Specs : according to ASTM B521 -98 R05200.
Chemical composition : 
            O         0.0150 %max
            C         0.0100 %max
            N         0.0100 %max
            H         0.0015 %max
            Fe        0.0100%max
            Ni         0.0100%max
            Si         0.0050 %max
            Ti         0.0100 %max
            Mo       0.0200 %max
            W        0.0500 %max
            Nb       0.1000 %max
            Ta balance (typically 99.92%)
Physical & Mechanical property :
            Tensile strength 207 MPa min.
            Yield strength    138 MPa min.
            Elongation         25%min 
Size available :
0.03937" to 6.30" Outer Diameter x .007874" to 0.03937" Wall x length up to 29.5 ft, or
10 up to 160mm Outer Diameter x 0.2 up to 10mm Wall Thickness x Length up to 9000 mm max.
Typical size :
(OD=Outside Diameter or Outer Diameter, ID=Inside Diameter or Inner Diameter, WT=Wall Thickness, LG=Length)
10mm OD x 9mm ID x 0.50mm WTx 1100mm Length(.3937"=OD);
10mm OD x 8.4mm ID x0.80mm WTx 1000mm Length(.3937"=OD);
10mm OD x 8.0mm ID x1.00mm WTx 800mm Length(.3937"=OD);
10mm OD x 1.00mm WTx 1016mm Length(.3937"=OD);
10mm OD x 6.0mm ID x 2.00mm WTx 600mm Length(.3937"=OD);

12mm OD x 11.24mm ID x 0.38mm WTx 1100mm Length(.4724"=OD);
12mm OD x 10mm ID x 0.5mm WTx 150mm Length;
12mm OD x 10.5mm ID x 0.75mm WTx 150mm Length;
12mm OD x 10mm ID x 1.0mm WTx 1000mm Length;
12mm OD x 2.0mm WTx 1000mm Length;

12.7mm OD x 11.7mm ID x 0.5mm WT(1/2"=OD, 0.02"=WT);
12.7mm OD x 11.68mm ID x 0.51mm WTx 1828mm LG(1/2"=OD, 0.46"=ID, 0.02"=WT, 6ft=LG);
12.7mm OD x 0.7938mm WTx 3048mm LG(1/2"=OD, 1/32"=WT, 10ft=LG);
12.7mm OD x 10.7mm ID x1.00mm WTx 1016mm Length(1/2"=OD, 40"=LG);
12.7mm OD x 10.3mm ID x1.20mm WTx 1000mm Length(1/2"=OD, 39.37"=LG);

13mm OD x 0.40mm WTx 1000mm Length;
14mm OD x 0.40mm WTx 600mm Length;
14mm OD x 13mm ID x 0.50mm WTx 2000mm Length;
14mm OD x 13mm ID x 0.50mm WTx 6000mm Length;
14mm OD x 10mm ID x 2.00mm WTx 2300mm Length;
14mm OD x 2.5mm WT;

15mm OD x 14.20mm ID x 0.4mm WTx 1000mm Length;
15mm OD x 0.50mm WTx 200mm Length;
15.9mm OD x 0.50mm WTx 145mm Length;
16mm OD x 0.40mm WTx 1600mm Length;
16mm OD x 0.50mm WTx 3000mm Length;
17mm OD x 1.00mm WTx 400mm Length;
18mm OD x 16mm ID x1.00mm WTx 1100mm Length;
18mm OD x 15mm ID x1.50mm WTx 105mm Length;
18mm OD x 13mm ID x2.50mm WTx 105mm Length;

19.0mm OD x 17mm ID x 1.00mm WTx 1100mm Length;
19.05mm OD x 0.381mm WT (3/4"=OD, 0.015"=WT);
19.05mm OD x 0.50mm WT x 3000mm LG (3/4"=OD, 0.02"=WT);
19.05mm OD x 0.60mm WT x 3010mm LG (3/4"=OD);
19.05mm OD x 16.56mm ID x 1.24mm WT(3/4"=OD, 0.049"=WT);
19.05mm OD x 1.65mm WT x 900mm LG (3/4"=OD);
19.5mm OD x 18.7mm ID x 0.4mm WT x 1879mm LG;

19.05mm OD x 18.03mm ID x 0.508mm WT x 9000mm LG;

20mm OD x 0.9mm WTx 1000mm Length;
21.3mm OD x 17.3mm ID x 2mm WT x 2000mm LG;
24mm OD x 1mm WTx 1100mm Length;
25mm OD x 2mm WTx 1000mm Length;
25mm OD x 2mm WTx 6000mm Length;
25.4mm OD x 24.6mm ID x 0.4mm WTx 3260mm Length(1"=OD);
25.4mm OD x 24.3mm ID x 0.55mm WT(1"=OD);
25.5mm OD x 24.7mm ID x 0.4mm WT x 1000mm LG (1"=OD);
26.4mm OD x 0.5mm WTx 1000mm Length;

30mm OD x 20mm ID x 5mm WT x 2600mm LG;
31.75mm OD x 0.381mm WT x 6000mm LG (1-1/4"=OD, 0.015"=WT);
32mm OD x 0.4mm WT x 5120mm LG;
32mm OD x 0.7mm WT x 6000mm LG;
33.7mm OD x 2mm WT x 6000mm LG;
38mm OD x 2.5mm WT x 200mm LG;
38mm OD x 1.30mm WTx 2500mm Length;
38.10mm OD x 0.6096mm WT x 2438.4mm LG(1-1/2"=OD, 0.024"=WT, 96"=LG);

60.3MM OD x 56.30MM ID x 2MM WTX 914.40MM LG
120 mm OD x 1.6mm Wall x 2540mm Length ( 25.20 kg/pc) 

Outer diameter(OD): 10.0~108mm, tyipically
OD 12.7mm(1/2")
OD 15.88mm(5/8")
OD 19.05mm(3/4")
OD 25.4mm(1")
OD 38.1mm(1.5")
OD 50.8mm(2")
OD 63.5mm(2.5")
OD 76.2mm(3")
OD 88.9mm(3.5")

Wall thickness(WT): 0.51~10mm, such as
WT 0.51mm(BWG 25)
WT 0.56mm(BWG 24)
WT 0.63mm(BWG 23)
WT 0.71mm(BWG 22)
WT 0.81mm(BWG 21)
WT 0.89mm(BWG 20)
WT 1.07mm(BWG 19)
WT 1.24mm(BWG 18)
Length : 304.8mm to 6200mm ( 1ft to 20.34 ft)

Trade name: tantalum tube, tantalum tubes, tantalum tubing, tantalum tubings, tantalium tube, tantalium tubes, tantal tube, tantal tubes, tantal pipe, tantal pipes, tantal tubing, tantal tubings, tantalum ampoule, tantalum ampule, tantalum sheath, tantalum sleeve, tantalum shell, tantalum protect tubing, ta tube, ta tubing, tantalum heat exchanger system tube, tantalum hollow bar, tantalum hollow bars, tantalum hollow cylinder, tantalum hollow cylinders, etc., etc.,

Standard Specification ASTM B 521 -98 for Tantalum Tube + Tantalum Alloy Tube Seamless and Welded.This specification covers tantalum and tantalum alloy seamless and welded tubes of the following grades:
1. ASTM B 521 -98 UNS R05200, unalloyed tantalum, vacuum melt;
2. ASTM B 521 -98 UNS R05200, unalloyed tantalum, powder-metallugry consolidation;
3. ASTM B 521 -98 UNS R05255, tantalum alloy, 90% tantalum 10% tungsten alloy, vacuum melted;
4. ASTM B 521 -98 UNS R05252, tantalum alloy, 97.5% tantalum 2.5% tungsten alloy, vacuum melted;
5. ASTM B 521 -98 UNS R05240, tantalum alloy, 60% tantalum 40% columbium, electron-beam furnace or vacuum-arc melt, or both.