The manipulation of materials, and to some extent also their systematic classification, form an integral part of the skills and culture of all societies. Yet it took long for proper sciences (e.g., metallurgy, glass technology, polymer chemistry or solid-state physics) to develop out of many processing procedures, tapping the accumulated knowledge about specific material characteristics. In the late 20th century an overarching science of workable materials emerged: materials science. This concept and term originated from major boosts in materials research during WWII and the Cold War, first financed by the U.S. Department of Defense and the Advanced Research Project Agency (ARPA). The COSMAT-Report from 1974, written by the American Presidential Science Advisory Committee's ,,Committee on the Survey of Materials Science and Engineering'' four years after its inception, and subsequent reports heralded in the second institutionalization phase of materials science in the USA and with some delay also elsewhere. As the field continued to expand, the demand grew from within in the late 1990s for disciplinary status.This article sorts these claims from the various camps (by solid state physicists vs. chemists vs. engineers) and sets them in the context of unfolding institutional change. The developments within the German-speaking realm, thus far unduly neglected in these debates, are added. I close with a systematic discussion of eight indicator arguments for or against a convergence of this complex field of research into a single coherent discipline. Against Bensaude-Vincent's (2001: 242) thesis that materials science still is an ''aggregation of fragments of knowledge'', I argue that by 2010 materials science did indeed achieve disciplinary status in a historically rare and enduring process of discipline formation through ''emergence by integration'' rather than by differentiation.