<p>Industrial decarbonization is increasingly constrained by technology choice, availability and quality of resources. Metal scrap can lower emissions in metal production as it can substitute for primary iron and other metal routes with substantially lower energy demand, especially when paired with low-carbon electricity. Yet the climate benefit of scrap-based production is dependent on reliable end-of-life capture, effective sorting and pre-processing, impurity control during melting and refining, and governance arrangements that treat scrap as a strategic industrial input rather than residual waste. While these challenges apply across metal recycling systems, this study focuses primarily on the iron and steel sector, which represents the largest and most structurally developed global scrap market. This study conducts a targeted literature review combined with international benchmarking to examine the metal scrap value chain and its role in supporting green manufacturing and industrial decarbonization. Scrap system performance and policy configurations are compared across five major steel economies to identify transferable lessons. The analysis shows that scrap availability alone does not guarantee high utilization; rather, furnace structure, electricity conditions, market organization, and quality standards jointly determine scrap absorption. Advanced systems achieve higher effective recycling through formalized collection, extended producer responsibility, standardized grading, and investment in sensor-based sorting and dismantling practices, while fragmented and informal-heavy systems face persistent losses and quality variability. Although the benchmarking focuses on iron and steel systems, the findings highlight systemic challenges—such as collection efficiency, material purity management, and governance coordination—that are broadly relevant to other metal recycling systems, including non-ferrous metals.</p>