By examining the history of the Ahvāz pipe mill in the 1960s and 1970s, this article investigates the manner in which competing understandings of Iran's modernizing trajectory among Pahlavi officials were bound up with the material aspects of steel, such as weight, volume, and form. The mill was built to provide pipe for the First Iran Gas Trunkline, a sprawling system intended to gather, refine, and transport natural gas to Iranian cities and the Soviet Caucasus. Officials overseeing the project debated whether the mill's design should prioritize serving the pipeline project or, more ambitiously, establish a new pipe rolling industry able to serve domestic and regional markets. Argued in this article is the significance of attending to infrastructure and materiality in understanding Iran's twentieth-century history of developmentalism.