Physical characteristics
The characteristics of steel

The color of steels can vary according to their chemical composition and heat treatment. Carbon steels may have a gray or dark blue color due to the presence of carbon, while stainless steels generally have a silver color due to the presence of chromium and nickel.

The color of steels can also be affected by heat treatment operations, such as annealing, which can give a reddish or blue color. However, it is not a reliable indicator of physical properties such as density, melting point, thermal or electrical conductivity. These properties must be determined by specific tests for each steel.