4130 Carbon Steel Pipe is usually used in the quenched and tempered state. When the carbon content is at the lower limit, the steel can also be used as the carburized steel with higher central strength. In the medium-sized machinery manufacturing industry, it is mainly used to manufacture quenched and tempered parts with large cross section and working under high stress conditions, such as shafts, main shafts, and operating wheels, bolts, studs, gears, etc. under high load; In the chemical industry, it is used to manufacture welding parts, welding structures composed of plates and pipes, and high-pressure conduits with a temperature not exceeding 250 ℃ when working in medium containing nitrogen and hydrogen; In the steam turbine and boiler manufacturing industry, it is used to manufacture fasteners for work below 450 ℃, flanges and flange covers subject to high pressure below 500 ℃. The better weldability also makes 4130 Carbon Steel Pipe a popular choice in the aerospace industry, which is used to manufacture commercial and military aircraft components requiring high strength and low weight. Examples include gears, piston pins, etc. Other uses of 4130 steel include auto parts, cutting tools and drilling machines.