Scioto Furnace is an unincorporated community in western Bloom Township, Scioto County, Ohio, United States. Although it is unincorporated, it has a post office, with the ZIP code of 45677. It lies along State Route 140.HistoryA post office called Scioto Furnace has been in operation since 1862. The community's namesake Scioto Furnace was a blast furnace which was in operation from 1828 until 1892.