What is a laser nozzle?
Laser cutting is recognized as one of the metal processing methods with high efficiency, high quality, and high precision. Many factors affect laser cutting, and the laser nozzle is one of them.
A laser nozzle is one of the most important parts of a laser cutting head. The nozzle is located at the lower end of the cutting head. The laser beam and auxiliary gas act on the cutting material through the nozzle. Its main function is to gather the auxiliary gas and form high pressure, release it to the surface of the cutting material and the cutting laser beam, blow away the melted and vaporized parent material generated during the cutting process, and leave a clean cutting seam; at the same time, prevent slag, smoke, and other pollutants from rebounding upwards, thereby protecting the protective lens.
Whether the laser beam and the nozzle are concentric&coaxial is the key factor in laser cutting quality
To get a better cutting section, it is necessary to control the concentricity of the laser beam and the center of the nozzle, which is one of the important factors affecting the cutting quality. Therefore, the nozzle and the laser beam must be coaxial for a better cutting section.
When the center of the nozzle is not coaxial with the center of the laser beam, the impact on the cutting quality is as follows:
1. The cutting gas is ejected from the center of the nozzle, and the center of the nozzle is the same point as the plate to be cut. Suppose the laser is not in the center of the nozzle. In that case, the laser action point will deviate from the actual point and the cutting quality is not good.
2. If the laser beam is not in the center of the nozzle, the beam will hit the inner of the nozzle during the working, after that the nozzle will be burned, affecting cutting also.
Here is a guide for you How do you adjust the laser to the center of the nozzle?
Nozzle type selection
The single-layer nozzle has a relatively slow gas flow rate and is often used to cut stainless steel, aluminum alloy, copper and other metals. Nitrogen is often used as an auxiliary gas. The double-layer nozzle has a fast gas flow rate and is suitable for high-speed cutting. It is often used to cut carbon steel and generally uses oxygen as the auxiliary gas.
An experienced operator can make other nozzle sizes work well with a different combination of feed rate, laser power, and assist gas pressure.
Here are some different tips for choosing a laser nozzle: orifice size, chrome or non-chrome plating, single or double nozzle, and the surface area of the nozzle near the cutting area. In some cases, there are also options for internal shapes that affect the assist gas flow, such as conical or cylindrical.
You will see more and more nozzles with chrome plating, which helps further extend the span life of the nozzle. The chrome finish provides a harder surface that is more durable and has a stronger resistance to metal spatter.
The below table is a guide for you to choose the right nozzle 😀
| Name | Code | Shape | Features | Application |
| Single nozzle | “S”Single nozzle |  | The inner is conicalHigh-pressure gas and blowing slags with a higher flow rate | Air or oxygen cutting for: stainless steel, galvanized sheet, aluminum sheet and other materials |
| Double nozzle | “D”Double nozzle |  | Double-layer compositedBased on the single-layer,Added an inner core | OxygenCutting for: (double layer 2.0 size and above )for carbon steel sand surface cutting |
| High speed double nozzle | DE nozzle |  | The nozzle tip is sharped. The three holes on the inner core edge are larger than the ordinary double-layer nozzle | OxygenMainly used for high-power and high-speed bright surface cutting of carbon steel less than 20mm |
| High speed Single nozzle | SP nozzle |  | The nozzle tip is sharped. And the inner is a stepped cone | Mainly used for high-power, high-speed bright surface cutting or oxygen negative focus cutting of carbon steel with a thickness less 20 mm |
| High speed Single nozzle | ST nozzle |  | The nozzle tip is sharped and has a conical inner . The nozzle’s caliber is larger than SP nozzle. | Mainly used for high-speed bright surface cutting of carbon steel with a thickness of more than 20m. |
| Pressurizing nozzle | Boost nozzle |  | Based on single-layer nozzleThe nozzle has a step | Mainly used for high power nitrogen or air low pressure cutting of stainless steel and carbon steel. |
Different cutting materials requirements:
The single-layer nozzle is mainly used for nitrogen cutting of stainless steel and aluminum plates; The double-layer nozzle is mainly used for oxygen cutting of carbon steel.
Nozzle’s Caliber:
The caliber size of the nozzle determines the flow rate of the gas and the shape of the gas field. Generally, when cutting thin plates less 3mm, it is recommended to use a nozzle with a caliber of 1mm, and a nozzle with a caliber of 1.5mm is recommended for cutting 3-10mm and more than 10mm caliber is 2mm or more.
If you want to know more fiber laser cutting parameters please feel free to Contact us – Wewinlaser
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