section_path: Applications/As structural material/Mechanical properties
section_name: Mechanical properties
paragraph_text: Mechanical properties
  
  The mechanical properties of iron and its alloys are extremely relevant to their structural applications. Those properties can be evaluated in various ways, including the Brinell test, the Rockwell test and the Vickers hardness test.
  
  The properties of pure iron are often used to calibrate measurements or to compare tests. However, the mechanical properties of iron are significantly affected by the sample's purity: pure, single crystals of iron are actually softer than aluminium, and the purest industrially produced iron (99.99%) has a hardness of 20–30 Brinell. The pure iron (99.9%～99.999%), especially called electrolytic iron, is industrially produced by electrolytic refining.
  
  An increase in the carbon content will cause a significant increase in the hardness and tensile strength of iron. Maximum hardness of 65 R is achieved with a 0.6% carbon content, although the alloy has low tensile strength. Because of the softness of iron, it is much easier to work with than its heavier congeners ruthenium and osmium.