Frequently Asked Questions

General FAQs

What kinds of gases are used in Oxy-fuel cutting?

The Oxy-fuel gases used include oxygen, acetylene and liquefied petroleum gas (LP Gas); last two provide the high temperature Preheat flame.

How do I cut materials that are not in the cutting charts?

The answer depends upon the composition of the material that needs to be cut. Most cut charts cover the basics: carbon (mild) steel, stainless steel and aluminum. Metals such as copper and brass can be cut using the same parameters as carbon steel, with a slight reduction in speed due to their heat sinking properties. Other materials like titanium and INCONEL® can be processed using stainless steel parameters. With the multitude of alloys available today, the best advice is to contact your torch manufacturer for their recommendations. This will save you both time and material. (INCONEL is a registered trademark of Special Metals Corporation.)

Can I cut underwater?

The short answer is yes; however, there may be some loss of part quality and cutting speed due to the cooling properties of water. It is generally recommended to keep the water level a minimum of one inch below the plate at all times. This will allow for smoke absorption while retaining optimal results for both cut quality and speed.

What gasses do I need to cut carbon steel, stainless steel, and aluminum?

High density plasma systems, require oxygen, nitrogen, and air for carbon steel and aluminum. A mixture of hydrogen and argon may be used for stainless steel. Conventional plasma uses air to cut all materials.

Can I use my shop compressor instead of air cylinders?

Oxy-fuel cutting is a chemical reaction between pure oxygen and steel to form iron oxide. It can be described as rapid, controlled rusting.

How does Oxyfuel Cutting work?

Air compressors can be used to supply high density plasma systems as long as a few requirements are met. The most important is that the air is clean and dry to prevent reduced cut quality, consumable damage, or torch failure. It is recommended that the air is filtered to ISO 8573.1 Class 1.4.1 (particulates, moisture and oil). Secondly, the compressor must be able to maintain the minimum input pressure needed to operator the plasma system. Check the specifications section of your operator’s manual for the requirements of your plasma system before connecting to an air compressor.

Should I choose a water table or downdraft table?

Both table types have their pros and cons. A water table requires a smaller initial investment, has lower maintenance costs and effectively eliminates most of the smoke and noise associated with plasma cutting. The downside is that it doesn’t take long for the water to become infused with dirt and metal dust. If proper care is not taken, the water can contaminate the torch and disrupt gas flow in the consumables, which results in a loss of cut quality. Conversely, downdraft tables are more expensive due to the cost of the air handler and filtration systems, as well as the need to regularly replace as many as six filters. However, since they avoid the problems associated with water tables previously discussed, they contribute to optimum cut quality and are, therefore, preferred for high density plasma cutting.

I want to buy a CNC plasma cutting machine, but do I need the automatic or manual gas console?

If you plan on cutting multiple material types (mild steel, stainless, aluminum, etc.) during a shift, and plan to do so regularly, then the automatic gas console is the best choice. This PC-based control requires the operator to input only the material type and thickness, then it automatically selects the optimum cutting amperage, the gasses needed to cut the material, and finally sets the correct pressures according to the pre-loaded cutting charts. So if you are planning to purchase, please click here

How do I choose the amperage that is right for me?

You must first determine your current cutting capacity requirements, or decide what capabilities you would like to have in the future.

How many consumables do I need to stock?

This is based on your production requirements. Most plasma systems have eight or more amperage options; each has its own specific set of consumables. Stocking requirements will vary depending on how many different plate thicknesses you cut on a daily basis.