Prior to the mid-1920s, Söderberg & Haak had almost exclusively Swedish suppliers. As the company began to import products on a large scale, foreign manufacturers were able to offer them advantageous prices. In turn, several Swedish mills had started building up their own distribution channels alongside the wholesalers. As the wholesalers increased their imports, Swedish manufacturers became ever more eager to bypass the Swedish wholesalers. The first larger, regular import operation for Söderberg & Haak was initiated in 1926 and involved pipes from the French-Belgian-Saarlandish company Comptoir FBT.
Fagersta had long been the largest supplier to Söderberg & Haak. A major mill consolidation occurred in 1927, out of which the Fagersta Group was formed. Around 1930, Fagersta began to build out its own sales organisation. In 1934, Söderberg & Haak also lost the agency for Domnarfvets Jernverk.
Söderberg & Haak began importing tractors from the American firm Oliver in 1936, and during subsequent years accounted for over one-third of tractor deliveries to Swedish agriculture.