300M Consumable Electrode Vacuum Remelted Steel is 4340 Alloy Steel modified with the addition of Vanadium and higher Silicon. Carbon Content in AMS 6417 Carbon content is 0.37% to 0.43”. Specifications AMS 6419 requires 0.40” – 0.45% C and AMS 6256 0.40% - 0.44%C. Service Steel Aerospace stocks material with restricted carbon content to certify chemistry to these various specifications. These chemistry modifications provide an Alloy Steel with very good fatigue strength, ductility, impact strength and fracture toughness. 300M is widely used for Aircraft Landing Gear.