This study aims to provide basic data for actual heritage conservation areas by suggesting the reuse method of materials from wooden historic buildings. This research may contribute to an increase in the utilization of materials for stabilizing the structure of wooden historic buildings. The data were collected by applying heating, tapping, and heat treatment based on the pattern and extent of the damage of iron nails acquired from wooden historic buildings. To make a comparison before and after processing, morphological characteristics and physical properties were measured using a metallurgical analysis. According to these data, we can infer that the possibility of reuse of historic iron materials could be raised in the restoration process of historic buildings such as existing building components and roof tiles. If the research is to move forward, authenticity will be fostered in architectural heritage conservation.