Board Thread:Lore Discussion/@comment-12481512-20130717104617/@comment-11344160-20130718030905

You can make bows out of a many different metals, so I don't think its any more flexible than other metals.

Most likely it is the Dwemer version of steel - the result of processing one type of ore with another element/chemical. That process was lost with the Dwarves, along with a lot of other stuff.