1920—1932: From Versuchsbau Hellmuth Hirth to Elektronmetall G.m.b.H., Stuttgart-Cannstatt (EC )
| 1920 | Hermann Mahle joins Versuchsbau Hellmuth Hirth |
| 1921 | First series production of light-alloy pistons in Europe |
| 1922 | Ernst Mahle joins the company |
| 1924 | Company renamed Elektronmetall G.m.b.H., Stuttgart-Cannstatt (EC ) New lightweight pistons for motorsport activities |
| 1926 | Hermann Mahle appointed Commercial Director |
| 1927 | Ernst Mahle appointed Technical Director |
| 1929 | Series production of air, oil, and fuel filters |
| 1930 | First cylinder liners made of nitrided steel |
| 1931 | Ring carrier piston registered for patent |