... Gr3,Gr4,Gr5,GR7,GR9,GR11,GR12 etc2.standard:ASTM B/ASME SB861,337and 3383.specification:outer diameter:.4 ... grade 2 is widely used in the commerciallu pure Titanium.CP grade 3 is almost only used in the ... chemical properties.Alloy Gr7,add little palladium in cp Titanium and it has the most excellent corrosion-resistence Alloy ... quality and resonable price ,welcome any inquiries! metal tubes-Titanium tube