Hot Rolled. Hot rolling is a mill process which involves rolling the steel at a high temperature (typically at a temperature over 1700° F), which is above the steel's recrystallization temperature. ... Hot rolled steel is used in situations where precise shapes and tolerances are not required.
Application Usage: Automobile, Steel pipes, Construction, Oil pipes, etc
Cold Rolled Steel is essentially hot rolled steel that has gone through more processing. To get cold rolled steel, manufacturers generally take cooled-down hot rolled steel and roll it more to get more exact dimensions and better surface qualities.
Application Usage: Automobiles, Home Applicances, Industrial machines, Building Materials