Unior has been building on its tradition of quality since 1919. In 1950 new capacities were acquired, which represented the basis for the development of two new manufacturing programmes: hand tools and drop forgings, which had begun to increasingly assert themselves in the production of cars, tractors, motorcycles, bicycles, internal combustion engines and similar machines. In 1970 this factory, with its new vision for development, acquired a new name: Unior, Factory of Forged Tools Zreče. Its new vision stems from the already-established co-operative ventures with European companies, especially West German ones.

In the 1980s Unior asserted itself as an important European automotive industry partner, as one of the major European manufacturers of light forgings and also one of the largest European manufacturers of connecting rods for gasoline engines, which puts it among the major suppliers for companies like VW, BMW and others. The first steps in this field were taken with a Renault Group contract, which later developed into today's joint-venture plant for the manufacture of forgings, erected at Zreče, with the parallel development of velocity joints and machine building, at first intended particularly for Unior's own needs. Today, the forging parts programme is globally oriented, building on expanding its market share together with associated companies all over the world.