Sheet Metal Cutting: Popular Methods in Industrial Applications

Popular Sheet Metal Cutting Methods in Industrial Applications

In the metal fabrication industry, five sheet metal cutting methods are widely popular. They are laser, waterjet, plasma, oxy-fuel, and mechanical cutting. Each of these methods differs by its working principle, applications, and type of products it makes.

Laser Cutting

The laser cutting method is an industrial process that uses a high-energy laser beam to cut metals. As you know, it’s a non-contact method, ensuring a safe and high-precision outcome from each cutting. You may also consider it a sheet metal cutting tool.

How to cut sheet metal via the laser cutting method? It can be highly automated for precise cutting. In the cutting process, the machine creates a coherent beam of light from the laser source and directs it to the material spot.

The laser source typically creates the laser beam and sends it to the optics. Optics, on the other hand, manipulate this laser beam to focus on the target spot. Later, with the help of CNC machining, the laser gun moves along the designed path. Once the laser beam hits the surface, it continues to heat the area until it melts, vaporizes, or burns away.

During the process, you might want to use some auxiliary gases to remove the melted metals. In most cases, oxygen, nitrogen, and others can be used. This way, you can ensure high-quality and clean edges at the cutting spot.

In industrial applications, the laser cutting method is typically used to cut materials ranging from 0.1mm to 25mm thick. It is widely popular in various industries. You can think of any sector that involves metal fabrication.

Pros

1. Exact and accurate with intricate design at lower tolerances
2. Cutting-edge quality is excellent
3. Versatile method with minimal material waste

Cons

1. The initial cost is high.
2. No specific advantage for linear cutting
3. Generally not suitable for reflective metals

Waterjet Cutting

The water jet cutting process uses a high-pressure stream of water to cut through the metal. The use of water allows the process to cool down quickly. Since it does not use any thermal elements, there is no chance of thermal stress, as it is cool.

A water jet pressurizes the water to extremely high levels (40,000 psi to 60,000 psi) and flows it through a nozzle. The nozzle is so small that it produces a focused and mighty stream with ease. Typically, it can reach speeds that are 2 or 3 times that of air. With this speed, it can easily cut almost all types of material.

You may use it for various purposes, including cutting marble, steel, aluminum, titanium, or other alloys. You can easily cut thick materials (0.1mm to 150mm) using the waterjet method. Mostly, it serves industrial work.

Pros

1. Can be used for cutting versatile materials
2. No Heat Affected Zone (HAZ)
3. The entire process is eco-friendly for using water

Cons

1. This method is not suitable for cutting thin or delicate materials. The pressure is high, which can easily cause damage to the materials.
2. The setup is complex and needs bigger spaces. You must also have a proper ventilation system. It adds to the final cost.

Plasma Cutting

Plasma cutting is a thermal cutting process that utilizes an ionized gas, also known as plasma. Here, a high-speed jet flows plasma to melt the metal and cut electrically conductive materials. It can cut metal thickness ranging from 3 to 50+ mm easily.

The process begins by creating an electric arc inside the electrode and the torch. Then, compressed gas, such as oxygen or nitrogen, is forced to flow through the nozzle. The arc then ionized these gases, converting them into a plasma state, which is the fourth state of matter. The temperature of the plasma state is around 40,000°F (22,200°C), which easily melts the underlying material, creating a clean cut.

The plasma cutting method is used in the shipbuilding and construction sectors. Also, it offers a cutting variety of conductive metals, including stainless steel, brass, and automotive parts. There are cnc plasma cutters that can cut detailed designs with accuracy and precision. It can often be portable for on-site work due to the flexibility of instant part replacement.

Pros

1. The initial cost is relatively lower than that of plasma and waterjet cutting.
2. Plasma cutting is faster than 0xy-fuet cutting
3. Reduce the post-processing work with minimal slag

Cons

1. This method is not suitable for cutting thin metals. There is a huge risk of warping or material damage.
2. Edge quality is good, but may have dross
3. The process is noisy and can generate hazardous fumes
4. The intense heat can also produce HAZ around the cutting

Oxy-fuel Cutting

Oxy-fuel cutting, also known as flame cutting, utilizes chemical reactions to cut metals. It is also a popular type of thermal cutting process, like plasma cutting. This cutting method is one of the oldest, simplest, and most widely used processes in the world.

Oxy-fuel cutting comes along with two steps: 1. preheating, and 2. cutting. In the primary stage, or first step, a torch uses a mixture of oxygen and a fuel gas, such as acetylene or propane. Thereafter, it creates a flame to heat the metal to reach its ignition temperature. When the metal is heated, a high-pressure jet releases oxygen from the torch to burn the surface, resulting in a clean cut.