1,Size of 4340 Alloy Steel Round bar Diameter(mm) Length (mm) 20~800 3000~9000 Plate Thickness(mm) Width (mm) Length (mm) Max:800 Max:2200 Max:9000 The specification can be customized. 2,Chemical Compositons C Si Mn P S Cr Mo Ni 0.38-0.43 0.15-0.35 0.60-0.80 â?¤0.035 â?¤0.040 0.70-0.90 0.20-0.30 1.65-2.00 3,Features of 4340 alloy steel 1, Chromium molybdenum alloy steel; 2, High strength and toughness; 3, Good stability of hardenability and anti-overheating; 4, Good high tensile strength with shock resistance. 4,Typical Applications 1, Heavy machinery and high-load of shaft; 2, Rotor shaft and blades; 3, Special performance requirements of the vital parts after nitriding treatment. Songshun Company Introduction Located in Chang'an Town - the famous town of mould in Pearl River Delta; Providing complete services from manufacturing and marketing to distributing; Steel exported all over the world; Service like peeling,milling,grinding,cutting and heat treatment etc... All steel must pass high quality detection; 24/7 hours online service with quick response !