Levi's® Vintage S501®XX 1944s Original Rigid JeansAfter the WW II, the United States government informed all clothing manufacturers that they had to remove a certain amount of metal, fabric and thread from their garments in order to conserve the raw materials for the war effort. Levi Strauss & Co. did what it could to abide by the rules. Off came the watch pocket rivets, the crotch rivet and the cinch, along with its two rivets (which eliminated both fabric and metal.) Buttons became standard issue