Hot Rolled Steel Sheet: Being Precise, What Is That?

            Out of all the different variations of steel, a hot rolled steel sheet does not have the strict requirements to be exactly perfect.  The process of turning a slab of steel in to the hot rolled sheet variety plays a major role in the inconsistencies of the metal.  When it comes to producing a hot rolled product, “as long as it’s in the ball park” can be considered perfection.

                        

            Making hot rolled steel involves subjecting the steel to heat above its recrystallization temperature, typically over 1,700 degrees Fahrenheit.  As the steel reaches these temperatures it is capable of being shaped and formed quite easily.  The most popular way of shaping and forming malleable steel is with a mill process called hot rolling.  Once the steel is heated to the proper temperatures it is fed through a set of rollers that reduce the thickness of the steel to a predetermined measurement.  This process is somewhat similar to rolling out bread dough with a rolling pin.  By applying pressure, chemical properties of the steel are spread out creating a product much larger in size.

            After the steel has been through the rolling mill it is left to cool.  As the steel returns to a solid state, it loses some of its size making it difficult for hot rolled steel to meet exact measurements.  These inconsistencies in size are one of the reasons hot rolled steel is used in situations where precise shapes and tolerances are not mandatory. 

                     

            Surface condition is another aspect of the hot rolled steel that limits its use in projects where surface is a major factor.  A blue scale finish is left behind from the hot rolling process and it is done completely by accident.  Since this finish is not controlled, the surface can be somewhat different from sheet to sheet.

            Inconsistencies in the finished product which is hot rolled steel are not the only reason for it being less expensive than its cold rolled counterpart.  During the hot rolling process, heating up the steel only occurs once.  In the cold rolling process, the steel has to be heated and cooled multiple times.  This additional processing is the primary reason why hot rolled steel is less expensive than cold rolled steel. 

                                     

            Hot rolled steel is generally manufactured for structural components such as I-beams or cross sections for railroad tracks.  Compared to cold rolled steel where durability, tolerance, and surface condition or vital, it is much less crucial for hot rolled steel to be precise.

            For obvious reasons, sheets of hard rolled steel just are not the answer.  Sometimes a more durable and exact material better suits the project.  Although, when the time comes to throw a project together quickly, without a care in the world about surface condition or strength, hot rolled steel sheets are the answer.  Hot rolled steel is fairly inexpensive when compared to other forms of steel and it is not too difficult to work with.