Iron Hammer

Hammers cover the jobs a pickaxe cannot: knocking out background walls, cycling a placed block through its slopes and half-block shapes, and clearing the wooden platforms and beams that clutter old structures. The iron one is the first hammer most players make, and it handles everything structural in pre-Hardmode. It will not touch a Demon Altar; that needs the hammer the Wall of Flesh drops.

Journey Mode characters start with one in the bag, so if you are playing there you can skip the forge entirely.

Speed wins over power here. You will swing a hammer hundreds of times across a build session and almost never at an enemy, so take the reforge that shortens the swing and ignore the damage ones. Paying for a combat modifier on a hammer is money you should have spent on a pickaxe.