Antique WWI Era U.S. Army Enlisted Collar Disk Screw Back Military Insignia Pin Original 1 Inch

An authentic World War I era U.S. Army enlisted collar disk, this original one-piece brass insignia features the bold raised "U.S." device worn on the right collar of enlisted soldiers' service uniforms during the First World War and the early interwar period. Measuring approximately 1 inch in diameter, the disk retains its original threaded screw post, matching retaining nut, and dual anti-rotation prongs that secured the insignia firmly to the uniform collar. The reverse bears an intertwined "PC" manufacturer's hallmark within a square cartouche, a documented but presently unidentified maker's mark recognized by military insignia researchers. The disk displays its original aged patina with honest wear consistent with military service and decades of preservation. Early screw-back collar disks were introduced beginning in 1910 and remained the standard style throughout World War I before later design changes and eventual wartime simplification. This original example would make an excellent addition to a collection of WWI U.S. Army militaria, American military insignia, uniform accessories, doughboy memorabilia, or early twentieth-century military history.