With war imminent, Vollrath gradually converted to war work in late 1941, increasing the government supplies monthly until August 1, 1942. At that time, Vollrath was 100% on defense work, which continued throughout the war. 

Vollrath also supported the war effort by supplying the government with many practical hospital and mess items, as well as endorsing the purchase of war bonds locally and in national advertising. 344 Vollrath employees joined the armed forces. 

On June 28, 1945, Vollrath was awarded the Army-Navy “E” Flag for its record in the production of materials needed in the war effort. Vollrath produced more than 12 million canteens during the war, along with many other products for military use, such as mess trays, meat cans, irrigators, and basins. Lapel pins were given to the 764 Vollrath employees in recognition of this accomplishment.