From 1d4chan

Blacksmith is a Spheres of Might class focused on not just crafting items but also wrecking shit, getting a nice pile of bonus damage whenever they sunder or otherwise attack an item or construct as well as adding other penalties upon sundering. They can also sunder natural weapons and armor to penalize AC and attacks, so fighting regular monsters doesn't invalidate their entire playstyle.

Normally sundering is considered terrible since you're destroying valuable loot like an idiot, but blacksmiths have the ability to quickly repair broken or even destroyed items. Of course, this does mean that if the enemy has a blacksmith and you don't, your more equipment-dependent members will be shit out of luck.

In addition to breaking everything, blacksmiths also get to create, repair and even reforge magical equipment, restoring destroyed magic swords or turning them into equally magic guns or the like. When they're not doing that, with 8 hours of rest they can perform armor maintenance on themselves and their allies, giving save bonuses, lower ACPs and so on. One archetype replaces armor maintenance with cooking, which is much faster but likely to pause the game as the players order yet another pizza and/or argue over the existence of potatoes in the game. Another makes them into ghetto Technicians, giving access to some technical insights and improvements from that class.

Thanks to having a d10 hit die, Con as their practitioner modifier and good Fortitude and Will saves, Blacksmiths are some of the toughest bastards on the block even if they decide to go ranged.

The Classes of Pathfinder 1st Edition
Core Classes: Barbarian - Bard - Cleric - Druid - Fighter - Monk
Paladin - Ranger - Rogue - Sorcerer - Wizard
Player's Guide:
Alchemist - Antipaladin - Cavalier
Inquisitor - Oracle - Summoner - Witch
Class Guide:
Arcanist - Bloodrager - Brawler - Hunter - Investigator
Shaman - Skald - Slayer - Swashbuckler - Warpriest
Kineticist - Medium - Mesmerist
Occultist - Psychic - Spiritualist
Ultimate X: Gunslinger - Magus - Ninja - Samurai - Shifter - Vigilante
The Third Party Classes of Pathfinder
Psionics: Psion - Psychic Warrior - Soulknife - Wilder
Aegis - Cryptic - Dread - Marksman - Tactican - Vitalist
Path of War: Stalker - Warder - Warlord - Harbinger - Mystic - Zealot
Akashic Mysteries: Daevic - Eclipse - Guru - Nexus - Radiant - Rajah - Stormbound - Vizier - Zodiac
Spheres of Power: Armorist - Elementalist - Eliciter - Fey Adept - Hedgewitch - Incanter
Mageknight - Shifter - Soul Weaver - Symbiat - Thaumaturge - Wraith
Spheres of Might: Armiger - Blacksmith - Commander - Conscript
Savant - Scholar - Sentinel - Striker - Technician
Champions of the Spheres: Prodigy - Sage - Troubadour - Dragoon - Mountebank - Necros - Reaper - Warden - Crimson Dancer
Pact Magic: Pactmaker (formerly known as Medium)