Following on from our previous research on recyclable material collectors in Egypt, Turkey, and on “scrap metal dealers” in the Paris suburbs, this portfolio is based on interviews conducted in Istanbul between 2014 and 2024. It focuses on the continuum that links informal recyclers to formal wholesalers, particularly those of scrap metal, via intermediaries who contribute to these market circulations through their sorting and dismantling work. The portfolio highlights a historical, economic and social cycle: in search of “iron workers”, we met workshop owners belonging to the Roma community of Istanbul whose know-how in metal trades is ancestral. These workshops source semi-finished metal materials derived from recycling, purchased from small foundries, which are supplied by scrap metal wholesalers. The latter themselves rely on the informal urban metal recovery sector. The workshops in turn generate offcuts which then re-enter the recycling loop. These commercial flows of metal recycling operate through social and professional networks that enabled us to move from one actor to another: the wholesalers—often former toplayıcılar (waste pickers)—are the essential link in the informal-formal continuum of these scrap metal circulations.