The metal is prepared from the powder made by the hydrogen reduction of purified molybdic trioxide or ammonium molybdate. Molybdenum the metal is silvery-white, and very hard.

Molybdenum metal is used in:

• Alloying agent - contributing hardenability, toughness to quenched/tempered steels. It also improves the strength of steels at high temperatures (red-hardness).
• In nickel-based alloys (such as Hastelloys®) and stainless steels it imparts heat-resistance and corrosion-resistance to chemical solutions.
• Electrodes for electrically heated glass furnaces and forehearths.
• Nuclear energy applications, as missile and aircraft parts (where high temperature resistance is vital).
• As a catalyst in the refining of petroleum.
• As a filament material in electronic/electrical applications.
• As a support members in radio and light bulbs.
• Arc resistant electric contacts.
• Thermocouple sheaths
• Flame- and corrosion-resistant coatings for other metals (generally arc deposited for metallising).

Plants and animals generally have molybdenum, present in amounts of a few parts per million. In plants, molybdenum is involved in the pathways of nitrogen fixation and nitrate reduction, and in animals, molybdenum is involved in the pathways of purine degredation and formation of uric acid. In some animals, adding a small amount of dietary molybdenum enhances growth.

Molybdenum is also an essential trace mineral needed for the proper function of certain enzyme-dependent processes, including the metabolism of iron.

Toxicity Symptoms
Symptoms of excessive molybdenum include:

• joint pain,
• side, lower back, or stomach pain,
• swelling of feet or lower legs

Toxicity Limits
The estimated range of organic molybdenum recommended by the Food and Nutrition Board as safe and adequate is 75-250 mcg per day for adults. There should not be any concentrations of inorganic molybdenum.