The L.S. Starrett No. 604R 6 inch Machinist Ruler is a high-quality, rigid rule made of tempered steel. Manufactured in the United States by L.S. Starrett Co., this ruler features a graduation style of 1604R and a length of 6 inches. It is a reliable tool for machinists and metalworkers for precise measurements and inspections in CNC, metalworking, and manufacturing processes. With its durable construction and accurate graduations, this ruler is essential for ensuring quality control in various industrial applications.