The new Ti parts are just beautiful. I wonder how they were made and polished, if Ti is so very hard?
Similar to steel. Ti is extremely hard
for a lightweight metal. It is much harder than aluminum, and even mild steel, but not as hard as the hardest steels.
Titanium is neither as strong as the strongest steels, nor nearly as light as aluminum. What makes Ti so desirable is that its strength-to-weight ratio is superior to both of those, and the best of all metals. It is also far more corrosion resistant than both steel and aluminum (I don't know how its corrosion resistance compares to the various stainless steel alloys).
Also, of course, just like steel and aluminum, Ti can be (and usually is) alloyed with other metals, so "Titanium" is not always exactly the same thing with exactly the same properties. Like steel, most of the alloys can be hardened with heat treating, so they can be milled and worked while in their softer state, and then heat treated to the desired hardness.