After World War II, the company relocated to its present headquarters at Nauheim, Germany. The Julius Keilwerth company became one of the largest saxophone manufacturers in Europe by the start of WWII, with approximately 150 workers. They primarily manufactured saxophones for Adler and FX Hüller. After this apprenticeship, Julius Keilwerth and his brother, Max, established a workshop in their home around 1925 or 1926.
Julius Keilwerth first apprenticed for the Kohlert company in Graslitz, Czechoslovakia.
