalloyed and alloyed tantalum plate, tantalum sheet;
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;
R05240	tantalum alloy, 60 % tantalum 40 % columbium,electron-beam furnace or vacuum-arc melt, or both;

ASTM B391, B392, B393, B394:
Chemical Requirements for Nb and Nb Alloy Nb1Zr
(Maximum Weight %)
Element	Type 1	Type 2	Type 3	Type 4
	Reactor Grade	Commercial Grade	Reactor Grade	Commercial Grade
	Unalloyed Niobium	Unalloyed Niobium	Nb 1% Zirconium	Nb 1% Zirconium
	R04200	R04210	R04251	R04261
Carbon	0.01	0.01	0.01	0.01
Nitrogen	0.01	0.01	0.01	0.01
Oxygen	0.015	0.025	0.015	0.025
Hydrogen	0.0015	0.0015	0.0015	0.0015
Zirconium	0.02	0.02	0.8 to 1.2	0.8 to 1.2
Tantalum	0.01	0.2	0.1	0.5
Iron	0.005	0.01	0.005	0.01
Silicon	0.005	0.005	0.005	0.005
Tungsten	0.03	0.05	0.03	0.05
Nickel	0.005	0.005	0.005	0.005
Molybdenum	0.01	0.1	0.1	0.05
Hafnium	0.02	0.02	0.02	0.02
When Specified
Boron	0.0002	-	0.0002	-
Aluminium	0.002	0.005	0.002	0.005
Beryllium	0.005	-	0.005	-
Chromium	0.002	-	0.002	-
Cobalt	0.002	-	0.002	-

ASTM B 391 covers unalloyed and alloyed niobium ingots prepared by vacuum- or plasma-arc melting or electronbeam melting to produce consolidated metal for  processing to various mill shapes.
(NOTE 1—Committee B10 has adopted “niobium” as the designation for Element No. 41, formerly named “columbium.” )
ASTM B 392 covers four grades of wrought niobium and niobium alloy bar, niobium rod, niobium alloy bar, niobium wire, niobium alloy wire.
ASTM B 393 covers five grades of wrought niobium and niobium alloy strip, niobium sheet, niobium alloy sheet, niobium plate, niobium alloy plate.
R04200-Type 1—Reactor grade unalloyed niobium;
R04210-Type 2—Commercial grade unalloyed niobium;
R04251-Type 3—Reactor grade niobium alloy containing 1 % zirconium;
R04261-Type 4—Commercial grade niobium alloy containing 1 % zirconium;
R0xxxx-Type 5—RRR grade pure niobium.  (This grade of niobium is used in superconducting applications that require the ultra high purity. Because of the high purity the product is conducive to very large grains that can adversely affect formability. It is not recommended for other applications).

ASTM B 394 covers wrought niobium and niobium alloy seamless tube, niobium tube, niobium alloy welded tube, niobium welded tube, niobium seamless tube.

The materials covered by this specification are :
R04200-Type 1—Reactor grade unalloyed niobium;
R04210-Type 2—Commercial grade unalloyed niobium;
R04251-Type 3—Reactor grade niobium alloy containing 1 % zirconium;
R04261-Type 4—Commercial grade niobium alloy containing 1 % zirconium.