ASTM RO5200 RO5255 RO5252 Bright Smooth Tantalum Bar for Electronic Industry Tantalum bar,Tantalum- tungsten alloy bar,Tantalum-niobium.Material:RO5200,TaNb3 RO5252(Ta2.5W), RO5255(Ta10W).high temperature using parts,teaction containers,etc.Tantalum bars are widely used for high temperature using parts,teaction containers,etc.