Molybdenum is used efficiently and economically in alloy tool steel improve hardenability reduce temper embrittlement resist hydrogen attack & sulphide stress cracking increase elevated temperature strength improve weldability, especially in high strength low alloy steels (HSLA) In the present section the focus is on grades and properties of Mo containing alloy steel and iron. End uses cover the whole world of engineered products for: Automotive, shipbuilding, aircraft and aerospace Drilling, mining, processing Energy generation, including boilers, steam turbines and electricity generators Vessels, tanks, heat exchangers Chemical & Petrochemical processing Offshore; Oil Country Tubular Goods (OCTG) In most cases molybdenum is needed to meet the high end of the application properties, which is accomplished with comparatively small molybdenum additions. In fact, with the exception of High Speed Steel and Maraging Steel the Mo content often ranges between 0.2 and 0.5% and rarely exceeds 1%.