At the start of World War II a brass shortage made is necessary to create 40-mm cartridge cases out of steel. The government chose the Detroit firm of Clayton & Lambert to the solve the problem and produce 36 million cases at a plant in Ashland, Kentucky where the steel was made and a French Road-Detroit Plant where the cases were actually produced. These pieces are from Detroit. The first is a 1" with "I'll Strive" slogan while the others are 1.25" issued one per month and reading both "Keep 'Em Firing" and "On Job One Hundred Percent." The monthly series is complete from January through December with exception of July and August. Each button is marked on back by maker Bastian's union bug. Pink color on the June button has faded but otherwise all are essentially Mint as issued. A rare group. Morry Greener Collection.