What "amazing mechanical properties" do the swords possess?
The steel is very hard and takes a fine edge without being brittle.
Iron by itself is hard, but brittle, and weapons made from it can shatter easily, which is not a good thing.
Steel, which is iron mixed with other materials, is just as hard, but is flexible and not so easy to shatter. Problem is getting the mix and pattern right, because poorly made steel weapons have breakage problems as well.
Damascus steel for its time was exceptionally good material to make weapons from and weaponry made from it tended not to break. This may not be remarkable today, but for its time that was amazing.
I remember my 7th grade history teacher telling us about Damascus steel. He said that it was extremely flexible yet hard at the same time and they didn't know how it was done. How interesting.