Sheet metal is a thin sheet of metal that is formed by hot or cold rolling. Sheets can be made of nearly any type of metal such as: steel alloys, nickel alloys, copper, brass, and aluminum, titanium, etc. The thickness of the sheet is defined by the gauge size and different gauge sizes refer to different sheet thickness. A higher gauge actually refers to a thinner sheet while a lower gage identifies a thicker sheet. The gauge of sheet metal ranges from approximately 30 to eight gauge. Very thin sheets of metal are classified as foil.
The process of rolling has been around for a few centuries now. It works by taking the metal and compressing it through a set of rolls. The metal is then drawn and stretched in to a thin sheet. Stretching is performed when the metal is clamped at its edges and is then stretched over a die, or a form block. Stretching is usually done to metal that is used for constructing car doors, window panels and airplane wings.
Drawing is the method that is used to form sheet metal into cylinders and boxes. In this process a punch is used to press the metal into a cavity to form it into the desired shape for the task it is going to be used. In deep drawing, the depth of the metal part is greater than the part’s diameter. This process is commonly used for making deep containers such as kitchen sinks and automobile fuel tanks. The processes of bending and flanging are designed to add some stiffness to a section of the sheet metal to form specific shapes. Punching and shearing refers to sheet metal that is cut by using a punch and die.
Sheet metal is used in various things such as automobiles for body and panel building, in machine tools, electronic components to make the body, electrical devices, contacts, propellers and blades running at low speed, covers, airplane wings, roofing, and toys, etc.
Sheet metal can be cut and subjected to various machining and forming processes such as drilling, boring, drawing, deep drawing, slitting, punching, shearing, and cutting, etc. Sheet metal can be powder coated, painted and heat treated. Sheet metal products act more as covers than they do as structures as they are not designed to stand up to excessive force and cannot be used as elements to transmit power.