Nambu Tekki is a collective term for traditional pure iron casting products from the Nambu region of Iwate Prefecture. Ironware originated in Oshu during the late Heian Period (about 930 years ago), then emerged in Morioka during the mid-17th century. Nambu Tekki pieces are made by pouring pure iron into a mold made of sand or clay, then steaming the work over a coal fire to create a rust-resistant oxide film. The entire process may take a month or more from start to finish.