The density of aluminum ​is often used in the calculation of aluminum profiles. Aluminum is a chemical element belonging to the boron group. Its chemical symbol is Al and its atomic number is 13.

Aluminum has the advantages of lightness and sturdiness, and it is an ideal material for "lightweight automobiles". Experiments by international research institutions show that if the weight of the vehicle is reduced by 10%, the fuel efficiency can be increased by 6% to 8%.