The main properties of interest for tungsten are:
· Tungsten is the heaviest engineering material with a density of 19.25 g/cm3
· It has the highest melting point of all metals at 3410°C
· It has the lowest vapour pressure of all metals
· It has the highest modulus of elasticity of the metals (E = 400GPa)
· It is the hardest pure metal
· Excellent high temperature strength characteristics
· It has the highest tensile strength at temperatures above 1650°C
· It has a low thermal expansion co-efficient (4.4x10-6 m/m/°C) similar to that of borosilicate glass, and therefore makes it useful for glass to metal seals.
· It does not oxidise in air and needs no protection from oxidation at elevated temperaratures
· Its corrosion resistance is excellent, and it is not attacked by nitric, hydrofluoric, or sulphuric acid solutions