AISI 4340 Tubes are high-strength alloy steel tubes made from a nickel-chromium-molybdenum (Ni-Cr-Mo) steel grade known for its exceptional toughness, wear resistance, and fatigue strength. These tubes offer superior mechanical properties even under extreme loading conditions, making them suitable for critical structural and engineering applications. The tubes are typically delivered in quenched and tempered or normalized and tempered conditions to achieve high hardness and tensile strength.
The chemical composition of AISI 4340 typically includes 0.38–0.43% Carbon, 0.60–0.80% Manganese, 1.65–2.00% Nickel, 0.70–0.90% Chromium, and 0.20–0.30% Molybdenum. This alloy combination enhances the steel’s ability to withstand high stress and fatigue without compromising ductility. AISI 4340 tubes exhibit excellent through-hardening capabilities, making them highly suitable for components that experience high impact, torque, and cyclic loading. The typical tensile strength ranges from 930 MPa to 1080 MPa, depending on the heat treatment.
