The Drax (known as the Hamdrax before v1.2) is a tool which is crafted from Hallowed Bars and one each of the souls dropped by the mechanical bosses. This hybrid is the second best drill, but is not the strongest axe in the game (this slot is occupied by The Axe). Like all drills, it cannot be reforged with any prefix that increases size (which includes "Legendary"), leaving its best possible prefix as "Godly". It is a great tool for mining and cutting down trees. It is the second best combination of a Pickaxe and an Axe, only being surpassed by the Picksaw and Laser Drill, which has 210% Pickaxe power and 125% Axe power and a faster use time.
Much like the Hamaxe, the Drax's name is a portmanteau of the tools whose purposes it serves: Drill and Axe. "Dr" as in Drill, "Ax" as in Axe.
Before 1.2, the Drax was called Hamdrax, a combination of hammer, drill and axe. The hammer part was removed due to half slabs coming out.