The aim of this paper is to examine the evolution of the market machinery industry in Brazil and Sao Paulo between 1920 and 1960, with the object study of two major companies for consolidation in this industry country, Dedini and Romi. The choice of these companies due to the existence of specific studies and historical collections with economic and financial documents. Will highlight the similarities and differences in the performance of these two companies in context of market developments machinery industry. Companies emerged as a small workshop in the first decades of the twentieth century, evolved with the specific market where it operated with great changes in the 1920 and 1930 and signed in the sector after a decade 1940. In the 1960's were the main companies in the sector in which they operated.