In the 1980s there was a surge of trade union power on a scale not previously experienced in South Africa. The National Union of Metalworkers of South Africa (Numsa) was a highly prominent and innovative union in this assertion of muscle and one of Cosatu's most radical affiliates, and its story is one of astonishing achievements as its activities built workers' rights and deeply eroded the apartheid state. Metal that will not bend – a translation of the union's motto Insimbi ayigobi – tells that story by revisiting the formation of the powerful modern day union movement. The trade union movement kept the internal struggle alive in the late 1980s when community organisations in the United Democratic Front (UDF) had been smashed. Many books have been published on the ANCs struggle for liberation. However, this critical aspect of internal mass mobilisation, which put pressure on the apartheid state through huge stayaways and which relied almost entirely on the organisation of Cosatu and its strong affiliates, has generally not been adequately explored. Metal that will not bend traces the themes of power, independence and workers’ control as they were practiced by Numsa. A number of small metal organisations with at times antagonistic organisational and political strategies were built in different ways and with different attitudes to the exiled liberation movements in the early 1980s. They eventually unified into one powerful organisation. Kally Forrest describes how workers' struggles built this power, and she scrutinises the strategies used in the late 1980s, such as innovative bargaining strategies, to significantly improve the conditions of impoverished workers. The book then progresses to examine how Numsa used its power in an attempt to insert a workers’ perspective into the political transition of the early 1990s. It explores the obstacles the union faced, such as the violence that erupted across the country, and its commonality and divergence from the politics of the liberation movements (chiefly the ANC).