I am no sure what the 4v stands for and don't take my word for it, but
if the titanium has a 3 rather than a 6 the strenth is 90,000 (6 is
160,000 4130 is 120,000.). I priced a 1 inch tube 60 inches long the
price was $550.00. There is a web site that sells cut ends much cheaper
(Titanium Joe   www. titaniumjoe.com) about 1/5 the price.

  Welding Stanless requires an argon gas purge both side. The difference
with titanium is the gas coverage for titanium on the out side needs to
be larger so a standard tig cup will not work. You need a traliing purge
as well or in a box. The oxgen has to be below .1 % and should be 0.

Harry