What are the most common industrial metal cutting methods? How to choose the appropriate cutting method?

There are common industrial cutting methods such as oxy-fuel cutting, plasma cutting, laser cutting, waterjet cutting, wire EDM cutting, and mechanical cutting (such as shearing and sawing). Below, we will introduce their principles, suitable cutting thicknesses, suitable metals for cutting, costs, and other advantages and disadvantages one by one.

Oxy-Fuel cutting 

Oxy-fuel cutting is one of the most widely used cutting methods in industrial metal cutting, offering advantages such as low cost and minimal pre-treatment requirements. It is extensively applied in the cutting process of carbon steel plates.

Principle: The process utilizes the heat generated by the combustion of oxygen and a combustible gas (such as acetylene, propane, or natural gas) to preheat the metal to its ignition point. A high-speed stream of pure oxygen is then sprayed onto the metal, causing it to burn vigorously (oxidize) in the oxygen and form slag. The kinetic energy of the oxygen stream blows away the slag, creating a cutting seam.

Applicable Thickness: It is highly suitable for medium-thick and thick plates, typically used for carbon steel plates over 6 mm thick, and particularly excels at cutting steel plates ranging from 40 mm to 500 mm or even thicker. For extremely thick plates (>500 mm), it is one of the most cost-effective options available.

Cost: Equipment cost: Low. The initial investment for a handheld oxy-fuel cutting system is significantly lower than other thermal cutting equipment. Operating cost: Low. The main consumables are combustible gas and oxygen, which are inexpensive.  

Advantages:  

1. Extremely low cost for thick plate cutting: In terms of cutting thick carbon steel plates, its equipment and operational costs are the most economical.  

2. Simple and portable equipment: The handheld cutting torch system is flexible and suitable for on-site operations, maintenance, and material preparation.

3. Large cutting thickness: It is the preferred method for cutting extremely thick carbon steel components.  

4. Low pre-treatment requirements: It is insensitive to rust and paint on the surface of steel plates.  

Disadvantages:  

1. Significant material limitations: It can only cut low-carbon steel and cannot cut stainless steel, aluminum, copper, and other non-ferrous metals.  

2. Large heat-affected zone: High heat input causes significant thermal deformation of the workpiece and changes in the microstructure of the material near the cut.

3. Low cutting accuracy: Rough cut edges with excessive slag, typically requiring secondary grinding and finishing.   

4. Slow cutting speed: Significantly slower than plasma or laser cutting on thin plates.   

5. Safety risks: Requires storage and handling of high-pressure gas cylinders, posing fire and explosion hazards.   

Plasma Cutting

Plasma cutting is a highly efficient and versatile thermal cutting process that has become a core piece of equipment in the field of medium- and thin-plate processing due to its fast cutting speed and ability to cut all conductive metals.

Principle: By using compressed air, nitrogen, or oxygen to form a high-frequency arc inside the cutting torch, the gas is heated to extremely high temperatures, causing it to ionize into a plasma state. This creates a high-temperature, high-speed plasma jet that melts the metal and blows away the molten material to achieve cutting.

Applicable Thickness: Suitable for thin plates and medium-thick plates. Handheld systems typically cut from 1 mm to 30 mm, while digital control systems paired with high-efficiency power supplies can efficiently cut up to 50 mm, with the ability to process metal materials exceeding 100 mm in thickness.

Cost: Equipment Cost: Moderate. Between oxy-fuel cutting and laser cutting. Operating Cost: Moderate. Primarily consumes electricity and wear parts (electrodes, nozzles), with gas costs depending on the type of gas used.

Advantages:

1. Wide range of materials: Can cut all conductive metals, including stainless steel, aluminum, copper, carbon steel, etc.

2. Fast cutting speed: Significantly faster than oxy-fuel cutting for thin and medium-thickness plates.

3. High cutting precision: Cutting quality superior to oxy-fuel cutting with minimal thermal deformation.

4. Underwater cutting capability: Reduces noise, dust, and arc light hazards.

Disadvantages:

1. Higher overall costs: Equipment and consumable costs are higher than oxy-fuel cutting.

2. Limited thick plate cutting capability: Although it can cut thick plates, cut quality and verticality deteriorate, and costs increase.

3. Beveled edges: The plasma arc forms a V-shape, causing the cut edge to have an upper-wide, lower-narrow bevel, particularly noticeable on medium-to-thick plates.

4. Generates noise and dust: Cutting produces significant dust and loud noise, requiring dust collection equipment.

5. Requires compressed air/gas: Has specific requirements for gas purity and pressure.

Laser Cutting

Laser cutting represents the trend toward high precision and automation in cutting. With its excellent cut quality and high degree of flexibility, it dominates the market for precision processing of thin plates and cutting of complex patterns.

Principle: A high-power laser beam is focused into a tiny spot through an optical system and irradiated onto the surface of the workpiece, causing the material to be rapidly heated, melted, or vaporized. At the same time, auxiliary gases (such as nitrogen or oxygen) are used to blow away the molten material.

Applicable thickness: The primary advantage lies in thin to medium-thick plates. Fiber laser cutting of carbon steel typically achieves excellent efficiency and quality within the 1mm to 30mm range, with the ability to cut up to 40mm. Cutting thicknesses for stainless steel and aluminum are generally lower. Ultra-high-power laser machines can handle carbon steel over 100mm, but economic viability decreases.

Cost: Equipment cost: High. It has the highest initial investment among various thermal cutting methods. Operating costs: Moderate to high. Mainly consumes electricity, auxiliary gases, and consumables such as lenses. Although the cost per piece may be low, equipment depreciation accounts for a high proportion.  

Advantages:  

1. Extremely high cutting precision: Narrow cut width, small tolerances, smooth edges, and burr-free cutting, typically requiring no secondary processing.  

2. Extremely fast cutting speed: In thin plate cutting, the speed far exceeds that of plasma and Oxy-Fuel cutting.

3. High flexibility: When combined with a CNC system, it can instantly switch to any complex shape, making it ideal for small-batch, multi-variety production.  

4. Minimal heat-affected zone: Heat input is highly concentrated, resulting in minimal deformation of the workpiece.  

5. Capable of precision processing: Can perform precise cutting of micro-holes, sharp angles, and other intricate details.  

Disadvantages:  

1. High equipment investment: The initial purchase cost is the primary barrier.

2. Low efficiency when cutting thick plates: As thickness increases, cutting speed decreases significantly, and the relative advantage over plasma cutting is lost.  

3. Sensitive to material reflectivity: Cutting highly reflective materials (such as copper, brass, and pure aluminum) is challenging, and reflected light may damage the equipment.  

4. Requires specialized operation and maintenance: Professional operators and a controlled maintenance environment are necessary.  

5. Material dependency: Different materials and thicknesses require different parameter adjustments (power, speed, gas).  

Waterjet Cutting

Waterjet cutting is a cold cutting technology that offers unique advantages such as no heat affect zone and the ability to cut any material, making it indispensable in specialized fields such as aerospace and stone processing.

Principle: Utilizes ultra-high-pressure water jets (typically mixed with abrasives such as garnet sand) to impact the material, achieving cold cutting.

Applicable thickness: Theoretically almost unlimited, but cutting speed decreases significantly with increasing thickness. Commonly used for precision processing of materials under 30mm, but can also cut extremely thick materials (e.g., over 200mm), though efficiency is very low.

Cost: Equipment costs are moderate, but operational costs are high (primarily due to energy consumption, abrasive consumption, and high maintenance costs).

Advantages:

1. No heat-affected zone (HAZ): This is the primary advantage, as it does not alter material properties, causing no deformation or hardening.

2. Extremely broad material compatibility: It can cut almost any material, including metals, stone, glass, ceramics, composites, plastics, and leather.

3. Environmentally friendly: No toxic gases or dust are produced during the cutting process.

Disadvantages:

1. Relatively slow cutting speed, especially for thick metal plates.

2. High operating costs, with significant abrasive and electrical energy consumption.

3. Nozzles and seals wear out quickly when cutting hard materials.

4. The cut edge may exhibit a certain taper (wider at the top and narrower at the bottom).

Wire EDM (Wire Electrical Discharge Cutting)

Wire EDM is specifically designed for the manufacturing of precision molds and parts. It uses electrical discharge to erode materials, achieving extremely high precision and processing high-hardness conductive materials.

Principle: A continuously moving molybdenum wire is used as the electrode. High temperatures are generated through electrical discharge to erode metal, primarily used for precision machining.

Applicable thickness: Depends on equipment specifications and workpiece material. Typically used for processing various thicknesses of precision small and medium-sized parts, particularly excelling in precision shape cutting of high-hardness conductive materials.

Cost: Moderate equipment cost, moderate operating cost (electricity, molybdenum wire, cutting coolant).

Advantages:

1. Extremely high precision, up to ±0.005mm or higher.

2. Capable of processing high-hardness conductive materials (such as quenched steel, hard alloys), unrestricted by material hardness.

3. Significant advantages in processing complex shapes and precision molds.

Disadvantages:

1. Can only cut conductive materials.

2. Relatively slow cutting speed.

3. Requires the use of cutting coolant (working fluid), which may cause environmental disposal issues.

Mechanical Cutting

Mechanical cutting, as the most traditional and economical cutting method, relies on shearing or sawing to separate materials. It is widely used in profile cutting and straight-line material handling due to its high efficiency and low cost.

Principle: Cutting is achieved through mechanical force or the mechanical movement of cutting tools, such as shearing machines, circular saws, and band saws.

Applicable thickness:  

Shearing machines: Suitable for straight-line cutting of thin plates (0.2–4 mm) and medium-thick plates (4–60 mm).  

Sawing (circular saws, band saws): Suitable for cutting bars, tubes, and profiles of various thicknesses, with a wide range of thicknesses.  

Cost: Equipment costs are low to moderate, and operating costs are low (primarily tool wear and electricity consumption).

Advantages:

1. Low cost, particularly suitable for large-volume straight or simple-shape cutting.

2. No thermal impact, does not alter material properties.

3. High efficiency (for specific shapes, such as straight lines).

Disadvantages:  

1. Only capable of processing straight or simple shapes (e.g., sawing), with limited flexibility and unsuitable for complex contours.  

2. Tools are subject to wear and require regular replacement.  

3. Shearing thin plates may cause deformation.

The following is a comparison table that includes cutting methods, working principles, suitable thicknesses, costs, advantages, and disadvantages:

Cutting Method	Main Principle	Suitable Cutting Thickness (Metal)	Relative Equipment Cost	Relative Operating Cost	Main  Advantages	Main Disadvantages
Oxy-Fuel cutting	Utilizes the heat generated by the combustion of oxygen and combustible gases to melt metal, and uses a high-speed oxygen stream to blow away slag.	Thick plates > 6mm, particularly effective for carbon steel over 40mm.	Low	Low	Low equipment investment, simple operation, suitable for thick carbon steel.	Large heat-affected zone, significant deformation, rough edges requiring grinding, cannot cut stainless steel, aluminum, etc.
Plasma Cutting	Utilizes high-temperature plasma arc to melt metal and removes molten metal with a high-speed plasma stream.	Medium-thick plates 1-50mm, with optimal results for 60-100mm.	Medium	Medium	Fast cutting speed, capable of cutting various conductive metals (stainless steel, aluminum, carbon steel), smaller heat-affected zone than flame.	Higher equipment and consumable costs, reduced cutting capability for thick plates (>100mm), produces a beveled edge, high noise and dust levels.
Laser cutting	Utilizes a high-energy-density laser beam to irradiate the material, causing it to rapidly melt and vaporize.	Suitable for thin to medium-thick plates; fiber lasers typically handle 30-100mm.	High	Medium to High	Extremely high precision, narrow cut width, high automation, good flexibility, suitable for complex shapes.	High equipment investment, low efficiency and high cost for cutting thick plates, challenging for cutting highly reflective materials (e.g., copper, aluminum).
Waterjet cutting	Utilizes the impact force of high-pressure water (mixed with abrasive) to cut materials.	Almost unlimited, but cutting speed decreases significantly with increasing thickness.	Medium to High	High	No heat affect zone, can cut any material (metals, non-metals, composite materials), environmentally friendly with no smoke or dust.	Slow cutting speed, high operating costs (energy consumption + abrasive), cut edges may have a taper.
Wire EDM cutting	Utilizes high temperatures generated by electrical discharge to locally melt the material.	Depends on equipment power and workpiece material, typically used for precision small to medium-sized parts.	Medium	Medium	Very high precision, capable of processing high-hardness conductive materials.	Can only cut conductive materials, slow cutting speed, requires cutting coolant.
Mechanical cutting	Separates materials through mechanical movement of tools (such as shearing, sawing) .	Shearing machines are suitable for thin plates (0.2–4 mm) and medium-thick plates (4–60 mm).	Low to Medium	Low	Low cost (shearing, sawing), no heat affect, high efficiency (for straight or simple shapes)  .	Can only process straight or simple shapes (shearing, sawing), tool wear, poor flexibility, unsuitable for complex contours.

So, how should we determine and select the cutting method?

The most important factor in determining the cutting method is the type of material to be cut. Different cutting technologies can cut significantly different materials. The following are the materials that are suitable and unsuitable for various cutting methods.

Oxy-Fuel Cutting

It is highly suitable for mild steel because oxy-fuel cutting is essentially a vigorous oxidation reaction process. Pure oxygen is blown onto preheated mild steel, reacting with iron (Fe) to form iron oxide (slag) and releasing a large amount of heat, thereby achieving self-sustaining cutting. The chemical composition of mild steel (primarily iron) is highly suitable for this process.

Not suitable for stainless steel, aluminum, copper, cast iron, and almost all other non-ferrous metals. Stainless steel (Stainless Steel): Contains alloy elements such as chromium (Cr) and nickel (Ni). These elements form a high-melting-point oxide layer (e.g., Cr₂O₃), which creates a dense oxide film that prevents oxygen from continuing to react with the internal iron, thereby interrupting the cutting process. The cut edges will be uneven and unable to penetrate completely. Aluminum (Al): A high-melting-point aluminum oxide (Al₂O₃) film (melting point approximately 2050°C) forms rapidly on the surface, far exceeding aluminum's own melting point (660°C). This film prevents further oxidation, and molten aluminum has low viscosity, making it difficult for the oxygen flow to carry it away; instead, it tends to adhere together. Copper (Copper) and Brass (Brass): These are excellent thermal conductors, causing heat to dissipate rapidly from the cutting point, preventing the temperature required for the initial oxidation reaction from being reached. Additionally, the melting point of copper oxide is lower than that of copper itself, preventing a continuous cutting process. Cast Iron: The melting point of cast iron is lower than that of its oxide. During cutting, the molten material is blown away before the oxide, resulting in an interrupted reaction and poor cut quality and precision.

Plasma Cutting

Plasma cutting is highly suitable for all conductive metals. The principle behind plasma cutting is a physical process (high-temperature melting) rather than a chemical process. As long as the metal is conductive, the plasma arc can form a circuit and melt it. Therefore, there are no chemical restrictions on the materials being cut, which is its greatest advantage over Oxy-Fuel cutting. Stainless steel and aluminum are the primary applications for plasma cutting, with excellent results. Carbon steel can also be cut efficiently, particularly in thin sheets and medium-thickness plates, where the cutting speed far exceeds that of Oxy-Fuel cutting.

In contrast, plasma cutting is not suitable for all non-conductive materials such as wood, stone, plastic, glass, composite materials (such as carbon fiber unless it has a conductive layer), and concrete. This is because a conductive circuit cannot be formed.

Laser Cutting

Ideal for carbon steel, stainless steel, especially thin sheets and medium-thickness plates. Laser cutting offers unmatched advantages in terms of precision and speed. Fiber lasers deliver excellent results when cutting carbon steel. Materials that can be cut but are not optimal include aluminum, brass, galvanized sheet metal, etc. Among these, aluminum and brass have extremely high reflectivity to lasers, especially at the commonly used wavelengths of fiber lasers. This not only wastes energy and reduces efficiency but the reflected laser can also severely damage the optical components inside the laser. Special anti-reflective technology, higher power, and optimized parameters are required for safe cutting, and the cutting speed and quality are typically inferior to those achieved when cutting steel. Materials that are highly unsuitable or extremely difficult to cut are primarily pure copper (Pure Copper), as its reflectivity is even higher than aluminum's, posing a significant challenge to lasers and making effective continuous cutting nearly impossible.

Waterjet Cutting

Suitable for cutting almost any material. Waterjet cutting is a purely physical cold cutting process that uses the kinetic energy of abrasives and water flow to erode the material. Therefore, it has no restrictions on material type and can cut metals, non-metals, composite materials, alloys, and even layers of dissimilar materials. It is the most versatile cutting method available.

Wire EDM (Electrical Discharge Machining)

Wire EDM is highly suitable for all conductive metals, utilizing electrical discharge erosion. It only requires the material to be conductive. It is particularly adept at cutting high-hardness conductive materials (such as quenched mold steel and cemented carbide) because the machining process is virtually unaffected by material hardness. This technology is not suitable for all non-conductive materials, such as ceramics, gemstones, most plastics, and composite materials.

Mechanical Cutting

The ability of mechanical cutting mainly depends on the hardness and strength of the cutting tool. As long as the cutting tool is harder and stronger than the workpiece material, cutting can be performed. However, cutting high-hardness materials (such as hardened steel) will cause rapid wear of the cutting tool, resulting in very high costs.

Overview of the suitability of various cutting methods for metals

Cutting method	Very suitable metals	Suitable but not optimal metals	Unsuitable/cannot be cut metals
Oxy-Fuel cutting	Low-carbon steel (most suitable)	Low-alloy steel	Stainless steel, aluminum, copper, cast iron, titanium, and all other non-ferrous metals
Plasma cutting	All conductive metals: stainless steel, aluminum and aluminum alloys, carbon steel, copper/brass, galvanized sheet metal	None (Effective on all conductive metals)	All non-conductive materials: such as stone, wood, plastic, glass, ceramics, concrete, etc.
Laser cutting	Carbon steel (especially thin to medium-thick plates), stainless steel	Aluminum/aluminum alloys (high reflectivity, requires specialized parameters and equipment), brass, galvanized sheet metal	Copper (pure copper, high reflectivity, extremely difficult to cut)
Waterjet cutting	Any material (metal and non-metal)	None (applies to all)	None
Wire EDM cutting	Any conductive material (metal)	None (works well on all conductive metals)	All non-conductive materials
Mechanical cutting	Any material (metal and non-metal)	None (applicability depends on tool strength)	None (but high-hardness materials cause severe tool wear)

Finally, when using and selling the product, you need to consider the following factors comprehensively to determine the appropriate cutting method:  

1. Material type: This is the primary factor. Is it carbon steel, stainless steel, aluminum, copper, or non-metallic? Different materials have varying degrees of adaptability to cutting methods (e.g., oxy-fuel cutting cannot be used on stainless steel and aluminum).

a. When primarily processing thick carbon steel plates, oxy-fuel cutting should be the first consideration, as it offers the advantages of low cost and high efficiency.  Weldynasty offers reliable cutting torch from various levels and sizes, together with regulators, hose and weld gloves.

b. When processing mixed materials (e.g., stainless steel, aluminum, and carbon steel) or various non-ferrous metals, plasma cutting is a widely accepted technical option. Compared to Oxy-Fuel cutting, it has the core feature of “one machine for multiple uses, capable of cutting anything (conductive metals),” with fewer limitations than Oxy-Fuel cutting.  You can also find our Iron Man series or Speed Blade series P80 electrodes and nozzles, specially designed for plasma cutting, with extrodinary reliability and wide applicability.

c. If high precision and cut quality are required, and the primary focus is on thin plates, laser cutting can be considered. However, it is essential to note whether high-reflective materials (aluminum, copper) are being cut, along with the potential challenges and costs associated with such materials.

d. When processing special composite materials, heat-sensitive materials, or various non-metals: waterjet cutting should be the primary consideration. Its unique value of “cold cutting, no thermal damage, and versatility” makes it irreplaceable.

e. When your production line or your client's production line requires the manufacture of high-precision molds or parts, wire cutting should be the primary choice. It has obvious advantages and irreplaceability in terms of precision and processing high-hardness materials.

2. Sheet thickness: Different cutting methods have their suitable and efficient thickness ranges. Refer to the data in the table.

3. Budget range: This includes initial equipment investment and long-term operational costs (consumables, gas, electricity, maintenance). For example, laser equipment is expensive but may have moderate subsequent costs; waterjet equipment has medium-to-high costs but very high operational costs.

4. Requirements for cutting quality and precision: Is secondary processing required? What are the requirements for cut surface smoothness, perpendicularity, and precision? For example, precision parts may require laser or wire cutting.  

5. Production efficiency requirements: Is a high production cycle rate required? For example, plasma cutting has a clear advantage in terms of speed.  

6. Environmental protection and safety: Does the workshop have strict environmental protection, noise, and dust requirements? For example, waterjet cutting and mechanical cutting are more environmentally friendly.