Germany is widely regarded as a model case of social partnership, or corporatism, or, according to the theoretical typology of the school of “Varieties of Capitalism”, as a coordinated market economy. Great Britain, on the other hand, is seen as a perfect example of a voluntaristic form of industrial relations. This essay questions these assumptions by comparing the German metal union Industriegewerkschaft Metall (IGM) to its British counterpart, the British Amalgamated Engineering Union (AEU). From industrialization to the present the metal industry played a leading role in the economy and both unions were the largest in their industry. They faced the same global challenges, at times leading to almost identical responses. While some studies identify distinct national traditions of corporatism or voluntarism way before 1918, the author argues that a definitive bifurcation into two systems of industrial relations happened much later, namely in the period between 1973 and 1979. At this turning point, British unions lost any hope for a corporatist arrangement, while German corporatism survived as “defensive social partnership” leaving less room for manoeuvre for the trade union side.