Sheet metal fabrication refers to a classification of manufacturing processes which shape a piece of sheet metal into the desired form through material removal and even through material deformation. Sheet metal which acts as the work piece material in these processes is considered to be one of the most common forms of raw material stock. The material thickness which classifies a particular work piece as a sheet metal is not really that clearly defined. However, sheet metal is typically considered to be a piece of stock in between .006 and .25 inches thick. A certain piece of sheet metal which is often much thinner is considered to be foil and those that is thicker than this is referred to as a plate. The thickness of the piece of sheet metal is referred to as its gauge with a number typically ranging from 3 to 28. A higher gauge often times indicates a thinner piece of sheet metal, with the exact dimensions of the material depending on the material. Sheet metal stock is usually available in a wide variety of materials and usually involves the following: brass, aluminum, bronze, magnesium, nickel, copper, steel, stainless steel, zinc, tin, and titanium.
The sheet metal can be bent, cut and even stretched into different shapes. Material removal processes will also create holes and cutouts in any kind of 2D geometric shape. Deformation processes will also bend the sheet a couple of times to different stretches or angles the sheet in order to create complex contours. The size of the sheet metal parts will range from a small bracket or washer to midsize enclosures for home appliances and even to large airplane fuselage. These parts are often found in different industries like automotive, aircraft, consumer products, construction, furniture and even HVAC.
The process of sheet metal fabrication can mostly be placed within two categories: cutting and forming. Forming processes refer to those in which the applied force causes the material to drastically deform but not to fail. These processes are able to stretch or bend the sheet into the handler’s desired shape. Cutting processes are those in which the applied force will cause the material to fail and even to separate thus allowing the material to be removed or cut off completely. Most of the cutting processes are being performed by applying tremendous amount of shearing force in order to separate the material and will therefore be sometimes referred to as the shearing processes. Other cutting processes remove material with the use of abrasion or heat, instead of the more common shearing forces.
The processes involved when forming are the following: bending, spinning, roll forming, stretching forming and deep drawing. For cutting with shear, here are the following processes involved: blanking, shearing and punching. Should you choose to cut without having to shear, you can make use of the following processes: water jet cutting, plasma cutting and the more common laser beam cutting. The process to be used will depend of course on the project at hand and the style of the metal fabrication team.