Fabrication involves cutting, bending and assembling of raw materials to build structures. While a typical metal fabrication shop will accommodate all the three processes, each of them is independent and highly specialized. Cutting is the first concept of the fabrication process and has to be done right for the whole procedure to succeed. It is achieved through sawing, shearing and chiselling of raw materials to come up with sized metal shapes to work with. It can be done by either manual or powered tools depending on the immediate need. In industrial metal fabrication, wastage of material during the cutting process is inevitable. However, reducing scraps is still the top goal for metal workers and hence the need for precise cutting tools.
Advancements in technology have seen the emergence of modern cutting tools such as plasma and oxyfuel torches and numerical control cutters. Oxy-fuel torches use oxygen and fuel gases to weld the cut materials. The purpose of using oxygen instead of just air is to increase the flame temperature so as to allow localized melting of the workpiece. Advanced Metal fabrication shop workers use either propane-air, propane oxygen or acetylene-oxygen flames depending on their temperature requirements. Common propane-air flames burn at around 2000 degrees Celsius while propane-oxygen flames burn at 2500 degrees Celsius. Acetylene-oxygen flames are used when metal workers need hot flames reaching up to 3500 degrees, and are the most effective for hard materials and thick metal pieces. Oxy-fuel welding was developed during the early industrialization stages and was commonly used in cutting of raw materials for the early railway and bridge projects. Today, the concept is widely used through hand-held oxy-fuel torches that perform as effectively as electric cutting devices.
Plasma torches normally generate a directed flow of a plasma jet which ionizes airflow through the torch head to initiate an arch. The torch does not have to be in direct contact with the job material to deliver results. They are suitable for application that involve computerized numerical controlled cutting.