Tin Broadsword

Tin is the copper substitute and the swap is close to invisible in play. This is a first-day sword, something to build out of the surface ore so you are not still poking slimes with the starter blade.

The moment demonite or crimtane turns up, or a chest hands you anything with reach, this is finished. Skip the temptation to climb every ore tier on the way up. The bars do more for you in a pickaxe than in a marginally sharper sword.