Mary, Grade 1 and 2 can be surgically certified. They are
commercially pure. The amount of oxygen, nitrogen and other elements
determine the working characteristics. Here we are talking about the
elements in parts per million. No titanium is 100% pure.
Grade #5, often called 6/4, is 6% aluminum and 4% vanadium. There
are dozens of other special purpose alloys.
The above 3 grades can be hot forged. At just over 1,600 F the
metals phase change and hot forge well. There is a lot of clean up
Grade #1 is also cold forgeable, and work hardens slowly.
Reactive Metals Studio, Inc