The Dwarven Swordsmiths are characters from The Legend of Zelda: A Link to the Past.
A Link to the PastKakariko Village and work as swordsmiths for a living. They discourage people from attempting to temper a sword on their own seeing as they are the only professionals around. When Link first goes to meet them, he only finds one of the swordsmiths at the house, tinkering away at a piece of metal. He tells Link that he can't temper his sword at the moment because his partner has not returned.
After Link obtains the Titan's Mitt from Thieves' Town dungeon and heads to the southern part of the Village of Outcasts, he will find a strange frog who is trapped behind some black stones. Using the Mitt, Link removes the stones that are in the way in order to set him free. After Link talks to him, he finds out that the frog is the missing swordsmith. The frog then requests that Link take him back home.
Using the Magic Mirror, Link transports the two back to the Light World and takes the other swordsmith (who is now back to normal) to his home. Once there, the two swordsmiths are overjoyed to have found each other and as a reward they offer to temper Link's sword the next time he comes by. When Link comes by again, the two are ready to temper his sword. They give him a big discount and let him pay only 10 rupees as a thank you and with the Hero's permission they begin their work. Once Link returns once more he finds that the sword has been tempered in a red and much more powerful sword than he had before.
During the Ending, the swordsmiths are seen working in their Smithy.