Titanium Skeleton Key

Overview
The Titanium Skeleton Key can be created and used by Blacksmiths to open locked doors or chests requiring up to 400 Lockpicking skill.

This includes all Eastern Kingdoms, Kalimdor, Outland, and Northrend chests, and all locked dungeon doors in Azeroth and Outland.

Source
This item is crafted with Blacksmithing (430).