As this is a story achievement be aware of spoilers.
*** Spoiler - click to reveal ***This is unlocked at the end of the first official quest. You have a number of objectives to be solved, a few can be done in multiple ways. For example I snuck into the drunk deadbeats house used to knock him out, then stole back fathers axe, nails and hammer.
Just make sure to leave the ale til last, otherwise you'll do what I did and it will get warm.
Once you've successfully brought all the items to father, a long cutscene will play where you and him finish forging lord Radzigs sword. After this cutscene the achievement should pop.
Let's keep cheevin' together!