Cast iron objects recovered primarily in eastern Mongolia, spanning the Xiongnu through the Early Historic periods (ca. 3rd BC–AD 17th century), were examined for their radiocarbon (14C) concentration and microstructure. Most of the samples examined were found to have originated from charcoal-based smelting with a few exceptions that were made using a mineral coal-based technique. A comparison of 14C dates with dates derived from artifact typology allowed the charcoal-smelted objects to be classified into two groups, based on whether the radiometric and typological periodization are in agreement or not. In addition, those with differing 14C and typological dates can be divided into two subgroups with and without evidence for a melt treatment applied after original casting. These conflicting dating results are confusing and would seem to provoke skepticism about the use of 14C measurements for dating iron artifacts. We demonstrate however that 14C analysis, when combined with metallographic examination and other lines of chronological evidence, can clarify the history of a given iron object and its multiple users, often separated in time by more than a millennium.