As the first technology to be ripe for production, the acid Bessemer process dominated the expansion phase of the new steel industry, which was consequently wholly characterised by the process's metallurgical particularities. A new metal had been created in Bessemer steel, one capable of filling the gaps between puddled iron and crucible steel and which robbed both of a good part of their market. It could be cast in any moulds and, unlike the blooms produced in puddling furnaces, in sizes appropriate to the end product, resulting in less wastage. Thus was rendered superfluous the permanently critical practice of welding several pieces together, which the rails manufacturers viewed as the greatest disadvantage of puddled rails and the reason for their lower quality.

In terms of price, Bessemer's steel was far closer to puddled iron than to crucible steel. However, initial ambitious hopes that it would entirely replace crucible steel were not fulfilled, since it never quite achieved the same quality. In fact, the first people to adopt the new process at the start of the 1860s, John Brown in Sheffield and Alfred Krupp in Essen, did still think that they had found a cheaper alternative to their own crucible steel production. Indeed, Krupp, who had been smelting steel made in puddling furnaces down again in crucibles since the 1850s, was already concerned that the new process would render his entire works obsolete. John Brown was about to build a big new works according to Krupp's model when he learnt about Bessemer's process. He came to the same conclusion as Krupp, dropped his plans for a combined puddling and crucible steelworks and went straight over to manufacturing Bessemer steel.