https://www.nickelalloytubes.com/products/astm-b338-asme-sb338-titanium-alloy-steel-pipe-tube/ ASTM B338/ ASME SB338 Titanium Tube (Ti Tube) has a superior strength-to-weight ratio and corrosion resistance is one of the common titanium products. We generally divide ASTM 338/ ASME SB338 Titanium tubes into two types, one is called the seamless titanium tube, and the other is called the welded titanium tube.