In fact, both hot rolling and cold rolling need heating, but one temperature is above 700 degrees and the other is around 400-500 degrees.

The surface of hot rolled steel is generally black or reddish brown, and the surface of cold rolled steel is bright silver.

Cold-rolled steel plates are generally below 3mm, and the thickness of hot-rolled steel plates is generally above 3mm or below 3mm, but these two materials can be distinguished by naked eyes or touch.