The 4130 mechanical structure tube is a high-strength, low-alloy steel commonly used in a variety of structural applications, including the aerospace, automotive, and oil & gas industries. It is known for its combination of excellent strength, good weldability, and versatility. The steel gets its name from its composition, containing primarily carbon (0.30–0.40%), chromium (0.80–1.10%), and molybdenum (0.15–0.25%), along with traces of other elements like manganese, silicon, and sulfur.