By definition steel is extremely tough and hard to cut. Thankfully, there are several technologies and machines that have been specifically designed to cut and shape all grades and thicknesses of steel. High definition plasma machines are one such technology that offers incredible accuracy and efficiency when cutting mild steel, stainless steel and aluminium between 3mm-25mm.

In this article, we explore the process of high def plasma cutting and how it compares to other cutting technologies such as oxy fuel.

Plasma cutting basics

Plasma cutting is a process that involves blowing a gas (oxygen, air, inert and others) at high speed out of a nozzle, while at the same time sending an electrical arc through the gas turning it into plasma. The plasma is hot enough to cut metal and moves fast enough to blow the molten metal away from the cut.

High definition plasma (aka HD plasma, CNC plasma, and high density plasma) is the latest in plasma cutting technologies, in which the plasma arc is forced through a smaller nozzle to achieve cleaner, squarer cut edges while at the same time achieving acceptable parts life in the torch.

Modern high def plasma machines can achieve amperages from 130 to 800 and cut carbon steel up to 76mm thick, however it works best on thickness between 3mm-25mm. The technology also allows for high levels of automation, adding to the quality, speed and ease of use and making it the method of choice for metal fabricators worldwide.

HD Plasma vs Oxy fuel Cutting

HD plasma is one option among several other steel cutting technologies, including oxy fuel and laser. Each has been developed for use in different applications. For instance, plasma cutting is ideal for cutting steel and non-ferrous metals, including mild steel, aluminium and stainless steel. It is typically much faster on thinner materials (less than 25mm thick) and is more efficient on non-linear cuts than oxy fuel machines.

For heavier section steels (up to 300mm thick), oxy fuel cutting becomes more efficient as it can cut faster at these thicknesses while using less power. The immense heat that is produced can cause warping on thinner sheet metal, which is another reason why plasma cutting is better for these materials.

Further, as oxy cutting cuts by burning the metal, the process is limited to metals that support the oxidisation process, thus excluding aluminium and stainless steel. For these metals, again, high definition plasma is best.