Blacksmithing is the skill or proficiency of forging bars of metal and other reagents from miners and working them into nicely-crafted weapons and armor which are primarily used in fighting. Due to this, the Blacksmith profession very suits the warrior and Paladin classes that can initially wear mail armor they stand to profit many from having the capability to forge their own weapons and armor.
Blacksmithing is of great use in a systematic World of Warcraft economy system, for instance, people who practice this profession called Blacksmiths have the ability to create a wide diversity of much-needed items for other professions like the Enchanter’s Rod for the occupation of enchanting. By using special sharpening stones, they also can hugely upgrade the weapons of every character class in order to cause much more of their massive destructive damage. Blacksmithing might not be a hugely profitable World of Warcraft profession compared to any other profession. This is just because of the fact the finished products are frequently sold for considerably less than the cost of their primary raw materials.
However, Blacksmithing is a skill that remains so useful and much-needed for a player to learn because there are so many unique items that can only be forged by Blacksmiths in WoW. Like the Alchemy professsion, Blacksmithing is rated as a Primary Service Profession so it counts toward your restriction of two Primary professions. The most obvious selection of Profession to best couple with Blacksmithing is mining owing to the ever-growing demand for ore and gems.