Making Steel Laser Cuts: Should You Use Oxygen Or Nitrogen Gas?

Laser cutting still sounds high-tech to some people, but for those in the thermal machining industry, it’s become a very common tool. Like any tool, we are constantly learning ways to improve its performance and use it in new ways. One of the biggest influences on laser cutting is the shielding gas used. In many cases it’s a choice of nitrogen gas or oxygen.

Which gas to use depends on:

1. The type of material being cut.
2. The thickness of that material.
3. The desired edge quality.
4. The processing speed.

When To Use Nitrogen Gas

Nitrogen gas is best used to:

• Cut stainless steel or aluminum.
• Act as a shielding gas in light gauge materials.
• Achieve excellent edge quality.
• Cut in high power applications.

Nitrogen cutting speed is directly related to the power of the laser. High-powered lasers can cut faster and boost production times – but only if nitrogen gas is used and only up to certain thicknesses. Nitrogen gas works best in steel that is up to 1/8 inch thick. Anything thicker than that will cut faster with oxygen as the shielding gas.

Edges that must be superior quality benefit from nitrogen gas shields. Nitrogen edges are free of impurities like oxidization, making them especially receptive to powder coat paints.

When To Use Oxygen

Oxygen is most commonly used to:

• Cut thicker steels.
• Cut in low power applications.
• Cut when edge quality is unimportant.

Oxygen limits the amount of power that can be applied to the cut. At higher powers, the cut edge quality decreases and burn risk increases. For that reason, most manufacturers use oxygen only with low-power lasers.

Oxygen typically costs less to use than nitrogen because you can use less of it to achieve the same amount of cuts, but this greatly depends on the amount of cutting you’re doing and the thickness of those cuts. Thicker cuts will cut faster with oxygen due to its reaction with iron. This causes burning to increase and you’ll use less gas.

Making The Choice

So what does this all mean for your gas selection? In general, you can use nitrogen in applications with thin steels and in situations where, if by doing so, you can increase your processing speed and improve the quality of your cuts. It’s also a good choice if there is a lot of secondary operational work required on the piece. As materials become thicker, you may find oxygen to be the better choice. It all depends on how much secondary work is needed and if the cost of that work outweighs the costs of additional nitrogen gas.

Order Shielding Gas From Josef Gas

Overall, it might take some trial and error to find the best gas for your application needs. Test out the different shielding gases or get advice from the pros at Josef Gas. We love to work through problems and help our customers find the best solutions to their manufacturing needs.

Call Josef Gas today at 416-658-1212 or email us at info@josefgases.com to learn more about our services and products.