Users are able to craft many different kinds of items to sheer perfection. They are able to forge the strongest of weapons, the toughest of armors, the greatest of statues, the most powerful of items, and much more. Some are able to create with nothing but the material around them, and in very short notice.
Tobho Mott (A Song of Fire and Ice/Game of Thrones) is a master armorer and blacksmith in King's Landing. According to himself, he is the only armorer in the city who can add tint to the metals in a suit of armor without using paint, and can reforge swords from existing Valyrian steel, something only the greatest weaponsmiths can do.
Ōetsu Nimaiya (Bleach) is a spiritual master swordsmith who invented the Zanpakuto particularly Asauchi.
Wendy Rockbell (Full Metal Alchemist) is an exceptionally gifted and passionate mechanic possessing extensive expertise in crafting and overhauling automail prostheses.
Tōtōsai (InuYasha) is the demonic sword smith who forged the Tessaiga and Tenseiga from the fangs of his old friend, the Inu no Taishō. He also has the ability to communicate with the swords.
The Tessaiga (InuYasha) is the sword of destruction with the ability to kill 100 demons with one strike that was forged by Tōtōsai, and wielded by Inuyasha.
The Tenseiga (InuYasha) is the sword of life that is able to bring back 100 lives to life with one strike that was also forged by Tōtōsain and wielded by Sesshōmaru.
Kaijinbo (InuYasha) was an ex-apprentice of Tōtōsai who possessed great skills in forging demonic wepons, but infamous for crafting weapons housing great and sinister powers.
Tōkijin, (InuYasha) was a powerful demonic sword forged by Kaijinbō from the fangs of Goshinki. The sword's demonic power rivaled that of the Tessaiga and was even able to battle on par with other Daiyōkai.
The Naginata of Kenkon (InuYasha) was a powerfully destructive weapon forged from the souls of 222 demons by Kaijinbō on the order of Hoshiyomi. The weapon possessed incredible demonic power capable of opening the void between Heaven and Earth.
Hosenki (Inuyasha) has extraordinary skills in crafting powerful mystical gemstones such as the Black Pearl.
Tōshū (InuYasha) was a swordsmith who forgeed the formidable Dakki from the dragon scales of Ryūjin. Although he was just a human, he was able to make the demonic sword strong enough to steal Inuyasha's Tessaiga's demonic energy.
Muramasa (Ninja Gaiden series) is a legendary master weaponsmith, known for smithing some of the world's most powerful weapons. In addition to creating weapons ,Muramasa can also refine weapons, having the capability of making vast improvements to Ryu's arsenal of weaponry including the Dragon Sword.
The Kozuki Family (One Piece) are a clan of master stonemasons, they crafted the Poneglyphs, ancient steles which are indestructible.
Dwarves (Shinju no Nectar) are a race of master craftsmen with utmost skills in forging, stonemasonry and metallurgy.
Bismuths (Steven Universe) are capable builders and blacksmiths. Bismuth in particular was able to outfit and enhance all of the weapons of the Crystal Gems during the rebellion…
…such as Rose Quartz's sword, which can poof a Gem in a single swipe without shattering them…
…and was also capable of upgrading current weapons such as Garnet's guantlets with spiked brass knuckles…
...upgrading Pearl's spear into a trident…
…Amethyst's whip into a multi-tailed fail…
…the Breaking Point with the express purpose of targeting and destroying the gemstones of other Gems, permanently shattering them.
Aule (The Silmarillion) is the smith of the Ainur and the one responsible for crafting all the things that make up Arda/Middle-Earth, including the Sun and Moon.
Tatara (Valkyrie Crusade) the saint of smithing.
Enchanter (Valkyrie Crusade) is a craftswoman who creates magic items and ornaments and infuse things with magic.
Blacksmith (Valkyrie Crusade) is a master craftswoman.
Although he was poor fighter, Suzuki (Yu Yu Hakusho) was an incredible craftsman, having created the very tools and weapons that aided his Team Uraotogi's vicotries in the Dark Tournament...
...such as the Steaming Spheres that granted Kuro Momotaro three Beast Armors that made him immune to an already-exposed attack of an opponent and increased his strength...
...the Idunn Box, which regresses an opponent to an earlier stage of life...
...the Cape of No Return, which has the ability to manipulate space in order to send anyone caught in it to another location in the three worlds...
...the Trial Sword, which has the ability to absorb and enhance the energy of it's wielder, and the potion of the Fruit of the Previous Life, which has ability to revert the one who drinks it to an earlier point of their life.