Material :  Tantalum gasket
Purity    :  99.95%min
Condition: temper annealed
Specs   :   according to ASTM B708 - 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%)
Size available:  customize to your special request or tailor to your drawings.
Typical size :
43.7mm OD x 28.6mm ID x 3.5mm thick
51.6mm OD x 36.5mm ID x 3.5mm thick
92.9mm OD x 69.8mm ID x 3.5mm thick
127.8mm OD x 98.4mm ID x 3.5mm thick
153mm OD x  138 mm ID  x 4.1mm thick
158mm OD x 123.8mm ID x 3.5mm thick

We can tailor the sizes upon request.

Standard Specification ASTM B 708 -05 for Tantalum Ribbon, Tantalum Alloy Ribbon, Tantalum Strip, Tantalum Alloy Strip, Tantalum Foil, Tantalum Alloy Foil, Tantalum Sheet, Tantalum Alloy Sheet, Tantalum Plate, Tantalum Alloy Plate.
This specification covers unalloyed and alloyed Tantalum Ribbon, Tantalum Alloy Ribbon, Tantalum Strip, Tantalum Alloy Strip, Tantalum Foil, Tantalum Alloy Foil, Tantalum Sheet, Tantalum Alloy Sheet, Tantalum Plate, Tantalum Alloy Plate as follows:
1. ASTM B 708 -05 UNS R05200, unalloyed tantalum, electron-beam furnace or vacuum-arc melt, or both.
2. ASTM B 708 -05 UNS R05400, unalloyed tantalum, powder-metallurgy consolidation.
3. ASTM B 708 -05 UNS R05255, tantalum alloy, 90% tantalum 10% tungsten, electron-beam furnace or vacuum-arc melt, or both.
4. ASTM B 708 -05 UNS R05252, tantalum alloy, 97.5% tantalum 2.5% tungsten, electron-beam furnace or vacuum-arc melt, or both.
5. ASTM B 708 -05 UNS R05240, tantalum alloy, 60% tantalum 40% columbium, electron-beam furnace or vacuum-arc melt.