The Titanium Pickaxe is a Hardmodepickaxe and the pickaxe alternative to the Titanium Drill, having a slower mining speed but longer range and benefiting from mining speed bonuses. Its alternate ore counterpart, the Adamantite Pickaxe, is slightly weaker than the Titanium Pickaxe.
Early into Hardmode, it is usually preferable to save Titanium for armor and weapons, as the Titanium Pickaxe does not allow mining any new blocks that the Mythril and Orichalcum pickaxes and drills would not mine.
However, the Titanium Pickaxe is the first pickaxe that can reach a mining speed of 1 (max) with capped mining speed (70%) and a speed modifier. The Adamantite Pickaxe is slower, thus unable to achieve this.