A great variety of tuning forks survive in collections around the world, from departments of physics, phonetics, and psychology, to medical settings, conservatories, and museum collections. Their ubiquity speaks to their iconic status, while their diversity points to the multifaceted cultures of materiality that shaped and formed around these objects. This chapter traces the complex supply chains of nineteenth-century tuning forks from the gathering and processing of iron and crucible steel to their sites of manufacturing and various uses. By probing further into these nodes of supply and use, we uncover a chain of values and contingencies that reveal the interdependencies between extracting, commercial, scientific, and artistic practices of the past.