When it comes to industrial applications, there are many cutting methods available. However, in general, there are three kinds of industrial cutting methods that are popular: thermal cutting, erosive cutting and mechanical cutting.
A thermal cutting process is when heat is used to cut or melt through the material being cut. Most of the industrial metal fabrication processes use one of the three thermal cutting processes – oxyfuel flame cutting, laser beam cutting or plasma arc cutting. The choice of the thermal cutting method depends on the type of metal, the thickness of material, cutting quality required and dimensional tolerances.
Oxyfuel Flame Cutting
In oxyfuel cutting, the chemical reaction between pure oxygen and steel produces a very high temperature that melts the metal. Pre-heated flames are used to raise the surface to ignition temperature and pure oxygen is then focussed toward the heated area in a fine, high-pressure stream that creates the cut. This method of cutting is restricted to carbon steel.
Laser Beam Cutting
In laser beam cutting, a high-power beam of light is produced inside the laser resonator and focused onto the metal surface. This heats and melts the metal while the melted waste is blown away by the gas. Gases such as nitrogen or oxygen are used to eject the molten metal out of the cut kerf.
Plasma Arc Cutting
Plasma arc cutting uses a high-speed jet of ionized gas or plasma, which is constricted through a tiny orifice in a nozzle to cut metal. The plasma heats the workpiece, melts the material and blows the molten metal away. Plasma arc cutting can be used to cut any kind of conductive metal.
Erosive cutting is a process of cutting that uses water, air or any other natural agent to wear away or erode material. Waterjet cutting falls under the category of erosive cutting.
When a high-pressure volume of water travels through a very small orifice, it creates a high-speed stream of water. In water-only cutting, this high-velocity water stream erodes the material being cut. Abrasive waterjet cutting uses a high-velocity water stream that is mixed with an abrasive, usually garnet, that erodes the material being cut.
Abrasive waterjet cutting is usually used to cut harder materials such as stone and metal.
Mechanical cutting makes use of physical forces to cut an object. Examples of mechanical cutting are drilling, sawing and shearing. In this kind of cutting, the cutting mechanism such as a blade is placed in physical contact with the object that is being cut.
Mechanical cutting processes can be either manual or automated.