While metal is generally hard and tough, it is still able to be cut by several different processes. Understanding what the processes are and which option is best suited for specific metal types and projects is important when determining how to cut metal. Here are some common ways to cut metal.

Thermal Cutting Processes

There are several different thermal cutting processes that can be used to cut metal. These processes use an energy source to heat specific portions of the metal and cause it to become liquid. At that point, the molten metal is blown away from the rest of the solid metal, creating a cut. Thermal cutting is preferred over other processes in certain applications because of the speed in which the metal can be cut.

·        Flame cutting is one example of a thermal cutting process. For example, oxy-fuel flame cutting uses the combination of oxygen and a fuel such as acetylene or propylene to create a flame that melts the metal. The flow of the oxy-fuel gas mixture is also used to blow the molten metal and create the cut.

·        Plasma cutting is similar to flame cutting, but instead of an oxy-fuel gas mixture, it uses an electrical arc as the source of heat.

·        Laser cutting is also a thermal cutting process, with laser energy being used to melt the metal. A monochromatic and coherent light beam is created within a laser resonator and focused through a lens onto the metal material. This causes the target sections of the metal to become heated and melt, resulting in a cut.

Mechanical Cutting Processes

Mechanical cutting processes use physical rather than thermal means to sever metal material. There are several ways that mechanical cutting can be carried out. The speed and cut quality vary greatly depending on the mechanical cutting process used.

·        Production saw cutting is performed using a band saw in the horizontal or vertical position. Production saw cutting is a relatively slow but very robust cutting process, as it can be used cut many different types and shapes of metal. Typically, a coolant is used in order to remove the heat that is caused by friction from the saw blade cutting the metal.

·        Shearing is a mechanical cutting process that severs metal by using a sharp edge that is pressed down with a large amount of force. The blade deforms the sheet until it eventually creates a cut. Shearing can produce high-quality cuts, although it can leave the metal with a deformed edge. Shearing is typically used for cutting sheet metal.

·        Miter cutting is another mechanical cutting process frequently used. Miter saws cut with a circular metal saw blade, often made out of carbides. The blade is spun and lowered into the metal material, making the cut. A unique feature of a miter saw is its ability to cut metal material at a wide range of precise angles.

·        Hole punching is a cutting method similar to shearing. When punching, a metal tool (which can have a variety of shapes) with sharpened edges is depressed onto a metal material until it is severed. Punching is mostly used to cut certain shapes into a metal.

·        Notching is frequently done by using the punching process. A common application of notching is removing material from a metal sheet or plate so that it can be shaped three dimensionally.

·        Drilling is similar to hole punching. It typically is not used to sever a material, but to cut a shape into a material. Drilling pushes a drill bit into the metal to remove material. Most drill bits cut cylindrical holes into a material, however, a countersink bit can be used to make a conical cut into a metal.

·        Water jet cutting is another type of mechanical cutting process in which water is forced through a nozzle at extremely high pressure. Water alone can be used to sever soft materials, however, the water is almost always combined with an abrasive material that helps to erode the metal being cut.