The main steel grade includes 20#、30#、40#.High quality carbon structure steel refers to the carbon steel with carbon component less than 0.8%. The component of sulfur, phosphorus and nonmetallic materials of this kind of steel with excellent mechanics performance is less than that of carbon structure steel. After cold rolling, it can be widely used in chains, measuring tools, cutting tools, safety belt buckle, saw blade, hardware products, etc. Gauge cover（2-12）*（1010-2000）mm